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SILVER LAKE COMMISSION
Meeting will be held in person and via weblink.
Meeting Link: https://cityofdover.webex.com/cityofdover/j.php?MTID=mee7c75d88c429addfea71ee82ddaf07d
Dial: 1-650-479-3208 Access code: 2533 069 2943 Event password: DoverSLC
AGENDA
July 30, 2025
5:30 PM
Large Conference Room
1. Call to Order / Welcome Members
2. Review of Minutes
3. Vacant Position
4. Dover Police Update
5. Earth Day
6. Riparian Buffers Discussion Follow Up
7. Update on Silver Lake Water Quality
8. Silver Lake Master Plan
9. Silver Lake Resolution
10. Silver Lake Draw Down
11. Watershed Map
12. Meeting Schedule (as needed/quarterly at most)
13. Adjournment
THE AGENDA ITEMS AS LISTED MAY NOT BE CONSIDERED IN SEQUENCE. PURSUANT TO 29 DEL. C. §10004(E)(2), THIS AGENDA IS SUBJECT TO CHANGE TO
INCLUDE THE ADDITION OR THE DELETION OF ITEMS, INCLUDING EXECUTIVE SESSIONS, WHICH ARISE AT THE TIME OF THE MEETING.
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Silver Lake Commission
March 20, 2024
5:30 PM
In person & Via Weblink
**DRAFT**
Members Present Staff & Guests
John DeMarie Tricia Arndt, 3rd District City Councilwoman
Kathy Doyle Carolyn Courtney, Parks & Recreation Staff
Marie Kozel, Chair Bryn Wambaugh, City of Dover Environmental Scientist
Michael Lewis Officer Killen, City of Dover Police (web)
William Satchell
Anthony Morris (web)
WELCOME & CALL TO ORDER
The meeting was called to order at 5:30 PM
MEMBER & STAFF INTRODUCTION
Brief Introductions around the table.
MEETING MINUTES
(AN ERROR OCCURRED ON THE RECORDING – STILL LOOKING TO RECOVER THIS INFORMATION)
NAMING/DEDICATION OF CITY PARKS
Councilwoman Arndt is proposing a new naming policy for buildings and facilities in the municipality, as well as a general
naming policy. The current process in Dover for naming parks and other spaces is informal and lacks a thorough vetting process.
Councilwoman Arndt noted instead of creating an ad hoc committee or using the existing committee to review naming
petitions, establish criteria, and ensure a fair and equitable process that honors the city's history and culture, I would
appreciate your input. The discussion in the meeting was about whether or not to name things after people in the city. The
preference was expressed for alternative ways of honoring individuals, such as memorial bricks, benches, and trees. There
were concerns about the number of requests to name things and the limited number of parks available. The brick program at
the former fireman’s moment site is an idea for offering memory in lieu of naming a park. Discussion & feedback was
supportive. Comments are still welcome, please forward onto Ms. Courtney, Ms. Kozel or Mrs. Arndt.
WATER SYSTEM IMPROVEMENT PROJECT UPDATE
Ms. Courtney reported that Mr. Lyon was unable to attend this meeting, however, the project is on target for completion in
April 30. The parks staff will be following the project to ensure the parking area is cleaned up and left in good condition. In
discussion, it was noted that this is not a restroom facility, and the gates will remain locked to the public.
DOVER POLICE – PARK REPORT UPDATE
Officer Killen reported that they would respond if there were issues with alcohol consumption or disturbances. There were
very few calls since the last meeting report. A couple psychiatric calls, but no trend was established. We were made aware of
large DSU party at Silver Lake Park. Proactive measures prevented this event from happening as a permit was not issued
through the city. It was communicated to the organizers that the party would not be tolerated. Myself and another officer
stayed late to secure the park and other parks in the area were secured as well.
He welcomed questions.
Ms. Kozel noted if we see a large gathering, how would we know if there is a permit. Mr. Killen responded if alcohol and/or DJ
are seen, then it is not permitted as we don’t allow that. If there is question, we can ask to see their permit. If you have a
concern, just give the department a call and we’ll check it out. Ms. Courtney added, that inflatable bounce house, or excessive
loud music that is not allowed. Those with a permit are given this information. It was discussed putting up a notice of
“reservation” or something to that affect. Ms. Courtney noted she would discuss this with Mr. Ridgeway, our grounds
superintendent.
There are camera at Silver Lake with access to limited to the police department, but there is a possibility of sharing access with
the Parks and Recreation department in the event of researching a particular activity.
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Mr. Morris compliments the Parks department on their permitting process. We go there, we don’t have a problem as we have
the permit and it’s been helpful.
A brief discussion on locking and opening gates at Silver Lake and our other parks as well.
UPDATE ON SILVER LAKE PARK PROJECTS & MAINTENANCE UPDATES
Ms. Courtney reported that Mr. Eaton has tendered his registration and will be leaving the city at the end of the month.
Bally’s will be returning for another Earth Day projects at Silver Lake Park and also Schutte Park. Bally’s staff have been a great
group of volunteers for park projects and we look forward to working with them again. Requests for park clean-ups are being
sent to me and I’ll coordinate accordingly with Mr. Ridgeway. A brief discussion on the various groups that have volunteered
for park clean-up events.
MAYORS REGATTA 2024
Ms. Courtney reported a target date of early fall or end of September is begin discussed and we hope to partner
with Good Neighbors (formerly NCALL). This could increase the event attendance, introduce the lake and offer a
day of fellowship at the park.
RIPARIAN BUFFER
Mrs. Doyle asked for an update from Ms. Wambaugh regarding the causeway (State Street bridge). Ms. Wambaugh shared a
brief history of the grounds department being in the Public Works Department but they are not park of the Parks & Recreation
Department. The area was once maintained by the grounds staff but then public works was told to mow the area and why we
do so today. We only have a budget for mowing, there is no budget for plantings, also there is no staff to maintain plantings.
We do not have budget or staff to maintain any plantings along this area. We do not have the equipment to do so within the
city. Mrs. Doyle feels it is a law that say there has to be a riparian buffer here. She could not site the actual law and would get
that to us. Other members spoke up and said the area looks really good they way it is being maintained now. The grass offers a
buffer for water prior to reaching the lake. Discussion took place on beneficial plantings verses mowing this area. Mrs. Doyle
feels the problem is the grass just allows the water and junk from the road to get into the water. With deep roots of native
plants that would help reduce the water getting into the lake. Mrs. Doyle is concerned with herbicides that are sprayed
although she has been told by Sharon Duca that it is a water safe herbicide. Mrs. Doyle noted it sounds like Mirror Lake is being
taken care of properly but I don’t feel like Silver Lake is being taken care of properly with area like the causeway not having
native plants.
Mrs. Arndt noted she had a constituent who was interested in working on riparian buffers. Mrs. Arndt noted she would send
that information to Ms. Courtney.
Grass is working as the buffer, we do not have staff or equipment to plant the native plants for an area that is show no signs of
erosion. At this time, there is no plan for any plantings along the causeway. Other members noted a lot of healthy wildlife in
the lake area. Eagles, hawks, etc. it appears to be a healthy habitat. Ms. Kozel noted that water quality has come back some
from the previous projects such as the Mirror Lake plantings. A discussion on water quality tests performed by DRNEC. Ms.
Courtney will send out a link to the members for the DRNEC water quality site. https://dnrec.delaware.gov/watershed-
stewardship/
Mrs. Doyle was requested to send the actual law or information on the law that she feels the city is violating.
ENDING COMMENTS
Ms. Courtney noted she is most likely retiring in October of 2024. (Turns out it’s 2025 now)
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Silver Lake Commission
April 24, 2025
5:30 PM
In person & Via Weblink
**DRAFT**
Members Present Staff & Guests
Kathy Doyle Tricia Arndt, 3rd District City Councilwoman
Michael Lewis Carolyn Courtney, Parks & Recreation Staff
Anthony Morris Nichole Arnold, Parks & Recreation Staff
Roger Ridgeway, Parks & Recreation Director
Bryn Wambaugh, City of Dover Environmental Scientist
Aireal Vickers, City of Dover Environmental Scientist
Charles Salkin 3rd District Resident
WELCOME & CALL TO ORDER
The meeting was called to order at 5:30 PM
MEMBER & STAFF INTRODUCTION
Brief Introductions around the table.
MEETING MINUTES
WITHOUT A QUORUM, MINUTES COULD NOT BE APPROVED.
STAFF WAS REQUESTED TO SEND OUT TO OUR MEMBERS SO THEY CAN REVIEW AND ADDRESS AT THE NEXT MEETING, ALONG WITH THESE
MINUTES
CALL TO ORDER/VACANT POSITIONS
Mrs. Doyle stepped up as acting chair for tonight’s meeting. The commission has 7 active members, 4 current city members,
there will be 2 seats available with 1 still being empty. Ms. Doyle asked about having quarterly meetings with consideration to
staff workload? Staff noted meetings do not have to be quarterly, and that if there is an issue that needs input/review by the
commission, a meeting would be called accordingly. Mrs. Doyle inquired about the members getting together offsite without
the staff to only discuss ideas and concerns of the park and lake. Ms. Courtney noted as they are a subcommittee and as long
as nothing is voted on or discussed that would have a financial or other liability to the city, they should be ok, but she will
confirm with the clerk’s office.
STORMWATER AND EARTH DAY UPDATES
Ms. Wambaugh and Ms. Vickers presented to the group info on Earth Day. The city has a system called The National Polluting
Discharge Elimination System also known as MPDS. The event that was held served purpose of public involvement. There was
also a Storm water day that was hosted the next day with informative information about storm water day, how to join the next
years Earth Day event, and a thank you to the presenters. The events that were hosted throughout the week were a nature
walk, which was a guided walk, the screening of the Lorax film at the Dover library, litter pick up day with very little help from
the community but hoping next year more will attend. They collected a shopping cart and ½ of a 90-gallon trash bag. Bryn and
Ariel were excited about the community coming together for Earth Day and look forward to doing it again next year, they would
like to continue to do this during school’s spring breaks to have more children and families to attend.
DOVER POLICE – PARK REPORT UPDATE
Dover Police attempted to join the meeting via Webex but we were having issues, so they were unable to join. Dover Police has
shared to Ms. Courtney that they are aware of large gatherings/parties happening on Silver Lake and they are actively looking
for graduations, and DSU having their pop-up parties. They are also working with the County to stay on the same page.
UPDATE ON SILVER LAKE PARK PROJECTS & MAINTENANCE UPDATES
Ms. Courtney reported that city staff have placed signs out at Silver Lake Park at pavilions 1 and 2 that state the upcoming
events. She is hoping that those signs will help the community know when events take place and that a permit is recommended
for using the pavilions.
Mr. Ridgeway reported Bally’s returned for another Earth Day project at Mallard Pond. Bally’s staff has been a great group of
volunteers for park projects, they helped plant 2 trees, 5 shrubs and helped mulch 1 playground. We look forward to working
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with them again. Requests for park clean-ups are being sent to Ms. Courtney, and she will coordinate accordingly with Mr.
Ridgeway.
SILVER LAKE AND ST. JOHNS RIVER UPDATES
Mrs. Doyle presented information on the latest water levels at Silver Lake and St. Johns River, she stated that while our rivers
are the most polluted in the Country other states are not testing their waters for drinking water. Mrs. Doyle stated that
although the water test results from the state continues to be concerning, the fish count has gone from 1 to possibly 12 to
consume. Mrs. Doyle would love to have our beach at Silver Lake open again for swimming one day, however she felt the City’s
budgetary reasons we would not be able to staff lifeguards at this time. Mrs. Doyle brought up that Garrison Lake does have
swimming and she would like to have something like that here in the City of Dover. Ms. Courtney stated that as much as the
city would love to have swimming access the city was paying more to have our lifeguards keep park users out of the water than
in the water due to water quality each day.
KAYAK AND BOATING CONCERNS ON SILVER LAKE
Ms. Courtney stated that she had a complaint called in about seeing kayaks and boat trailers in the boat ramp area that had no
stickers on the trailers. The gentleman stated that he pays every year to have a boat permit to be on Silver Lake and none of
these boats did. Mrs. Arnold, who used to work in the Planning and Inspections department and issued boating permits on a
daily basis stated that kayaks are never given stickers, only motorized boats. Any approved vessel that is placed into Silver Lake
is required to have a boating permit/sticker. Mrs. Arnold and Ms. Courtney discussed maybe some changes for kayaks receiving
stickers for their boats to keep better track of who and who do not have a boat permit.
MEETING DATE
The attending members have set the next meeting date as July 30. Staff will confirm availability and post the notice once
confirmed.
ENDING COMMENTS
Ms. Courtney noted she is retiring in October of 2025 and possibly Mrs. Arnold will be taking her spot.
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PARKS, RECREATION, AND COMMUNITY
ENHANCEMENT COMMITTEE
AGENDA
June 13, 2011 - 12:00 Noon - City Hall Conference Room - City Hall - City of Dover
Public comments are welcomed on any item and will be permitted at appropriate
times. When possible, please notify the City Clerk (736-7008 or e-mail at
CityClerk@dover.de.us) should you wish to be recognized.
AGENDA ADDITIONS/DELETIONS
1. Silver Lake Revitalization - Phase III
/tm
S:\AGENDAS & MINUTES\Committee-Agendas\2011\06-13-2011 PR&CE Revised.wpd
THE AGENDA ITEMS AS LISTED MAY NOT BE CONSIDERED IN SEQUENCE. THIS AGENDA IS SUBJECT TO CHANGE TO
INCLUDE THE ADDITION OR THE DELETION OF ITEMS, INCLUDING EXECUTIVE SESSIONS.
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Park Drive Resident Opinions of Proposed Plantings
St. Jones Watershed Coordinators, Brittany Benson and Jennifer Bowman,
visited the homes of several residents along Park Drive to inquire about their
opinions of the proposed plantings. The following is a summary of their
feedback:
General consensus among all surveyed residents was that the planting
is very welcomed.
o The constant presence of goose refuse in Memorial Park
was and continues to be a major concern. Thus, majority of
residents have completely stopped using the park.
All residents had a positive response to planting the buffer along the
lake, especially if it helped deter the geese from using the area.
Increasing the amount of vegetation was desired by all; with
particular interest in year-round color because of the visual interest
that the buffer will offer.
Strong responses concerning a [mulched] pathway:
o Some residents were very apprehensive to create a
walkway. There were particular concerns about
redistribution of mulch in times of flooding.
o Other residents desired a pathway as a way to enjoy the park
and vegetation up close.
A few residents commented that gaps should be left in the vegetation
to allow room for fishermen and park visitors to access the water.
Mirror Lake sedimentation and dredging was also a common concern.
There will be a public workshop to discuss this separate issue in the
fall.
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Silver Lake Park Revitalization Project
Phase III – Park Drive
City of Dover
Silver Lake Commission
DNREC
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Background
• Silver Lake is located in the St. Jones River Watershed
in Kent County, Delaware
• DNREC established a level of Total Maximum Daily
Loads (TMDLs), as mandated by the Clean Water Act,
for the St. Jones River Watershed in 2006 because of
the impaired status of the water
• The Silver Lake sub-watershed contained the most
opportunities to control pollution out of the entire
watershed
• The St. Jones Tributary Action Team developed a
pollution control strategy to reduce pollutant loads to
the TMDLs
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The Clean Water Act 303d List indicates that the
St. Jones River Watershed impairments include:
• Nutrients (elevated nitrogen and phosphorous)
• Bacteria (pathogens)
• Low dissolved oxygen
• Habitat degradation
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The Silver Lake Park Revitalization
Project came from St. Jones Tributary
Action Team recommendations
Tributary Action Teams St. Jones River watershed
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St. Jones TAT recommendations:
• A 100 foot vegetated or forested riparian buffer zone
should be required within the watershed for all water
bodies
• Vegetation within the buffer should be made up of
“recommended plantings” of native species
• Buffers should be maintained in perpetuity and should
be managed to maintain water quality benefits
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Total acreage that has been planted in
Phase I and II thus far
Location Acres
East side of St. Jones 0.525
West side of St. Jones 0.145
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Vision of SLPR Project Area
• 100-foot buffer area targeted for
planting
• Mix of native plants for all-year
interest
• Large lawn areas for group
activities, plus smaller areas for
readers, “lunchers” and sunbathers
• Fishing locations
• Mowed grass strip between
sidewalk & planting beds
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Buffer will be for water quality as well
for the aesthetics
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Silver Lake Park popular fishing areas*
*We’re looking for input of other fishing spots, especially along Park Drive
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Some Known Problems/Issues of
Memorial Park & Mirror Lake:
• Water quality
• Poor habitat value
• Canada Goose waste
• Sedimentation of Mirror Lake
• Periodic flooding
Picture of direct discharge of stormwater
into the St. Jones
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Flooding of the St. Jones River along Park Drive
in April 2007
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We’re not only creating buffers…
• Removing invasive vegetation
• Restoring the banks of the St. Jones
near the dam
• Retro-fiting some stormwater
discharges
• Creating some wetlands within the
Park
Photo of biolog that will help
establish wetland vegetation
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Proposed Planting Locations
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Proposed Planting Plans
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Progress to date
• 3 plantings have occurred (65%
done) in Phase I
• Started working on Phase II and
Phase IV (Central Middle School)
• For Phase II, the design has been
completed and the project is
currently being bid out to
contractors
• Started to plant phase III
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Next Steps
• Tweaking of planting plans based on feedback
o Planting to resume in the fall
• Volunteers very much appreciated to help plant!
o Sign-up sheet available at end of meeting
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Satellite Image:
Proposed Landscape
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Satellite Image:
Proposed
landscape
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Satellite Image:
Modified Landscape:
Less trees
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Satellite Image:
Proposed
landscape with
less trees
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More
Trees
Less
Trees
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Park Drive Resident Opinions of Proposed Plantings
St. Jones Watershed Coordinators visited the homes of several
residents along Park Drive to inquire about their opinions of the
proposed plantings.
• General consensus among all surveyed residents was that the
planting is very welcomed.
All residents had a positive response to planting the buffer
along the lake, especially if it helped deter the geese from
using the area.
Increasing the amount of vegetation was desired by all; with
particular interest in year-round color because of the visual
interest that the buffer will offer.
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City of Dover
Silver Lake Sub-
Watershed
Implementation
Strategy
For the Silver Lake
Commission
Lara Allison
6/30/2011
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St. Jones River Watershed
Pollution Control Strategy
A Watershed-Based Strategy to Implement
Total Maximum Daily Loads in Delaware
December 2012
Prepared for the St. Jones River
Tributary Action Team
By the Watershed Assessment and Management Section Frank Piorko, Director
http://de.gov/pollutioncontrolstrategy Division of
Watershed Stewardship
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ST. JONES RIVER WATERSHED POLLUTION CONTROL STRATEGY .............................. 1
INTRODUCTION AND BACKGROUND ............................................................................... 1
LANDUSE .................................................................................................................................. 1
SOURCES OF POLLUTION ..................................................................................................... 5
PROGRESS TO DATE .............................................................................................................. 5
Agriculture .............................................................................................................................. 6
Open Space ............................................................................................................................. 7
Onsite Wastewater .................................................................................................................. 7
Stormwater .............................................................................................................................. 7
Total Progress to Date ............................................................................................................. 8
Additional Progress Items ..................................................................................................... 10
Overall Nutrient Load Reduction Progress ........................................................................... 11
ST. JONES RIVER WATERSHED POLLUTION CONTROL STRATEGY
RECOMMENDATIONS .......................................................................................................... 12
BROAD PURPOSE .............................................................................................................. 12
SPECIFIC GOALS ............................................................................................................... 12
Strategy Periodization ........................................................................................................... 13
Nutrient Reducing Recommendations .......................................................................................... 13
Nutrient Reducing Recommendation 1 – Riparian Buffers ...................................................... 13
Nutrient Reducing Recommendation 2 – Open Space ............................................................. 19
Nutrient Reducing Recommendation 3 – Open Space Education ............................................ 21
Nutrient Reducing Recommendation 4 – Sewer Repair ........................................................... 24
Nutrient Reducing Recommendation 5– Septic Pump Out and Inspection .............................. 24
Nutrient Reducing Recommendation 6 – Cesspools and Seepage Pits .................................... 26
Nutrient Reducing Recommendation 7 – Septic Removal ....................................................... 27
Nutrient Reducing Recommendation 8 – Performance Standards ........................................... 28
Nutrient Reducing Recommendation 9 – Stormwater Utility................................................... 30
Nutrient Reducing Recommendation 10 – Stormwater Best Management Practices............... 31
Nutrient Reducing Recommendation 11 – Impervious Cover.................................................. 32
Nutrient Reducing Recommendation 12 – Stormwater Retrofits ............................................. 34
Nutrient Reducing Recommendation 13 – Stormwater Education ........................................... 35
Nutrient Reducing Recommendation 14 – Agricultural BMPs ................................................ 37
Nutrient Reducing Recommendation 15 – Nutrient Management Act ..................................... 39
Nutrient Reducing Recommendation 16 – Stream Monitoring ................................................ 43
ANALYSIS FOR TMDL ACHIEVEMENT AND COST ....................................................... 46
IMPLEMENTATION PROGRAMS ........................................................................................ 50
Coastal Nonpoint Program – 6217........................................................................................ 50
The Delaware Forest Service ................................................................................................ 50
DNREC -- Groundwater Discharges Section ....................................................................... 51
DNREC – Nonpoint Source Program ................................................................................... 51
DNREC-Sediment and Stormwater Program ....................................................................... 51
DNREC - Surface Water Discharges Program ..................................................................... 52
DNREC – Water Supply Section – Groundwater Protection Branch ................................... 52
Local Governments ............................................................................................................... 53
Nutrient Management Commission ...................................................................................... 53
Office of State Planning Coordination.................................................................................. 53
Soil and Water Conservation Districts.................................................................................. 53
References ..................................................................................................................................... 54
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Appendix A - 7426 TMDLs for the St. Jones River Watershed, Delaware.................................. 58
Appendix B - Tributary Action Team Letter to Secretary Hughes ............................................... 60
Appendix C - Public Talk –Real Choices ..................................................................................... 69
Appendix D - BMP Nutrient Reduction calculations ................................................................... 75
Appendix E - BMP Cost Calculations .......................................................................................... 91
List of Figures
Figure 1 - Map of St. Jones River Watershed as of 2006 ............................................................... 2
Figure 2 - St. Jones River Watershed Land Use Distribution ......................................................... 4
Figure 3 - The year geometric mean of Entrococcus Bacteria in the St Jones River ................... 10
Figure 4 - Streams (outline in green) within Dover that require riparian buffers ......................... 14
Figure 5 - Riparian Buffers in the St. Jones Watershed ................................................................ 16
Figure 6 - Percentage of Non-Farm Fertilizer Sold in Delaware by Year .................................... 21
Figure 7 - Total Nitrogen loads in the St Jones watershed from 2003 to 2010 ............................ 45
Figure 8 - Total Phosphorus loads in the St Jones watershed from 2003 to 2010 ........................ 45
Figure 9 - Total Phosphorus Reduced in the St. Jones Watershed ............................................... 48
Figure 10 - Total Nitrogen Reduced in the St. Jones Watershed .................................................. 48
Figure 11 - Total Strategy Implementation Costs ......................................................................... 49
List of Tables
Table 1 - St. Jones River Watershed TMDL Segments .................................................................. 3
Table 2 - Summary of 2007 Land Use in the St. Jones River Watershed....................................... 3
Table 3 - Land use change from 1997 to 2007 within the St. Jones Watershed ............................. 4
Table 4 - Agricultural Best Management Practice Reductions as of March 2012 in the St. Jones
Watershed ....................................................................................................................................... 6
Table 5 - Nutrient Reduction Resulting from Onsite Wastewater Treatment and Disposal System
Best Management Practices as of August 2009 .............................................................................. 7
Table 6 - Implemented Stormwater Best Management Practices as of Spring 2012...................... 8
Table 7 - Typical bacteria, suspended solids, and nutrient reduction from stormwater best
management practices ..................................................................................................................... 9
Table 8 - Load reduction needed based upon 2007 land use to achieve TMDL reduction of 40%
for nitrogen and phosphorus ......................................................................................................... 12
Table 9 - Kent County Ordinance (187-78) and the City of Dover required setbacks from water
bodies ............................................................................................................................................ 15
Table 10 - Acreage included in setback by means of Kent County Ordinance §187-78 or
protected by §187-77* .................................................................................................................. 17
Table 11: Effectiveness of various Stormwater BMPs to reduce nutrient (TN & TP) Loads ...... 32
Table 12: Agricultural BMP Costs ............................................................................................... 39
Table 13. Percent changes in fertilizer and manure application rates by county as a result of the
2002 Nutrient Management Law (data from 2007 DCP Survey) ................................................. 41
Table 14: Best Management Practices Goals for Achieving the St Jones Watershed TMDL
Reductions..................................................................................................................................... 47
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ST. JONES RIVER WATERSHED POLLUTION CONTROL STRATEGY
INTRODUCTION AND BACKGROUND
The St. Jones watershed is located in Kent County, Delaware, with the Delaware Bay along its
eastern border, the Choptank River watershed of the Chesapeake Basin to its west, the Leipsic
River and Little Creek watersheds to the north and northeast, respectively, and the St. Jones
watershed to its south (DNREC 2005). The watershed is one of sixteen watersheds in the
Delaware Bay and Estuary Basin, and one of nine watersheds in Kent County (USGS HUC-10).
The watershed is comprised of 57,735 acres of land (DNREC 2005) and contains six
municipalities: Dover, Wyoming, Camden, Woodside, Magnolia, and Bowers Beach.
The watershed gets its name from the area’s major water system, the St. Jones River, which is 22
miles long and begins in the western portion of Kent County, flowing in a southeasterly direction
until it empties into the Delaware Estuary at Bowers Beach. Due to the tidal nature in the lower
half of the St. Jones River, the flow decreases and the waters become turbid in these areas. The
surrounding soils near the river are considered to have high to very high agricultural
productivity.
According to 2007 state land use Geographic Information System (GIS) data, agriculture remains
the number one land use in the watershed (37.4%), followed by urban land uses (33.3%),
wetlands (17.5%), forests (8.4%), barren land (3.2%). Although only 30% of the watershed is
classified as urban/residential, the watershed has the highest population of all watersheds in Kent
County (DNREC 2005).
Table 1 lists the water bodies within the St. Jones River watershed listed on the State of
Delaware’s 1998, 2002, 2004, and 2006 303(d) reports. There are a total of eight listed water
segments: 2 tidal segments of the St. Jones River, 3 freshwater stream segments, and 3
freshwater lakes or ponds. These segments contain nutrients, dissolved oxygen (DO), and
bacteria, with the most probable source of pollutants identified as nonpoint sources. The total
maximum daily load (TMDL) development in the St. Jones River watershed addressed these
water quality impairments and presented TMDLs that are aimed at improving water quality in
the listed segments.
LANDUSE
Land use information for the year 2007 is presented in Table 2 and Figure 2. The St. Jones River
watershed is approximately 57,735 acres (90 mi2) and is primarily non-urban (66.7%), with
approximately 33.3/4% of that land used for agriculture. By 2007 the acreage of
urban/residential lands has increased while agricultural and forested land has decreased as
presented in Table 3.
1
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Figure 1 - Map of St. Jones River Watershed as of 2006.
2
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Table 1 - St. Jones River Watershed TMDL Segments
Size
Water Body ID Segment Description Parameters
Affected
From Old Lebanon Bridge to the mouth of
DE290-001-01 Lower St. Jones 8.3 miles Bacteria, DO, nutrients
Delaware Bay
From the dam at Silver Lake to Old
DE290-001-02 Upper St. Jones 6.7 miles Bacteria, DO, nutrients
Lebanon Bridge at Road 357
From the headwaters to the confluence with
DE290-002 Isaac Branch 9.1 miles Bacteria, DO, nutrients
St. Jones River, excluding Moores Lake
From the headwaters to Silver Lake in
DE290-003 Fork Branch 7.7 miles Bacteria, DO, nutrients
Dover
From below Derby Pond to the confluence
DE290-004 Tidbury Branch 3.8 miles Bacteria, DO, nutrients
with the St. Jones River
DE290-L01 Moores Lake 27.1 acres Lake east of Camden Bacteria, DO, nutrients
DE290-L02 Silver Lake 157.8 acres Silver Lake at Dover Bacteria, nutrients
DE290-L03 Derby Pond 23.1 acres Pond south of Wyoming Bacteria, nutrients
Table 2 - Summary of 2007 Land Use in the St. Jones River Watershed
Land Use Area (a) % Total Area
Agriculture 21,596 37.4
Forest 4,858 8.4
Pasture/Rangeland 415 0.7
Urban/Built-up Land 19,206 33.3
Water 1,552 2.7
Wetland 8,689 15.1
Others 1,419 2.4
Total 57,735 100.0
3
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Figure 2 - St. Jones River Watershed Land Use Distribution
Table 3 - Land use change from 1997 to 2007 within the St. Jones Watershed
1997 2007 Change
Land Use % Total Area % Total Area
Agriculture 44.4 37.4 -6.4%
Barren/Open 1.8 3.2 1.4%
Urban 26.9 33.3 6.4%
Forest Land 9.8 8.4 -1.4%
Wetlands/Water 17.1 17.5 0.4
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SOURCES OF POLLUTION
Both nonpoint sources and point sources of pollution can be found in the St. Jones watershed.
Nonpoint source pollution can be defined as pollution caused by land use practices that occur
over large areas. Unlike point source pollution, which deposits pollution into a water body at a
specific location, nonpoint sources reach waterbodies at nonspecific locations through
groundwater seepage or agricultural runoff along a stream.
The land use distribution in the St. Jones River watershed was generalized into the groups shown
in Table 2: agriculture, forest, pasture/rangeland, urban/built-up, wetlands and others. Each of
these land uses has a different possible source of pollution that is deposited directly or indirectly
into the water system. The “other” land use category includes transitional construction and
inland natural sandy areas. Forested areas, made up of deciduous, evergreen, and mixed forests,
account for just over 8.4 percent of the watershed. Nutrients and bacteria from the resident wild
animals, and organic material from the native plants, are common sources of nonpoint pollution.
Wetland areas make up 15.1 percent of the total watershed and are home to many species of
plants and wildlife that produce organic, nutrient, and bacterial wastes. Approximately 37.4
percent of the St. Jones River watershed is classified as agricultural, including cropland, farm
related buildings, idle fields, orchards, and land used for nurseries. Possible nonpoint sources of
pollution from these areas include bacteria and nutrients from animal feed lots, organic material
from plants, nutrients from industrial fertilizers, and particulate and dissolved nutrients in runoff.
Pasture/rangeland comprises less than 0.7 percent of the watershed, and includes pasture and
herbaceous, brush and mixed rangelands. Nutrients and bacteria from animal grazing or
production are common sources of nonpoint pollution. Urban land has a higher amount of
pollution due to a lower amount of pervious land. Examples of urban land are: roads, salvage
yards, mixed urban, professional retail, single family dwellings, utilities and warehouses.
Among the causes of pollution from urban land use are nutrients and bacteria in runoff from
impervious surfaces, nutrients and bacteria from septic systems, nutrients from residential
fertilizers, industrial wastes and domestic pet wastes. In 2007, approximately 33.3 percent of the
St. Jones River watershed is urban or built-up. Based on the land use data, the St. Jones River
watershed is primarily non-urban (70%); and non-point sources (NPS)_ are an important source
of pollution in the watershed. There are two active National Pollutant Discharge Elimination
System sites (NPDES) permitted in the watershed but these are non-contact cooling water
discharges with low loadings of pollutants: Reichhold Chemicals Dover Plant and Dover McKee
Run Power Plant. Therefore, NPSs are the dominant source of pollution in the watershed.
PROGRESS TO DATE
Six years have passed since the TMDL for the St. Jones River was promulgated using pollution
levels from 2006. Since that time, population and pressures from development have increased
throughout the watershed. However, stormwater and wastewater regulations have improved, and
farmers have increased their use of best management practices (BMPs). Increased use of BMPs
in all sectors reduces nutrient loading and contributes to progress towards achieving water
quality standards.
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Estimated water quality improvement resulting from the installation of best management
practices after the TMDL baseline was calculated and the subsequent nutrient reductions from
those BMPs are presented in the following sections. Scientists researched the nutrient load
reduction efficiencies associated with these practices in order to estimate pollution reductions.
Appendix D documents those calculations and Appendix E estimates the associated costs.
Agriculture
Since the baseline period, the agricultural community has reduced a significant amount of
nonpoint source nitrogen and phosphorus, leading the efforts to curtail nonpoint source loadings.
From the baseline to 2006, multiple BMPs have been implemented and the Delaware Nutrient
Management Act was passed. As of January 2007, all farms that apply nutrients to 10 acres or
more are required to have Nutrient Management Plans (NMPs). Subsequent Farm Bills have
also led to increased funding levels of cost-share programs for BMPs that protect the
environment, especially water quality.
Table 4 - Agricultural Best Management Practice Reductions as of March 2012 in the St.
Jones Watershed
Load Reduction
(lb/day)
Acres TN TP
Cover crops acreage for 2011 890 10.79 0.38
CRP Practices (data from 2004 and earlier)
Shallow water areas for wildlife (CP9) 13.8 0.3 0.03
Existing Trees (CP11) 3 0.1 0.00
Grassed waterways (CP8) 0.4 0.0 0.02
Grassed filter strips (CP21) 2.5 0.0 0.23
Wildlife habitat (CP4D) 33.5 0.0 0.23
CREP Practices* (data from 2005 and later)
Grass buffers (CP21AC) 8.5 0.4 0.16
Wildlife Plantings (CP4D) 42.3 1.7 0.70
Hardwood Plantings (CP3A) 130.3 3.6 1.43
Riparian buffers (CP22) 7 0.2 0.12
Shallow water areas for wildlife (CP9) 10.9 0.4 6.20
Wetland Restoration (CP23) 352 11.5 1.51
Critical area planting 14.3 0.1 0.00
Conservation tillage 1981 1.4 0.00
Manure Relocation (annual tons) 646 3.76 2.79
Phytase 1,007.59 0.44
Nutrient Management Plans 21587.6 63.1 51.10
Total 95.33 64.03
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Total Progress to Date:
Estimated Nutrient Reductions 95.33 lbs/day TN; 64.03 lbs/day TP
Estimated Progress to Date Implementation Cost: $2,503,028 (This cost does not include
manure relocation and phytase costs).
Open Space
The Tributary Action Team has made some recommendations for open space, but their
recommendations are more voluntary than regulatory. Using GIS mapping tools to determine
acreage of open space within the St. Jones indicated there are 8,070.9 acres of public lands in the
watershed and approximately 55 % of the public lands are in tidal areas of the watershed.
Total Progress to Date:
Estimated Nutrient Reductions: lbs/day TP unknown; lbs/day TN unknown
Onsite Wastewater
Current septic system pump outs of 100 systems and 18 holding tanks have helped to decrease
the nutrient pollution entering the St. Jones watershed.
Table 5 - Nutrient Reduction Resulting from Onsite Wastewater Treatment and Disposal
System Best Management Practices as of August 2009
Load Reduction (lbs/day)
Number of Tanks TN TP
Holding Tanks (12 18 1.36 0.45
pump-outs/year)
Septic System Pump 100 0.24 0.10
Outs
Total 1.60 0.55
Total Progress to Date:
Estimated Nutrient Reductions: 1.60 lbs/day TN; 0.55 lbs/day TP
Stormwater
In June 1990, the Delaware Legislature passed the Sediment and Stormwater Law to help correct
the State’s water quality and quantity problems. Implementation was initiated in July of 1991,
and addressed sediment control during construction and post-construction, stormwater quantity,
and water quality control. Since this implementation, many BMPs for stormwater have been
implemented and more are constructed each year. The Sediment and Stormwater Regulations
are currently being revised to promote the use of stormwater management techniques that are
more efficient at reducing nutrient loading, heightening awareness of green technology BMPs,
and promoting stormwater management practices based on low impact development and
conservation design.
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Table 6 - Implemented Stormwater Best Management Practices as of Spring 2012
Daily Load
Actual Acreage Reduction From
Best management Practice (BMP)
Treated Stormwater BMP
(lbs/day)
TN TP
Biofiltration/bioswales 276.1 2.35 0.39
Dry ponds 1271.82 1.08 0.25
Filter Strip 8.17 0.07 0.01
Infiltration systems 245.74 2.09 0.34
Sand Filter 8.7 0.06 0.01
Wet Pond 3231.58 16.48 3.23
Street sweeping, Stream bank
restoration and Regenerative step
pool system 4.01 3.08
The City of Dover has developed a storm water management program in response to the United
States Environmental Protection Agency’s (EPA’s) regulation referred to as the Stormwater
Phase II Rule. Under this rule, storm water discharges to certain municipal separate storm sewer
systems (MS4s) are regulated. Specifically, discharges of storm water, to waters of the State of
Delaware, from the storm sewer system owned, operated or maintained by the City of Dover are
regulated and require a NPDES (National Pollutant Discharge Elimination System) permit.
The City of Dover, through the Department of Public Works, received its NPDES/State permit
from the State of Delaware Department of Natural Resources and Environmental Control
(DNREC) in 2003. This permit authorizes the discharge of storm water from the City’s storm
sewer system and requires the implementation of the City’s storm water management program.
Elements of the City’s program include public education and outreach, public involvement and
participation, illicit discharge and elimination, construction site runoff control, post construction
storm water management, and pollution prevention good housekeeping for municipal operations.
When implemented together, it is expected that pollutants discharged into receiving water bodies
will be reduced to the maximum extent practicable.
Total Progress to Date:
Estimated Nutrient Reductions: 26.14 lbs/day TN; 7.32 lbs/day TP
Estimated Progress to Date Implementation Cost: $20,855,707 (Street sweeping, stream
bank restoration and regenerative step pool system costs not included)
Bacteria reductions
Bacteria survival is dependent on soil moisture, temperature, pH, availability of nutrients and
antagonistic organisms. Under ideal conditions, the bacteria is retained near the soil surface long
enough for infiltration of water into unsaturated soil to occur, resulting in bacteria die off within
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the first two feet. Under less than ideal conditions, best management practices (BMPs) are the
most effective and practical means of preventing or reducing bacteria from entering surface
waters.
BMPs reduce bacteria levels in many different ways. Non-structural BMPs are practices that
mainly control bacteria at the source; a few examples of these are proper cleanup of pet waste,
managing livestock manure, and routine septic inspections and pump-outs. Septic tanks should
be inspected every three years and pumped as needed, usually every three years or when the tank
is about 1/3 filled. By maintaining your septic system regularly, it is less likely to fail and
contaminate surface or ground water. It also extends the longevity of your septic system, saving
money for costly repairs or replacements.
Structural BMPs usually involve building a structure and may have a higher cost associated with
it. Examples include buffers, constructed wetlands, sand filters, infiltration trenches, low impact
development, and stream fencing. Dense vegetative buffers facilitate conventional bacteria
removal through detention, filtration by vegetation, and infiltration into soil.
Other methods of bacteria removal include the use of chemicals, such as chlorine, or the use of
ultraviolet lights. These methods can be costly and require considerable oversight. Table 7
illustrates typical bacterial reductions from commonly used BMPs.
Table 7 - Typical bacteria, suspended solids, and nutrient reduction from stormwater
best management practices
Total Total
Land Nitrogen Phosphorus Suspended Bacteria
Area % % Solids % Reduction
BMP Needed Cost Reduction Reduction Reduction %
Total Total
Land Nitrogen Phosphorus Suspended Bacteria
Area % % Solids % Reduction
BMP Needed Cost Reduction Reduction Reduction %
Buffer Strips Low Medium 20 - 60 20 - 60 20 - 80 43-57
Constructed
N/A N/A 20 45 60 78-90
Wetlands
Sand Filters N/A N/A 47 41 57 36-83
Dry Detention Pond High High 15 25 70
Infiltration Trenches Low Medium 45 - 70 50 - 75 75 - 99
Wet Ponds* Medium High 20 45 55-94 44-99
Biofiltration N/A N/A 25 34 >99
Bioswales Low Medium 25 34 70
Storm water
N/A N/A 30 49 N/A 78-90
wetlands
*if properly managed
The St Jones bacteria TMDL requires a 90% reduction in bacteria numbers. The State of
Delaware Surface Water Quality Standards, as amended July 11, 2004, provides specific numeric
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criteria for bacteria for the waters of the Christina Basin. The water quality standard for
enterococcus bacteria in the Christina Basin is as follows for primary contact recreation for fresh
waters:
• Single-sample value is 185 enterococcus colonies per 100 ml.
• The geometric mean of representative samples should not exceed 100 colonies per 100
ml.
The geometric mean enterococcus bacteria levels in the St Jones River are discussed in more
detail below.
400 Geometric mean of Enterococcus
Bacteria
300 St Jones Watershed
Enterococus (cfu/100 ml)
St. Jones at Bowers
200 Beach, mouth to
Del.Bay.
St. Jones River @
Barkers Landing
100
St. Jones River @ Rt.
10
Moores Lake @ S.
0 State St.
2000 2005 2010 2015
Year
Figure 3 - The year geometric mean of Entrococcus Bacteria in the St Jones River.
The levels of enterococcus bacteria in the St jones River have fluctuating levels with a mostly
decreasing trend across stations. Figure 3 shows the geometric mean enterococcus bacteria
levels in the River from 2001 to 2012.
Implementing these Pollution Control Strategies will result in continued reduction in bacteria
numbers. Only monitoring of the surface-water will clearly demonstrate the effectiveness of the
installed BMPS in reducing bacteria numbers.
Additional Progress Items
In 1986, the Silver Lake Commission (Commission) was formed following the recommendation
of Dover’s City Council. On August 27, 1990, by request from then-Mayor Jack Richter, the
Commission was officially adopted as an advisory committee to the City Council and City staff.
Since then, the Commission has worked to improve the condition of the Lake and provide a
forum for public involvement on issues related to the Lake. Commission members seek ways to
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improve the Lake’s water quality, wildlife habitat, open space and park opportunities, and water-
related activities through participation and coordination with other government bodies and
institutions.
The hard work of the Commission and its partners has paid off and can be verified by the amount
of progress that has been made within the last year. Some of the major accomplishments of the
Commission include:
• Silver Lake Park - Two successful planting events took place this past spring and fall of
2011 and one took place in the spring of 2012 that expanded the riparian buffer zone
around the St. Jones River in Silver Lake Park. Approximately 120 volunteers helped
plant shrubs and trees that will help improve water quality and protect the stream banks.
The plantings were a continuation of the Silver Lake Park Revitalization Project that was
initiated in 2007.
• Delaware Agricultural Museum – The mill pond has been enhanced and the old wind
mill is fully functional again. A buffer of native vegetation has been planted around the
mill pond to improve water quality and to limit Canada geese access to the pond. The
monitoring of bacteria levels in the pond hasdecreased since the buffer has been
planted.
• Mirror Lake – The Commission is working in conjunction with DNREC and the City of
Dover to move forward with the cleanup of Mirror Lake. A stormwater wetland will be
constructed in the near future to treat runoff from the DNREC and Treadway Tower
parking lots.
• Eroded channel behind the Ag Museum and Dover pools – A regenerative step pool
system will replace the highly eroded drainage channel that empties directly into Silver
Lake. The plunge pools will help collect sediment before it enters the Lake and a newly
constructed wetland at the foot of the channel will also help filter the water.
• Outreach material – Educational brochures have been developed for City of Dover
residents to educate the public about their impact on our local waterways.
• Rain garden planted at Fairview Elementary – Over 300 students from kindergarten
through fifth grade participated in planting over 200 native plants. The rain garden will
collect and filter runoff from the school’s roof and will also provide a unique garden for
teachers to utilize for outdoor learning activities.
Overall Nutrient Load Reduction Progress
All sectors to date have taken steps to improve water quality through the implementation of laws,
regulations, and voluntary BMPs. Analysis using a basic land use loading rate model shows that,
to date, nonpoint sources of Total Nitrogen and Total Phosphorus have been reduced by 34% and
151 % respectively from the TMDL baseline levels. While land use modeling based on current
practices predicts phosphorus reductions exceeding that required by the TMDL, there is still a
need for further reductions in nitrogen and areas that are currently lacking, such as wastewater
and stormwater. The total strategy implementation reductions and costs are discussed in more
detail in the section entitled, “Analysis for TMDL Achievement and Costs”.
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ST. JONES RIVER WATERSHED POLLUTION CONTROL STRATEGY
RECOMMENDATIONS
BROAD PURPOSE
Remediate the waters of the St. Jones to a condition that meets the standards of the Clean Water
Act (CWA). Once the water quality has improved to the necessary extent, the waters can be
removed from the 303d list.
SPECIFIC GOALS
Limit pollutants to levels at or below the Total Maximum Daily Load (TMDL) values specified
in the regulation; this entails an overall reduction of nitrogen and phosphorus in the waterways
by 40%. Nonpoint sources must reduce total nitrogen by 376.51 lbs per day and total
phosphorus by 47.62 lbs per day.
Table 8 - Load reduction needed based upon 2007 land use to achieve TMDL reduction of
40% for nitrogen and phosphorus
Load Reduction Nitrogen N (lbs/day) Phosphorus (lbs/day)
Stormwater-Current 26.14 7.32
Wastewater-Current 1.60 0.55
Agriculture-Current 95.33 64.03
Riparian Buffers – Current 0.02 0.01
Total – Current Practices 123.09 71.91
Stormwater - Future 13.57 0.66
Wastewater - Future 65.62 7.34
Agriculture - Future 166.22 26.07
Total – Current and Future 368.50 105.98
Practices
TMDL Target Reductions 367.51 47.62
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Strategy Periodization
The recommendations are organized by major categories (Open Space, Stormwater, Wastewater,
Agriculture, and Other) according to pollutant loads and nutrient reduction strategies. The
Tributary Action Team first recommendation was that there be a fully funded staff position to
coordinate watershed projects. The watershed coordinator responsibilities would be:
1. To develop an implementation strategy from the St Jones Watershed Implementation
Plan.
2. Determine what water quality projects are feasible from Implementation Plan based upon
water quality benefits, cost of installation and ability to implement project(s).
3. Work with Silver Lake Commission to create partnerships for water quality project(s).
4. Obtain funds for design and construction of water quality projects.
5. Work with City of Dover to plan and create a stormwater utility for watersheds within
City of Dover municipal boundaries.
6. To develop watershed educational materials.
The watershed coordinator was initially funded in 2007 through Delaware’s 319NPS program
and for the last three by a FY 2009 106/604(b) WORKPLAN Subobjective 2.2.1: Protect and
Improve Water Quality on a Watershed Basis, awarded to the Department of Natural Resources
and Environmental Control in October 2008. As part of that award, the U.S. Environmental
Protection Agency (EPA) has directed the Department to carry out planning functions and
implement projects which define, assess, and manage pollution entering State waters from
“nonpoint sources”.
Nutrient Reducing Recommendations
Nutrient Reducing Recommendation 1 – Riparian Buffers
A St. Jones watershed buffer overlay map should be developed to ensure buffers are in place
throughout the watershed. This overlay map should be developed in cooperation with local
municipalities, used to coordinate efforts among jurisdictions, and must consider urban
(developed) and rural (undeveloped) settings.
A 100-foot vegetated or forested riparian buffer zone should be required within the
watershed for all water bodies, except for those on agricultural lands. Measurement should
be taken from the edge of the bank of the water body landward.
Implementation Goal: Require 100 foot riparian buffer from top of bank.
Basis of Recommendation: Buffers help to filter nutrients and slow overland stormwater flow.
Kent County has issued several ordinances related to development and buffers, including an
ordinance requiring 100-foot setbacks from blue line streams and tax ditches, and a 25-foot
buffer/setback for wetlands. However, the County setbacks are not required to be vegetated.
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The City of Dover has an ordinance that requires all buildings, structures, and impervious
surfaces to be set back at least 100 feet from the top of bank from wetlands greater than 0.25
acres in size and from all water bodies. The setback can be reduced provided a riparian buffer is
established in the setback. The setback can be further reduced to 30 feet provided the riparian
buffer planted in native vegetation and bank stabilization is implemented through the planting of
native species. For single family residential use the setback sets may be reduced to 75 feet. The
ordinance allows small (less than 200 square feet) stairs, ramps, open decks, patios, or docks to
be placed within setback if they are necessary for access to natural features. These ordinances
were approved as of November 2010. Figure 4 shows these areas that would be protected under
this ordinance and the Kent County’s buffer requirements.
Figure 4 - Streams (outline in green) within Dover that require riparian buffers
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The St. Jones Tributary Action Team feels these ordinances (Table 9) may not be strong enough
as written to adequately protect the waters of the St. Jones River watershed. Recommendations
are being made to strengthen and supplement County and municipal ordinances.
Table 9 - Kent County Ordinance (187-78) and the City of Dover required setbacks from
water bodies
Planting
Waterbody type Distance in feet Requirements
required
No Buildings, structures,
100 from shoreline paved surfaces, except
Kent County --Tidal (as defined by mean stairs , ramps, patios, or No
high-water line) docks less than 200
square feet
100 from top of
City of Dover- Tidal Same as above No*
bank
Kent County-Non-tidal 100 from shoreline
freshwater body, lake, pond or as defined by mean Same as above No
“blue –line stream” high-water line
City of Dover- wetlands and 100 from top of
Same as above No*
all water bodies bank
Kent- County -Any non-blue 50 from shoreline
Same as above No
line stream, creek or ditch or top of bank
Requires preservation or
Kent County -Any TMDL 100 from center May be
reestablishment of
promulgated basin line of stream required
riparian buffer
City of Dover – No TMDL
NA NA NA
requirement
* Setback be reduced if riparian is planted with native vegetation and bank is stabilized
through planting of native vegetation.
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Figure 5 shows the area that would be protected by modifying setback by means of Kent County
Ordinance §187.
Figure 5 - Riparian Buffers in the St. Jones Watershed
The County setbacks are not required to be vegetated except in some cases for TMDL
watersheds. Based upon the Tributary Action Team’s recommendations, DNREC is
recommending that the County strengthen and supplement County requirements with the
expectation that these measures will protect and improve water quality and the quality of life for
the residents in the watershed.
From the Team’s recommendations, DNREC performed GIS analyses using ESRI’s ArcGIS
software on the 2007 National Hydrologic Data Set from U.S. Geological Survey (USGS) and
Delaware Statewide Wetlands Mapping Project state wetlands maps (SWMP). Using these tools,
DNREC was able to compare the current and proposed setback and buffer protection measures
for all waterbody types, including TMDL and non-TMDL waters, as well as identify vulnerable
areas that require additional protection.
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In the first GIS analysis, perennial and intermittent streams were delineated using the Hydrologic
Data Set, and 100 and 50 foot buffers were applied respectively either from the center line of the
stream for TMDL watersheds, or from the mean high water line, shoreline and/or top of bank for
non-TMDL watersheds. To improve consistency, however, the outer limits of delineated tidal or
freshwater wetlands served as the starting point to apply the appropriate buffer distances for non-
TMDL watersheds. Providing the same buffer starting point for both TMDL and non-TMDL
watersheds presents the data in a format conducive for comparisons.
A second GIS analysis was conducted where the buffers were applied from edge of the wetland
associated with the perennial and intermittent streams. The City of Dover’s ordinance is similar
to Kent County’s, except the TMDL streams in Dover are not required to have setback as
required in Kent County’s ordinance; A 100 foot buffer was applied to perennial streams from
top of bank (i.e. edge of wetland) and 50 feet from top of bank of the intermittent streams to
mimic Kent County setback requirements (ordinance 187-78) for non-TMDL and the City of
Dover set back ordinances. Acreage of the buffers from each GIS analysis was determined so
that comparison could be made between riparian buffering schemes.
Table 10 - Acreage included in setback by means of Kent County Ordinance §187-78 or
protected by §187-77*
Setback Distance Type Acreage Additional acres Total acres
in feet included in protected by protected
required wetlands ordinance resulting from
County 187-77* current County
setback ordinances
187-78 187-77, 187-78
Any TMDL 100 from Perennial 3668 6436 10104
promulgated center line
watershed of stream
Any TMDL 100 from Intermittent 931 0 931
promulgated center line
watershed of stream
Non-TMDL 100 from Perennial 2689 6436 9125
watershed shore line fresh and/or
or mean- tidal waters
high line
Non-TMDL 50 from intermittent 1152 1260 2412
watershed shore or stream or
top of ditch
bank
* As per ordinance § 187-77, Kent County does not allow subdivision, filling, developing or
clearing of vegetation in wetlands unless granted permission by a regulating agency.
The GIS analysis showed that by applying the non-TMDL water setbacks to all perennial and
intermittent streams within the St. Jones watershed, an additional 502 acres of buffers would be
provided. These acres would protect the streams in the St. Jones watershed and increase the
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water quality benefits for the entire watershed. DNREC believes that the current County’s
TMDL setback ordinance for watersheds does not provide adequate water quality protection to
the streams. In most cases, streams are bordered by wetlands without buffers to protect them
from adjacent uplands; upland sources are a primary contributor of nutrients and bacteria found
in these waters. It must be noted this scenario assumes that all lands adjacent to perennial and
intermittent streams were developed, but this would most likely not occur in the St. Jones
watershed under current County and municipalities zoning ordinances but some development
will occur.
Research has shown that for each acre of grass, shrub, or tree buffer, two upland acres and its
excess nutrients and bacteria are removed from the surrounding area. If the County ordinance
for non-TMDL waters was applied to TMDL waters in the St. Jones watershed, so that the
setback was applied at the mean high tide line for tidal waters and the top of bank for non-tidal
waters, an additional 502 acres of buffer would protect the water quality in these waterways.
The proposed recommendation would offer protection for a portion of existing forested riparian
buffer that is currently at-risk of being developed under current County and municipal setback
requirements. The recommendation would allow inadequate buffers to be reestablished so that
they can fully provide water quality treatment benefits. Developers should be required to protect
existing, or provide new buffers when necessary, as community open space; however, the
responsibility for buffer maintenance will fall to civic and homeowners associations or
maintenance corporations rather than individual homeowners. Buffers should be planted and
designed to require minimal maintenance. In addition, buffers should be planted with native
species in an effort to ease maintenance, reduce erosion, and increase nutrient uptake
capabilities. The developer should also guarantee all trees planted in the development remain
living for the first year, or offer replacement plants as individuals are lost.
From the GIS analyses and Tributary Action Team recommendations, DNREC proposes that a
100 foot vegetated buffer be applied to all perennial streams from either top of bank or the mean
high-tide line based on tidal properties, and 50 feet from top of bank for intermittent streams
within the St. Jones watershed. This would mimic Kent County’s current ordinance 187-78 for
non-TMDL waters, except the setback (buffer) would need to be planted in native vegetation.
As applied, the County’s TMDL ordinance is less protective than its non-TMDL setback
requirements.
Implementation Schedule: City of Dover adopted riparian ordinance in November 2010 and
Kent County has proposed a new buffer ordinance in 2012.
Expected Reduction: For each acre of 100 feet wide buffer installed, 0.004 lbs per day of TP
and 0.18 lbs per day of TN would be reduced.
Cost: Estimated at $115,000. Developers should be required to protect existing and/or provide
new buffers if necessary as community open space; however, the responsibility for buffer
maintenance will fall to civic and homeowners associations or maintenance corporations, not
individual homeowners. Buffers should be planted and designed to require zero or minimal
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maintenance. The developer must also guarantee all trees planted in the development for the first
year.
Potential Funding Sources: Funding would come from developers.
Action Needed: The Department will work with Kent County and other municipalities within
the watershed to develop buffer regulations that will be consistent with existing ordinances.
Also, the Team recommends that Kent County Conservation District (KCD) have the authority to
enforce buffer compliance. DNREC will initiate discussions with KCD about this
recommendation, and note the possibility of linking the buffer compliance with the
recommended implementation of a stormwater utility.
Nutrient Reducing Recommendation 2 – Open Space
Land maintained as passive or active open space under local ordinances or codes should be
managed to minimize nutrient loading.
Implementation Goal: Encourage the planting of open space in native vegetation and require
compliance of Nutrient Management Act for parcels greater than 10 acres.
Basis of Recommendation: The St. Jones watershed has the highest population of all the
watersheds in Kent County, likely due to the high number of economic opportunities in the state
capital of Dover. In the past ten years, drastic land changes have taken place in the watershed. Urban
and residential land uses have increased by 6.4% in the watershed and agricultural and forested land
uses have decreased by 6.4% and 1.40%, respectively. Along with these changes, the amount of
impervious surface in the watershed grew as more rural land was converted to urban uses. Currently,
the St. Jones watershed has impervious cover well over 13%. As a result of the higher area of
impervious cover and increased urbanization, surface water pollution has become an issue throughout
the watershed.
Open space can have many valuable functions and should include natural areas such as wetland
restoration areas and buffers. Open space should be planted with appropriate native vegetation
and protected though easements. In impaired watersheds, water quality protection must be a
priority when developers design open space; more emphasis placed on water quality leads to
lower nutrient loads. Keeping some of the developing area as open space also helps to reduce
nutrient loads. Kent County subdivision ordinances have established protection and planting
standards for woodlands, and have restricted subdivision and/or clearing under the jurisdiction of
United Sates Army Corps of Engineers. In addition, Kent County considers lakes, ponds, and
streams as permanent open space.
The City of Dover has drafted environmental protection ordinances to protect public health and
safety by ensuring that environmental standards for water, air, and soil in Dover are adequately
addressed. The City’s intent is to protect environmentally sensitive land as well as the plants and
animals that reside on that land. Dover included all land areas that contain one of the following
natural features that shall be considered to be an environmentally sensitive area or an area of
scarce resources subject to specific requirements for environmental protection and conservation:
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flood hazard areas, steep slopes, water bodies and wetlands, wet soils, woodlands, significant
wildlife habitats, prime agricultural soils, and designated scenic areas.
Every five years the municipalities in Delaware must review their comprehensive management
plans but must be updated every 10 years. Camden, Wyoming and Cheswold are working on
their comprehensive management plans. Dover has revised its plan. During 146th legislative
session, the General Assembly changed the Act (Senate Bill 138 w. SA 1, An Act to Amend
Title 9 Relating to Comprehensive Land Use Plans) that required County governments to review
and update their comprehensive plans every five to be updated every 10 years, which is the same
presently required for municipalities in the state. DNREC reviews these plans through the
State’s Preliminary Land Use Service (PLUS) and recommendations are made to improve the
protection of the natural resources within their municipal boundaries.
The Delaware Nutrient Management Commission (DNMC) is the controlling authority for
fertilizer application on parcels of land greater or equal to 10 acres within the State based upon
the Nutrient Management Act promulgated in 2000. The Nutrient Management Act requires
nutrient applicators to be certified. Requiring applicators to log the amount of nutrients they are
applying will help to track the amount of nutrients being applied to individual non-agricultural
properties. The DMNC has also recognized that significant contributions of nitrogen and
phosphorous come from land parcels less than 10 acres in size. In response to this knowledge,
the DNMC has produced brochures on proper lawn maintenance. These brochures have been
placed in most retail outlets that sell fertilizer in the watershed. In addition, a public service
advertisement was broadcast on WBOC television station reminding people about proper lawn
nutrient application and urging people to get a soil test done prior to applying fertilizer. Lawn
care companies must be in compliance with the Nutrient Management Act requirement for turf
management.
Implementation Schedule: Will work with the county and other municipalities to create
ordinances.
Expected Reduction: For each acre of open space that is converted from agricultural land,
0.0068lbs/day of TP could be reduced, and.048 lbs/ day of TN could be reduced.
Cost: There is no additional cost for implementing Recommendation 2 because open space is
required by existing municipal and county ordinances. There is a cost to enforce the ordinances;
however, most of the cost is absorbed by the development community.
Potential Funding Source: Cost is first absorbed by the developer of the project, and then
passed on to the new property owner.
Action Needed: DNREC will work with the Department of Agriculture about promulgating
regulations prohibiting the application of nutrients to open space unless prescribed by a nutrient
management plan and will work with the County and municipalities to implement. The
Department also requests communities to follow the Helping the Environment Starts in Your
Back Yard which was developed by the Department’s Coastal Program to restore, manage and
maintain open space.
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Nutrient Reducing Recommendation 3 – Open Space Education
Homeowners’ association members and homeowners should be educated on caring for open
space in their neighborhoods and caring for their backyards to minimize nutrient loading and
encourage natural habitat.
Implementation Goal: Develop an education program for caring for open space maintenance
and backyard conservation.
Basis of Recommendation: Based on 2007 land use data, a significant portion of the St. Jones
watershed is urban (33.3 percent) and much of it is turf. Over 73,000 acres of residential turf
exists in Delaware and 58 percent of it is fertilized, usually without having a soil test indicating
the need for fertilization.
It is apparent from the data set below that the non-farm fertilizer tonnage has grown significantly
since 1995 to 2008. Correspondingly, there has been an eight percent increase in urban acreage
over this time period suggesting that fertilizer applications to other land uses, such as residential
lawns, is increasing. Sims et al. 1 (2007) reported that from 2000 to 2006, 50%, 30%, and 20%
of the non-farm N fertilizer and 44%, 32%, and 24% of the non-farm P fertilizer was used in
New Castle, Kent, and Sussex County, respectively.
Figure 6 - Percentage of Non-Farm Fertilizer Sold in Delaware by Year
(Source: Jones, Lyle and Volk Jennifer. 2008. Effect of Delaware’s Nutrient Management Law On Nutrients Sold in Delaware
and Its Apparent Impact on Nitrogen and Phosphorus Total Maximum Daily Loads ---- Another Perspective.)
1
Sims, J.T., J. McGrath, and A.L. Shober. 2007. Nutrient Mass Balances for the State of Delaware: Final Project Report,
Submitted to the Delaware Nutrient Management Commission. University of Delaware, Newark, DE.
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In response to the needs outlined in the St. Jones Implementation Plan, the St. Jones watershed
Coordinator proposes to launch an educational/outreach campaign in the St. Jones watershed in
an effort to change watershed residents’ lawn care practices. The St. Jones watershed
Coordinator, along with project partners, believes that by figuring out the real reasons people
over-fertilize, they can cause the necessary behavior changes to reduce nutrient runoff from
lawns in the watershed. They are doing this by helping to develop the Delaware Livable Lawns
Program. The Livable Lawns Program certifies lawn care companies that follow
environmentally-friendly practices in fertilizer application while educating homeowners. While
many homeowners may be unaware of where, when, and how much fertilizer to apply,
professional lawn care staff have the expertise to fertilize lawns correctly. Certified Livable
Lawns companies go a step beyond the current regulations that govern fertilizer use by following
environmentally-friendly practices resulting in healthy lawns and healthy water. In addition, the
Livable Lawns program is beginning a residential education portion to educate homeowners as to
their responsibility when it comes to fertilizer application and how what they do on their lawns
can affect us all.
The Delaware Livable Lawns Program is administered by the Delaware Nursery & Landscape
Association (DNLA). The DNLA is a non-profit trade organization serving Delaware's
horticultural related businesses and the companies that supply them. The DNLA's mission is to
advance the common interests of its members and to promote the use, and enhance the quality, of
the products and skills of the green industry. The DNLA also works in cooperation with the
Delaware Department of Agriculture and Delaware Cooperative Extension to shape legislative
and administrative policies and procedures on matters that are of interest to Delaware's Green
Industry.
The Delaware Livable Lawns Program Advisory Group was developed through a cooperative
effort of:
• Delaware Department of Transportation
• Delaware Department of Natural Resources & Environmental Control
• Appoquinimink River Association
• Delaware Department of Agriculture Nutrient Management Commission
• New Castle Conservation District
• US Department of Agriculture Natural Resources Conservation Service
• University of Delaware Institute for Public Administration Water Resources Agency
• University of Delaware Cooperative Extension
• Delaware Grounds Management Association
• Delaware Nursery & Landscape Association
At no cost to participants, the Smartyards Program provides official certification for properties
where owners meet the four criteria necessary for wildlife habitat: food, cover, water, and places
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for wildlife to raise young. Certified habitats may range from those meeting the minimum
requirements, such as a small urban balcony or rooftop, to extensive naturalized areas that meet a
variety of wildlife needs. By adopting practices beneficial to wildlife such as planting native
species, limiting use of chemical fertilizers and pesticides, reducing the size of lawn areas, and
better maintaining small areas of forest or wetlands if located in backyards, participants help to
improve local water quality. Smartyards provide habitat for a greater diversity of wildlife
species, prevent the pollution of runoff from urban and suburban yards, and reduce the quantity
of runoff more than traditional turf grass landscapes. Participants begin to make the connection
that the wildlife in their yards is a part of the natural environment of their community, which
includes the St. Jones River and its tributaries. The Watershed Coordinator has received some
interest in this program in Dover and wants to implement it in the St. Jones in 2012.
In late 2005, the Delaware Coastal Program produced Community Spaces, Natural Places which
is a guide to restoration, management and maintenance of community open spaces. The guide
provides communities and landowners with a basic understanding of low cost natural habitat
options for community open space and was designed to provide practical approaches for open
space management, challenges, and opportunities of mobilizing a community open space as well
as low cost natural habitat options for open space.
Expected Reduction: 0.11 of N and 0.04 lb per acre lot of P for Smartyard landscaping
Cost: The average cost of installing Smartyard landscaping in residential lawns in the
Appoquinimink watershed has been $956.20 per ¼-acre yard. This is an average of the total
costs of 20 projects in the fall of 2004 and 20 projects in spring of 2005. Therefore, based on
this initial cost, the cost of the nutrient reductions is $34,933/lb N and $95,272/lb P on an annual
basis. These high costs are obviously excessive per pound of nutrients reduced because of the
first year’s cost of installation, staff time and educational materials. The annual maintenance and
operation costs will undoubtedly be a small fraction of the original installation cost, so the
nutrient reduction cost should decrease considerably in successive years.
Cost of the Liveable Lawns program was $40,000 for the first year and will be $25,000 each
year thereafter.
Implementation Schedule: Liveable Lawns program started in January 2011.
Expected Reduction: For Smartyards 0.11 of N and 0.04 lbs per acre lot of P for Smartyard
landscaping and but EPA considers urban stormwater runoff from yards, streets, parking lots
and other areas to be one of the most significant of contamination in our county’s waters.
Potential Funding Source: Program was funded through DelDOT initially. The Department
will work with partners including the County and local governments to apply for grants for this
work.
Action Needed: The Department will work with the Delaware Nursery and Landscape
Association and the Delaware Nutrient Management Commission to accomplish this
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recommendation and will work with other partners including the County and local governments
to accomplish this recommendation.
Nutrient Reducing Recommendation 4 – Sewer Repair
Sewer transmission systems should be repaired to reduce infiltration and inflow during wet
periods.
Implementation Goal: Reduce inflow and infiltration into Kent County Sewer system.
Basis of Recommendation: Based upon information provided to the Team from Kent County’s
wastewater treatment facility, flow to the county wastewater treatment plant may double during
rain events and nutrient loads may increase from more runoff. It is estimated that Dover
residents are paying at least $100,000 a year just to treat rainwater that has infiltrated into
Dover’s collection system. In the fall of 2006, Dover contracted with Video Pipe Services of
Beltsville, Maryland to determine areas where the sewer collection system needs repairs in order
to eliminate infiltration. From the information collected from this action, the City of Dover
estimated that over 700,000 gallons of rain water was eliminated from infiltrating and inflowing
during wet periods into their collection system. This estimated inflow resulted from 27 homes in
old Dover. The video of the collection system and subsequent smoke testing showed that most
of the infiltration came from roof downspouts being connected to the wastewater collection
system in old Dover area of the City. The City requested that each of the 27 home owners have
their downspouts disconnected from their below grade drain pipes which connected to sewer
system and requested the downspouts be allowed to flow on to the ground. The City re-checked
each home to see if the disconnection was completed. As of November 2012 over 60 homes
have had their down spouts disconnected from the sewer and the City is in the process of relining
sewer mains to reduce inflow and infiltration of rainwater.
Implementation Schedule: On going process.
Expected Reduction: Reduction of 2.9 lbs/day of P and 35 lbs/day of N from rain water
inflowing from 27 homes.
Cost: The City of Harrington estimated $400,000 to fix leaky sewer pipes that are letting
rainwater into the town’s sewer system.
Potential Funding Source: Sewer fees from customers of Kent County Wastewater Treatment
Facility and from City of Harrington.
Action Needed: None.
Nutrient Reducing Recommendation 5– Septic Pump Out and Inspection
Onsite Wastewater Treatment and Disposal Systems (OWTDSs) should be inspected and
pumped out regularly to reduce nutrient loading of the groundwater. Compliance with current
regulations should be promoted.
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Implementation Goal: Have all systems within the watershed inspected once every three years.
Basis of Recommendation: Currently septic permits require that the systems be pumped out
every three years or when the system contains 30 percent or more of solids. The County and/or
Department should institute a program that enforces the inspection and pump-out requirement for
onsite septic systems. A notification system should be developed such that homeowners would
be notified of this requirement in the year their system is due to be inspected. The County and
State should use computer software to track the occurrence of inspections and cooperate to
ensure compliance with regulations. The program should assist residents who have not had their
septic pumped in the previous two years to have their system pumped and inspected. The State
and County should subsidize the cost of inspections and pump outs. Following the inspection, the
inspector should provide the homeowner/resident with educational materials and receipt of pump
out.
Additionally, the Department has the authority to regulate OSWDS. On July 11, 2003 the
Governor signed House Bill 150 into law, which authorized the Department to establish a license
for persons who inspect systems and other OWTDS, and set an annual license fee for septic
system designers, installers, site evaluators, liquid waste haulers, inspectors and percolation
testers, similar to other license fees charged by the Department. On January 1, 2006, DNREC
developed and implemented Class H licenses for a septic system inspectors. Following the
inspection, the inspector provides the homeowner/resident with educational materials and receipt
of pump out.
With the promulgation of new proposed Regulations Governing the Design, Installation, and
Operation of On-site Wastewater Treatment and Disposal Systems by the end of 2012, the
Department believes that inspected and pumped out on-site wastewater treatment and disposal
systems will occur more regularly. The proposed regulations require that a septic system to be
inspected when the parcel is sold. If the new regulations are not promulgated as anticipated, the
Department will promulgate the necessary regulations for this recommendation.
The watershed currently has 6,244 OSWD systems within its boundaries. If all systems are
pumped once every three years, as required by state regulations, [14] then 2,081systems would be
pumped annually. The soils in the watershed are mostly well drained so the actual TP reduction
will likely be significantly less. Each system pumped out would reduce TP and TN surface
and/or groundwater load by 0.6 lbs/system/year and1.6 lbs/system/year, respectively.
Implementation Schedule: New regulations will be promulgated by 2012.
Expected Reduction: 5.69 lbs/day of TP and 14.2 lbs/day of TN for pumping out 2,081 septic
tanks
Cost: The costs of the inspection will be covered through an agreement between the buyer and
the seller. The cost of pumping out OWTDS ranges from $185-200 per system, with an average
[14]
Regulations Governing the Design, Installation and Operation of On-Site Wastewater Treatment and
Disposal Systems, adopted March 11, 2002.
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cost of $192.50 per system (DNREC Small Systems Branch, personal communication, 2007).
Permit conditions require that septic systems be pumped once every three years, which
capitalizes this figure to $68.60/system/year. The proposed inspection will be performed at an
estimated cost that range from $200 to $400 with an average cost of $300 at the time of pump-
out (DNREC Small Systems Branch, personal communication, 2007). Thus, the inspection fee
will only be incurred once every three years, so that annually it equates to $100. The total cost
of the OWTDS inspection and compliance program will cost the system owner
$169/system/year.
Potential Funding Sources: The cost of these systems will be paid by the land owner. Cost
share funds may be found to assist those of middle income and below. At present, State
Revolving Fund (SRF) money and Septic Rehabilitation Loan Program funds may be used to
provide low interest loans to property owners that need to replace or repair a failing system.
Action Needed: With the promulgation of the new proposed Regulations Governing the Design,
Installation, and Operation of On-site Wastewater Treatment and Disposal System by the end of
2012, the Department believes that Nutrient Reducing Recommendation 5 for inspections of
individual onsite wastewater treatment and disposal systems (OSWDS) will occur at the time of
sale and at least once every three years. If the new on-site wastewater treatment and disposal
system regulations are not promulgated as anticipated, the Department will promulgate the
necessary regulations for this recommendation.
Nutrient Reducing Recommendation 6 – Cesspools and Seepage Pits
Cesspools and seepage pits should be eliminated systematically as these wastewater systems
discharge nutrients and bacteria directly into the groundwater. The septic inspection and
maintenance program should help locate and eliminate them.
Implementation Goal: Eliminate all cesspools and seepage pits in the watershed.
Basis for Recommendation: The DNREC Watershed Assessment Section estimates that there
are at least 30 cesspools [15] and/or seepage pits in the St. Jones watershed, however that
estimation may be low. Any existing cesspools would likely be with old farmsteads and very old
mobile home parks.
Implementation Schedule: New regulations will be promulgated by 2012.
Expected Reduction: 0.6 lbs/day of TP and 0.16 lbs/day of TN for 30 cesspools
Cost: The cost depends on the number of systems that need replacement and the types of
systems that would be permitted in their place.
[15]
This number was determined by using a GIS and old aerial photographs to assess large parcels over 10 acres
within the Murderkill Watershed with the assumption that large parcels were farmsteads and had a dwelling unit and
cesspool.
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Potential Funding Source: The cost of these systems upgrades will be paid by the land owner.
Cost-share funds may be available to assist those of middle-income and below. At present, State
Revolving Fund (SRF) money and Septic Rehabilitation Loan Program funds may be used to
provide low interest loans to property owners that need to replace a failing system.
Action Needed: With the promulgation of the new proposed Regulations Governing the Design,
Installation, and Operation of On-site Wastewater Treatment and Disposal Systems in 2012, the
Department believes that Nutrient Reducing Recommendation 6, which details the systematic
elimination of cesspools and seepage pits as the properties are transferred from one owner to
another. If the new on-site wastewater treatment and disposal system regulations are not
promulgated as anticipated, the Department will promulgate the necessary regulations for this
recommendation.
Nutrient Reducing Recommendation 7 – Septic Removal
If it is physically and legally available (as defined by the Regulations Governing the Design,
Installation and Operation of OWTDSs), OWTDSs should be removed in growth zones and
connected to the Kent County Wastewater Treatment Facility. The inspection and
maintenance program will identify the connection of failed systems to sewer systems, if
available, or replacement systems, if not.
Implementation Goal: Eliminate failing septic systems by connecting them to Kent County
Wastewater Treatment Plant.
Basis for Recommendation: In Delaware, surface and ground water are directly connected.
Consequently, impacts on groundwater will impact the quality of the surface water. In the
summer, surface water flow is primarily groundwater seepage into the stream. Nutrients from
onsite wastewater treatment and disposal systems will reach the surface water through the
groundwater.
With the promulgation of the new proposed Regulations Governing the Design, Installation, and
Operation of On-site Wastewater Treatment and Disposal Systems by the end of 2012, DNREC
believes that Nutrient Reducing Recommendation 7 will be met. If the new regulations are not
promulgated as anticipated, the Department will promulgate the necessary regulations for this
recommendation.
St. Jones watershed is estimated to have 918 residents that with be connected to Kent County
Treatment Facility over the next 15 years. Many of these systems are old and are
malfunctioning.
Implementation Schedule: To be completed by 2027.
Expected Reduction: 0.11 lbs/day of TP, and 3.44 lbs/day of TN for 61 system per year
Cost: Kent County charges a capital impact fee of $1,679 and a sewer district impact fee of
$1,491 for each home or equivalent dwelling unit. There is also an $85 permit fee required by
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the County. Total cost to connect to county sewer is $3,255 but this does not include the actual
cost to run the sewer pipe into the county sewer line.
Potential Funding Source: As areas are being developed by private entities, the developers will
absorb some of the septic elimination cost.
Action Needed: Assist the county by identifying areas that have a large number of failing old
wastewater treatment and disposal systems due to system age and undersized disposal areas.
Nutrient Reducing Recommendation 8 – Performance Standards
All new and replacement onsite wastewater disposal systems must be designed to achieve
performance standards using the best available “new technology” to achieve required nutrient
reduction targets for the watershed.
Implementation Goal: Require all new onsite wastewater treatment and disposal systems to
meet TMDL nitrogen reductions.
Basis for Recommendation: In response to the TMDL, Kent County requires that new
individual residential, large, or community onsite sewage treatment and disposal systems sited in
a watershed with an established Total Maximum Daily Load (TMDL) shall be designed and
installed in accordance with the nutrient load reductions prescribed by the TMDL or they shall
use the best available technologies in order to achieve the required nutrient reduction targets set
for the particular watershed (See Chapter 187, Subdivision and Land Development (Adopted
June 24, 2003)).
The DNREC Ground Water Discharges Section and the Watershed Assessment Section
contracted with Dr. Mike Hoover with the University of North Carolina to develop and
recommend performance standards for all sizes of onsite systems. Technologies are available to
reduce the nutrients in OWTDS effluent and are defined by the following performance standards:
Performance Standard Nitrogen level 1 (PSN1) to achieve 5 mg/l at the end-of-pipe of the
pretreatment unit; PSN2 10 mg/l at the end-of-pipe of the pretreatment unit; PSN3 20 mg/l at the
end-of-pipe of the pretreatment unit; PSP1 4 mg/l at the end-of-pipe of the pretreatment unit;
PSP2 8 mg/l at the end-of-pipe of the pretreatment unit.
Because of this work, the permit applicant can select an approved technology from a list
maintained by the Ground Water Discharges Section. Since alternative systems are more
expensive than standard systems, the Department wants to ensure that they are functioning in
order to ensure the nutrient reductions and protect the investment, and therefore will require a
service contract with a certified service provider.
In addition, new homebuyers may not understand the functioning of their system or the impacts a
failing system could have on the environment. Therefore, by providing education materials, the
homeowner may prevent long-term problems and save money.
Implementation Schedule: Will be implemented with adoption of new regulations in 2012.
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Expected Reduction: A total of 210 septic systems were pumped out and inspected in Sussex
County, and seventy percent were in satisfactory condition. So, there was a 30% failure rate. If
this rate was applied to the St. Jones watershed, there would be a potential of 1,809 failed septic
systems within the watershed, and of these 1,809 failing system, 61 would be connected to
county sewer. Because Kent County ‘s Chapter 187, Subdivision and Land Development
(Adopted June 24, 2003) only requires new systems to meet TMDL reductions, no reductions in
nutrients would occur with this part of the recommendation unless the system was to connect to
county sewer.
As existing systems less than 2,500 gpd fail and require replacement, PSN3 will be required by
the revised state Regulations Governing the Design, Installation, and Operation of Onsite
Wastewater Disposal Systems and will result in a reduction up to 10.6 pounds of nitrogen per
year per system.
Cost: DNREC’s Small Systems Branch (personal communication, 2006) revealed that the
installation of best available technologies (BATs) to existing small (<2,500 gallon per day (gpd))
OWTDSs for advanced nitrogen removal would cost between $3,500 and $6,000 per system with
an average of $4,750. These technologies require a service contract by a certified service
provider with an estimated annual cost that ranges from $150 to $300, with an average cost of
$225/system/year. In addition, the systems will still require pump-outs, which cost
$64/system/year (DNREC small System Branch, personal communication, 2007), and will need
periodic mechanical parts repaired, estimated to cost $50/system/year and the electric cost of
running the system is likely to also cost about $50/system/year (DNREC Financial Assistance
Branch, personal communication, 2007). Costs are not currently available for the retrofit of
larger systems.
The cost of these systems will be paid by the landowner. Cost-share funds may be found to
assist those of middle income and below. At present, State Revolving Fund (SRF) money and
Septic Rehabilitation Loan Program funds may be used to provide low interest loans to property
owners that need to replace a failing system.
Potential Funding Source: The cost of these systems will be paid by the land owner. Cost-
share funds may be found to assist those of middle income and below. At present, State
Revolving Fund (SRF) money and the Septic Rehabilitation Loan Program provide low interest
financing for replacing failing septic systems and cesspools with on-site wastewater disposal
systems that will function in an environmentally sound and cost effective manner. The loan is
secured by a mortgage lien on the rehabilitated property. This program is managed by the
Financial Assistance Branch with technical assistance from the Ground Water Discharges
Branch. The Financial Assistance Branch shares a partnership with First State Community
Action Agency (FSCAA), who has program specialists in Georgetown and Dover to assist with
the application process.
Action Needed: With the promulgation of the new proposed Regulations Governing the Design,
Installation, and Operation of On-site Wastewater Treatment and Disposal Systems by the end of
2012, the Department believes that this recommendation on performance standards will be met.
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If the new regulations are not promulgated as anticipated, the Department will promulgate the
necessary regulations for this recommendation.
Nutrient Reducing Recommendation 9 – Stormwater Utility
A stormwater utility should be implemented to generate a stable source of funding for
stormwater management within the watershed.
Implementation Goal: Institute a stormwater utility in Kent County and within Dover.
Basis of Recommendation: Governor Minner’s Task Force on Surface Water Management
quantified the statewide financial need for stormwater management. The Finance Subcommittee
identified stormwater capital requirements of $207.3 million over the next five years and
projected annual maintenance requirements of $13.73 million (DNREC, 2005). The Task Force
recommended that a stormwater utility operating at the county or local level should be formed as
a funding vehicle for the purpose of providing a simplified and comprehensive approach to
drainage and flooding problems. A stormwater utility is an approach that can generate a stable
source of funding for stormwater management within the region. The funds are made available
by collecting user fees. Stormwater utility fees are generally set by the amount of impervious
cover on each resident’s property; the higher the impervious cover the higher the fee. GIS
mapping will be utilized to measure impervious surface generated by residential and commercial
development, and the utility fee will be charged based on the property’s Equivalent Runoff Unit
(ERU).
Level of Service analysis began in May of 2008 and was funded equally by the Delaware
Department of Natural Resources and Environmental Control (DNREC) Division of Soil and
Water Conservation, the Kent Conservation District, and Kent County. Representatives from
these agencies oversaw its preparation as the Joint Coordinating Committee (JCC). The
purposes of the project were to determine the current level and costs of surface water
management offered in Kent County and to identify the levels and costs needed to adequately
meet the needs of current residents and the expanding population. This analysis built upon
previous efforts such as Governor Minner’s Task Force on Surface Water Management (2005)
and the Delaware Public Policy Institute Dialogue on Financing Wastewater and Stormwater
Infrastructure (2006). In addition to the sponsoring agencies, meetings were also held with
numerous other government entities and stakeholders including DelDOT, tax ditch managers,
municipal representatives, the Home Builders Association of Delaware, and the Kent County
Conservancy.
This Level of Service analysis offered several recommendations on stormwater management
through creating a stormwater management district and developing mechanisms governing the
maintenance of privately-owned stormwater management structures. Level of Service Analysis
provided a framework for budgetary conversations and guidance for moving forward. It is not an
end point but rather a blueprint for future actions.
One challenge for the City of Dover to establish a storm water utility within its borders is that the
City is not a delegated agency for stormwater management. Thus, the City would need to
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become a delegated agency, which would include developing a fee schedule and staffing plan to
accomplish this. Additionally, any proposal that includes additional fees will likely not gain any
traction until the economy turns around.
Implementation Schedule: No date has been set.
Expected Reduction: Nutrient reductions cannot be assigned to this recommendation as it is a
mechanism for funding practices, not for implementing practice.
Cost: DNREC, Kent County, and KCD requested a level of service analysis and investigation of
the stormwater service district. URS, Inc. received the contract for the analysis, which costs
$75,000.
Potential Funding Source: Kent County and City of Dover
Action Needed: The Department will assist the County and/or Dover to implement a
stormwater utility in their jurisdictions.
Nutrient Reducing Recommendation 10 – Stormwater Best Management
Practices
Stormwater Best Management Practices (BMPs) should be designed to reduce nutrients
according to TMDLs.
Implementation Goal: Implement the new proposed Delaware Sediment and Stormwater
Regulations.
Basis of Recommendation: The Delaware Sediment and Stormwater Regulations govern the
development of plans and design the criteria implemented in the State. Current regulations
minimize water quality and quantity impacts due to land disturbing activities by preferring the
use of “Green Technology BMPs.” “Green Technology BMPs” are practices that achieve
stormwater management objectives by applying the principles of filtration, infiltration, and
storage associated with natural vegetation and undisturbed soils, while minimizing a reliance on
structural components. These BMPs are effective in nutrient reduction.
Additionally, the report “Governor Minner’s Task Force on Surface Water Management”
recommends including nutrient reduction as an aspect of sediment and stormwater law. As part
of recommendation 10, it is suggested that State Sediment and Stormwater Regulations and plans
be updated to include requirements for stormwater recharge, runoff volumes, land use cover
conditions, turbidity limits, adequate conveyance, and pollutant loads. The Sediment and
Stormwater Regulations are currently under revision and will be modified to better address
volume management by increasing emphasis on recharge and infiltration of stormwater, where it
is technically and environmentally feasible. In addition, regulations should include design
criteria to reduce nutrient contributions through practices such as comparing post development
conditions with and without stormwater quality controls, using treatment trains of stormwater
controls, or reducing impervious cover.
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Implementation Schedule: Promulgate regulations by end of 2012.
Expected Reduction:
Table 11: Effectiveness of various Stormwater BMPs to reduce nutrient (TN & TP)
Loads
Reduction Efficiency for
Stormwater BMP Reduction Efficiency for TN TP
1
Wet Ponds 0.30 0.50
Dry Ponds1 0.05 0.10
1
Sand Filters 0.40 0.60
1
Infiltration Systems 0.50 0.70
Biofiltration/bioswales1 0.50 0.70
1
Stormwater wetlands 0.3 0.50
1
Rain Gardens 0.40 0.60
1
: Chesapeake Bay Non- Point Source Best Management Practices Table 1, 2006.
Cost: Approximately $200,000 for consulting services for regulation development
Potential Funding Source: Funded through State general funds.
Action Needed: With the promulgation of the new proposed Sediment and Stormwater
Regulations by the end of 2012, the Department believes that this recommendation will be met.
If the new regulations are not promulgated as anticipated, the Department will promulgate
stormwater regulations for the St. Jones watershed that meet this recommendation and the
required TMDL reduction.
Nutrient Reducing Recommendation 11 – Impervious Cover
Local municipalities, Kent County Conservation District and Kent County, should meet to
determine how to limit the addition of new effective impervious cover and encourage the use
of pervious surfaces.
Implementation Goal: Implementation of new proposed Sediment and Stormwater Regulations
to limit effective impervious cover.
Basis for Recommendation: Limiting impervious cover reduces the amount of runoff that can
enter the river and its tributaries. Research has consistently shown that once a threshold of
imperviousness is crossed in a given watershed, water quality and stream habitat cannot be
maintained at the predevelopment level. The consensus among many independent researchers is
that watershed imperviousness should not exceed 10 percent in environmentally sensitive
watersheds. As research has uncovered the link between increasing impervious cover and
deteriorating water quality, businesses have developed pervious paving products that can replace
impervious products (Center for Watershed Protection, March 2003).
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The Department recommends that the effective impervious cover be reduced on redeveloped
properties. Effective impervious cover is the portion of the total amount impervious cover that is
directly connected to the storm drain system. Impervious cover that drains to vegetated areas
where stormwater can infiltrate, or be filtered and stored, is not considered part of the effective
impervious cover.
Kent County Code (Chapter 187, Article 5, §205-51) presently allows 20 percent of each lot to
be covered by impervious surfaces; however, this allotment does not include streets or other
impervious areas outside the lot boundary. Consequently, subdivisions have over 20 percent
impervious cover, while commercial lots could have 100 percent impervious cover. In 1992
impervious cover within the St. Jones watershed was estimated to be around 11 percent, and in
2007 is estimated to have increased to 12.5 percent. With the present rate of growth in the St.
Jones watershed in the past five years, impervious cover could be nearer 15%.
The State of Delaware Source Water Protection Law of 2001 requires local governments with
year-round populations of 2,000 or greater to implement measures to protect the quality and
quantity of public water supplied within delineated surface water, wellhead, and groundwater
recharge areas by 2007. This law required Dover, Camden, and Wyoming to develop measures
to protect source water.
In the Source Water Protection Guidance Manual for the Local Governments of Delaware, local
governments are encouraged to adopt ordinances that protect ground and surface waters in Water
Resources Protection Areas (WRPAs) through a source water protection hierarchy (ranked in
descending order of preference):
1. Preserve WRPAs as open space and parks by acquisition or conservation easement.
2. Limit impervious cover of new development to 20% within WRPAs.
3. Allow impervious cover of new development to exceed 20% within WRPAs (but no
more than 50% impervious) provided the applicant develops recharge facilities that
directly infiltrate rooftop runoff.
4. Allow impervious cover of new development to exceed 20% within WRPAs (but no
more than 50% impervious) provided the applicant develops recharge facilities that
infiltrate stormwater runoff from forested and/or grassed surfaces with pretreatment.
The new State Sediment and Stormwater Regulations are expected to limit some of the negative
effects of impervious cover by virtue of the requirement that stormwater must be infiltrated
rather than discharged through a conveyance system. If infiltration is not possible on the site, the
stormwater treatment on site must have several best management practices designed to reduce
the stormwater nutrient and bacteria load. As for existing properties that will be redeveloped,
unless new construction will be undertaken on the property, no reduction of impervious cover
will result.
Implementation Schedule: The new regulations will be promulgated by December of 2012.
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Expected Reduction: Although there have been links between percent impervious cover and
watershed health, nutrient loading rates for phosphorus and nitrogen have not been established
for percent imperviousness. Reducing runoff will reduce nutrient loads in the river, ponds, and
tributaries, although we do not have the ability to connect a numeric reduction with coverage
limits.
Cost: This recommendation would only apply for new proposed development so it is not
possible to calculate implementation costs at this time.
Potential Funding Source: In a study funded by DNREC (1997), the Brandywine Conservancy
demonstrated that by reducing road and driveway widths and minimizing the disturbance
boundary in developments in Kent County, the developer could reduce impervious cover 24%
and at the same time reduce development costs by 39%.
Action Needed: With the promulgation of the new proposed Sediment and Stormwater
Regulations by the end of 2012, the Department believes that this recommendation to establish
watershed-wide limit for effective impervious coverage will be met. The Department will work
with Kent County or any municipality to develop effective impervious cover reduction controls
through ordinances on redeveloped properties.
Nutrient Reducing Recommendation 12 – Stormwater Retrofits
A stormwater inventory should be conducted to identify areas where stormwater retrofits
would effectively reduce sediment and nutrients.
Implementation Goal: Use the existing stormwater BMP database to identify retrofit areas.
Basis for Recommendation: Land developed prior to 1990 did not have any stormwater
requirements. Kent County Conservation District has delegated authority from DNREC to run
the stormwater program in Kent County and is in the process of identifying priority areas for
stormwater retrofits.
DNREC hired Duffield Associates, Inc. to develop a Watershed Implementation Plan (2008) for the St.
Jones River. The purpose of the plan is to characterize the watershed quality, identify potential
sources/types/locations of impairment, and to identify potential restoration opportunities. The focus of
this watershed plan is to improve water quality and associated natural resources. A focus of the study
is to identify potential restoration opportunities in the watershed.
Restoration/enhancement/preservation opportunities were identified in the following major categories:
• Stream/Riparian Buffers/Floodplains;
• Wetlands;
• Agricultural Best Management Practices;
• Urban Stormwater Retrofits;
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• Urban Sub-Watershed Site Reconnaissance; and
• Conservation Easements or Acquisitions.
Implementation Schedule: Inventory was completed October 2008.
Expected Reduction: Nutrient reductions will depend on the specific systems selected for
upgrade and the acreages involved.
Cost: Cost of the St. Jones River Watershed Implementation Plan was $175,000. Cost will of
implementation depends on the specific systems selected for upgrades.
Potential Funding Source: State and federal grants
Action Needed: Implement the existing St. Jones River Watershed Implementation Plan.
Nutrient Reducing Recommendation 13 – Stormwater Education
Since Homeowners Associations are critical for successful stormwater BMP maintenance,
there should be a governmental agency charged with making sure the Associations are
functional. In the Association by-laws, there should be a requirement for stormwater
education. An education program for Homeowners Associations should be developed for
stormwater BMP maintenance.
Implementation Goal: Develop an education program for stormwater management and
maintenance.
Basis of Recommendation: Educational resources should be provided to homeowners
associations, especially face to face education, which stresses the organizations’ responsibilities.
Topics should include: proper use and application of fertilizer and use of salt and sand during
periods of snow. The Smartyard Program should be implemented in the watershed to assist
homeowners in planting native landscaping to conserve water and reduce fertilizer and pesticide
use.
The plan should consist of the following parts:
1. Identify values which are affecting residential activities and target those that will affect
behavior change.
2. Encourage educational facilities with turf athletic facilities where nutrients are applied to
develop a nutrient management plan for their facility.
3. Develop an advertising strategy that promotes the use of soil tests to the urban/suburban
homeowner.
4. Work with the University of Delaware to revise their soil test results sheet for
homeowners to make it easier to be understood and provide specific fertilizer application
recommendations based upon existing fertilizer blends found within the State.
5. Education of fertilizer retailers such that retailers will pass out educational materials with
purchase of fertilizer and will have available soil testing materials at their location.
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6. Educate homeowners and homeowner associations on stormwater BMPs that can be used
around the home to reduce impact on water quality.
7. Integrate education into various (State and local) permitting processes.
8. Create public information campaigns based upon goal of behavior change.
9. Support a demonstration project/workshop for homeowners on application of fertilizers
and composting methods.
10. Support and encourage the use of water conservation measures like those below by
individuals to help reduce the amount of nutrients leaving individual properties.
• Gray water recycling (use of gray water around the home on plants and gardens,
etc).
• Rain collection systems such as rain barrels and rain gardens.
• Directing stormwater runoff from roofs and impervious surfaces onto grassy
areas.
• The use of water saving devices in and around the home.
• The overall reduction of water usage in households and on lawns.
11. Work with the Delaware Nutrient Management Commission and the Master Gardeners to
provide education and programs for homeowner’s on lawn and garden best management
practices such as:
• Proper mowing practices.
• Leaving lawn clippings on the lawn.
• Leaving a buffer along stream edge.
• Reducing lawn size.
• Water conservation measures and stormwater BMPs for the lawn and garden.
• Encouraging use of native species and noninvasive species.
• Discouraging ideas that lawns need chemicals to be green.
• Proper use of lawn and garden chemicals (including natural fertilizers and
compost).
• Use of compost rather than chemicals as a means of reducing synthetic chemical
fertilizers.
Implementation Schedule: The Delaware Liveable Lawns program was initated in early 2010.
The Delaware Livable Lawns Program certifies lawn care companies that follow
environmentally-friendly practices in fertilizer application while educating homeowners. While
many homeowners may be unaware of where, when, and how much fertilizer to apply,
professional lawn care staff have the expertise to fertilize lawns correctly (See Nutrient Reducing
Recommendation 3). The Delaware Liveable Lawns website helps homeowners and commercial
applicators to learn about proper fertilization (www.delawarelivablelawns.org).
On September 15, 2010, “Rain Gardens for the Bays” – a regional campaign for greening our
neighborhoods and improving water quality in the Delaware Bay, Maryland Coastal Bays, and
Delaware’s Inland Bays was launched at the Delaware Agricultural Museum and Village in
Dover. At the event, Governor Jack Markell signed a Proclamation declaring Sept. 15 – 21,
2010 as “Rain Gardens for the Bays Week” in Delaware and encouraged the public to create rain
gardens where they work, live and play.
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A rain garden is a garden located in a shallow depression near a runoff source – a downspout,
driveway or paved surface – with soil that drains quickly and deep-rooted native plants and
grasses that naturally absorb water and filter pollutants. When rainwater from storms comes in
contact with buildings, roads, parking lots and other impervious surfaces, the runoff collects
pollutants – oil and grease, nutrients, bacteria, harmful metals, and other substances – and
deposits these pollutants in our waterways.
Rain gardens are sustainable, affordable and particularly effective in capturing rain water,
mitigating flooding, creating habitat for local species and reducing up to 80 percent of the
pollutants in stormwater runoff. The campaign includes a new one-stop website,
www.raingardensforthebays.org, with easy-to-use information and diagrams on how to design
and build a rain garden. Photos of rain gardens planted throughout the region are posted, and the
site encourages the registration of new rain gardens as a way to measure the progress of the
campaign. All new rain gardens registered on the website will receive a “Registered Rain
Garden” sign to post at their garden.
Funding for 10 demonstration rain gardens was awarded to the campaign through the federal
Clean Water Act Nonpoint Source Program via a grant to DNREC’s “319” program.
Demonstration rain gardens are being located throughout the region at public buildings, schools,
museums and other sites with public access, as a way to educate and encourage people to plant
rain gardens.
Expected Reduction: Nutrient reductions cannot be assigned to this recommendation as it is a
mechanism for education,though rain gardens can reduce nitrogen and phosphorus in stormwater
by as much 40% for nitrogen and 60% for phosphorus.
Cost: Unknown at this time and is a function of program developed. Liveable Lawns program
was begun with funds from DELDOT. The program cost $ 40,000 for the first year and will cost
$ 25,000 each year thereafter. The Rain Gardens for the Bays was initiated with $50,000 from
EPA and the program received and additional $50,000 in 2011 from EPA.
Potential Funding Source: State and/or Federal grants.
Action Needed: The Department will continue its education efforts for stormwater management
and will assist Kent County and municipalities with their education efforts.
Nutrient Reducing Recommendation 14 – Agricultural BMPs
Best Management Practices (BMPs) for agriculture should be encouraged and supported.
New funding sources should be sought and financial incentives should be increased.
Implementation Goal: Train Kent Conservation District staff to use existing targeting tool.
Basis for Recommendation: The establishment of best management practices on agricultural
land will address nutrient inputs from all facets of agriculture operations, including the use of
manure from animal operations and fertilizers for crops. The environmental and quality of life
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benefits of agriculture should be recognized as a way to encourage and enforce BMP
implementation. Encourage the use of buffers on agricultural lands where best nitrogen and
phosphorous uptake is likely. By targeting areas for BMP implementation geographically, more
effective and efficient nutrient reductions can likely be expected.
Specific BMPs that are used in the St. Jones watershed have many beneficial nutrient reducing
capabilities as follows:
• Cover crops protect soil when row crops are not being grown. This practice helps retain
nitrogen in the soil for the next crop, reducing fertilizer costs to the farmer.
• Grassed filter strips and grassed buffers trap sediments in surface runoff and take up
excess nutrients.
• Ponds capture nutrient losses from upland or cropped acreage.
• Riparian forested buffers reduce nutrient losses from upland acres and reduce sediment
bound phosphorous from entering waterways.
• Wetland restoration reduces nutrient loss from upland acres.
• Field border plantings trap sediment in surface runoff and take up excess nutrients.
• Manure relocation removes significant amounts of excess manure, consequently
removing excess nutrients.
The Kent Conservation District developed a Geographic Information System database of farm
fields to improve their ability to coordinate and effectively manage agricultural NPS pollutant
reductions. The spatial database will facilitate a more efficient:
• Consolidation of information from the numerous agricultural agencies that develop and
administer BMP and conservation practices.
• Approach to highlighting the geographic location of all existing BMP and conservation
practice locations in a designated watershed.
• Utilization of watershed planning tools capable of targeting and ranking farm field
properties for various BMP and conservation practice implementation.
This Geographic Information System database was developed to identify and target farm field
sites for potential enrollment in various state and federal agricultural voluntary cost-share
programs that address nutrient nonpoint source pollutant loading. This tool will allow the
District and its state and federal partner agencies to maximize the limited implementation funds
and planning resources earmarked for potential agricultural NPS loading sources within the St.
Jones.
Implementation Schedule: Have District staff trained by December 2012.
Expected Reduction: As of December 2010, agricultural best management practices on the
ground in the St. Jones River Watershed have reduced phosphorus loads by 58.30 lbs per day or
90 percent of the way towards the P load goal, and 88.61 lbs per day of nitrogen or 10 percent of
the way towards the nitrogen load goal.
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Cost: The costs of implementing BMPs have been estimated using data gathered by United
States Department of Agriculture (USDA), Natural Resource and Conservation Service (NRCS)
at the county and state level. Recently, changes in the state cost share program have required a
Pollution Control Strategy for watershed residents to receive funding. Thus, the state cost share
information found in Table 11 is based on a PCS approved for the St. Jones watershed. These
are estimates, as costs for specific project may vary.
Table 12: Agricultural BMP Costs
Installation Lifespan Total Total Cost/
Cost / Acre (years) Maintenance Acre
Costs over
Lifespan
Cover Crops $49.33 1 $5 $54.33
Ponds $3,758.50 10 $5 $3,808.50
Grassed
$16,404.24 10 $5 $16,454.24
Waterways
Filter
Strips/Wildlife $495.24 10 $5 $545.24
Habitat
Forest Buffers $495.24 15 $5 $570.24
Riparian
$502.00 15 $5 $577.00
Buffers
Wetland
$4,374.50 15 $5 $4,449.50
Restoration
Field Border $495.24 10 $5 $545.24
Critical Area
$7,229.24 10 $5 $7,279.24
Planting
Conservation
$17.33 4 $5 $37.33
Tillage
Potential Funding Sources: United States Department of Agriculture Natural Resource
Conservation Service, Farm Service Agency, Kent Conservation District, DNREC Watershed
Assessment, DNREC NPS Program 319 Funding, United States Fish and Wildlife Service,
DNREC Ecological Restoration Program, Delaware Department of Agriculture Nutrient
Management Commission
Nutrient Reducing Recommendation 15 – Nutrient Management Act
Because nutrient management plans reduce excess cropland nutrients, it is recommended that
the Nutrient Management Commission ensure full compliance of the Nutrient Management
Act.
Implementation Goal: This has been completed as of December 2007. However, the Delaware
Nutrient Management Commission is checking continuing to check compliance of Nutrient
Management Act.
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Basis for Recommendation: As of 2007, all lands (over 10 acres) that have nutrients applied
must be in compliance with the Nutrient Management Act. The Nutrient Management Act
requires all farms over 10 acres or with 8 animal units to establish a nutrient management plan,
which includes the use of fertilizers and the fate of manure. Assessing the impact of this
requirement will quantify the efficiency and reduction of nitrogen and phosphorus.
Since the baseline period (1997), the agricultural community has reduced a significant amount of
nonpoint source nutrient loading, leading the efforts to curtail nonpoint source nutrient loading.
From 1997 to 2008, multiple best management practices (BMPs) have been implemented, and
the Delaware Nutrient Management Act was passed. The 2002 Farm Bill has led to
unprecedented funding levels of cost-share programs for BMPs that protect the environment,
especially water quality, and with the 2008 Farm Bill, additional BMPs were constructed to
further improve water quality within the watershed. In many watersheds, polluted runoff from
cropland, manure-disposal sites, and concentrated animal-feeding operations (CAFOs) are some
of the important sources of phosphorus to surface waters. As of 2009, there were 18 poultry
operations, which produce approximately 696,004 birds annually, 18 Amish dairies, 13 beef
cattle operations, 31 equine and 5 goat operations in the St. Jones watershed [8]. There are 49
Amish farms within the watershed. Potential nutrient inputs are related to manure, runoff,
erosion, and atmospheric deposition of nutrients. In 2007, 37.4% of the St. Jones watershed was
used for agriculture, which equates to approximately 21,588 [9] acres. In 1997, agricultural land
use accounted for 44.7% [10] of the total land area in the watershed; therefore, the agricultural
activity is the second leading source. There are 21,588 acres of crops in the watershed. [11] Crops
require nutrients in order to produce an economic yield. Crops produced in the watershed may
include soybeans, potatoes, barley, wheat, corn, and vegetables. Nutrient inputs include fertilizer
and manure application, which when applied improperly can contribute to nutrient over-
enrichment in streams and tributaries in the St. Jones watershed.
The Delaware Conservation Partnership (DCP) conducted a survey in July 2007, after the
deadline requiring all eligible farm operations to have a plan, to evaluate nutrient management
planning in the state. The DCP consists of the Delaware Conservation Districts, the Natural
Resources Conservation Service, and the Delaware Department of Natural Resources and
Environmental Control, and strives to work together to meet the needs of Delaware farmers by
providing cost-share programs, educational opportunities, and nutrient management planning
services. The survey was designed to inform those programs by identifying gaps in information
and education and opportunities to spend cost-share dollars more effectively. In short, the
purpose of the project was to make nutrient management work better for farmers in Delaware.
The surveys were sent out to everyone who has been certified by the Nutrient Management
Program- 2,034 people in all. The Delaware Conservation Partnership received 698 responses-
about a 34% response rate. The following shows the breakdown of responses among different
sizes of farms:
[8]
Mark Hogan, Nonpoint Source 319 Program, DNREC. 02010. Personal Communication.
[9]
2007 Landuse data
[10]
1997 Landuse data
[11]
Glenn Gladders, Nonpoint Source 319 Program, DNREC. 2004. Personal Communication.
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1-10 Acres- 9% 100-499 Acres- 25%
11-99 Acres- 29% 500+ Acres- 20%
Animals Only- 10%
The survey indicated that fertilizer application rates have most severely decreased among
farmers who till at least 500 acres, while manure applications have most dramatically decreased
among farmers who till between 11 and 99 acres. The County determined that Sussex farmers
had the highest reduction rate of N and P fertilizer applications, Kent farmers had the lowest rate
of N applications, and New Castle farmers had the lowest rate of P applications.
An Agricultural Workgroup was established to gather the best available science on nonpoint
source pollution prevention and compare efficiencies based on the DCP survey to other estimates
of nutrient management planning effectiveness. The Workgroup operated off the basic
assumption that if fewer nutrients are being applied to the land, fewer nutrients will be lost to
Delaware’s water bodies. From this premise, the Workgroup determined nutrient efficiencies for
various agricultural best management practices including the effectiveness of nutrient
management planning as seen in Table 12.
Table 13. Percent changes in fertilizer and manure application rates by county as a
result of the 2002 Nutrient Management Law (data from 2007 DCP Survey)
County Acres in farms Change in Change in Change
nitrogen phosphorus in
fertilizer fertilizer manure
applications applications applicati
on
Kent 173,808 13.4 26.9 5.4
New Castle 16.0 20.1 13.6
66,981
Sussex 269,464 18.5 37.1 24.2
Statewide weighted average 510,253 16.7 31.0 19.9
Initially, the Workgroup looked at the impact of nutrient management planning (NMP) in the
Inland Bays and Nanticoke watersheds from a study by McGowan and Milliken (1992). This
study listed the reductions associated with various management practices observed over a three
year period, with a total of 103,736 lbs TN reduced by 2,328 acres under nutrient management
planning. To determine a general NMP TN reduction, the Workgroup removed the reductions
and acreage associated with manure allowance and cover crops from further calculations; the
reductions for both of these items are determined separately and all NMPs will not include
manure relocation. This subtraction gave a total of 1,224 acres of nutrient management
planning, and a load reduction of 70,136 lbs of TN, resulting in a reduction rate of 57.3 lbs/acre
per 3-year planning cycle. McGowan and Milliken (1992) reported that the TN application rate
prior to the introduction of NMPs was 280 lbs/acre per 3-year planning cycle, so NMPs produced
a 20.5% reduction in TN. This estimate falls in the lower range reported by the State of
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Maryland (MDNR, 1996), which was 20-39% for nitrogen. The corresponding phosphorus
range reported by the Maryland DNR was 9-30%.
In the Appoquinimink watershed, one representative farm within the watershed volunteered to
allow the Workgroup to analyze the nutrient data they routinely gather. This particular farm
tracks nutrient application rates to each crop field within a database that goes back to 1999, prior
to the passing of the Nutrient Management Act. The data was separated into two groups, pre-
Nutrient Management Plans (NMPs) (1999-2002) and post-NMPs (2003-2004), and entered into
Statgraphics Software for statistical analysis. It was determined that there was a statistically
significant difference between the mean application rates at the 95% confidence level for
nitrogen. The average nitrogen application rate decreased by 12.4% from the pre-NMP level and
this value will be taken as the NMP reduction efficiency; unfortunately, no reduction could be
calculated for phosphorus from this data.
At the request of the NMC, Sims et al. (2008) conducted extensive nutrient mass balance
calculations for the State for the years 1996 through 2006. They calculated both input/output and
management–oriented mass balances for nitrogen and phosphorus. The Sims et al. (2008)
approach included calculations for manure relocation and estimates of biological fixation of
nitrogen by leguminous crop and clearly demonstrated that fewer nutrients are being applied to
Delaware’s cropland.
The Watershed Assessment Section (WAS) has worked with the NMC and the University of
Delaware Cooperative Extension to determine the impact of the Nutrient Management Act on the
amount of nutrients applied to Delaware’s agricultural fields. Using an input-output type
analysis using fertilizer sales data and crop yields, WAS determined that on a state-wide basis,
47% less nitrogen and 62% less phosphorus has been applied to Delaware’s cropland. Both the
WAS and Sims et al. (2008) approach produced similar results.
The DCP values, which are based on the reductions in nutrient applications actually reported by
Delaware farmers, fall within the range of efficiencies determined by the numerous other
methods and data sets discussed above. As a result, DNREC proposed to use the DCP
efficiencies to estimate the reduction in nutrient application rates resulting from the promulgation
of the Nutrient Management Law.
Implementation Schedule: Check for compliance of Nutrient Management Act December of
each year.
Expected Reduction: Total Phosphorus 51.10 lbs/day and 61.18 lbs/day of Total Nitrogen
Cost: Estimated up to $93,900. Because nutrient management plans reduce excess cropland
nutrients, it is strongly recommended that the Nutrient Management Commission ensure full
compliance of the Nutrient Management Act. The cost to develop a nutrient management plan
decreases as the acreage in the plan increases. A three year plan for an operation with less than
500 acres costs $5.70, with 501-1,000 acres cost $4.50, with 1,001-2,000 acres cost $3.90, and
with more than 2,000 acres cost $3.30 (DNMC, 2004). The average of these values is $4.35/acre
every three years, which when annualized is $1.45/acre/year. Farmers can be reimbursed the
entire cost for developing a nutrient management plan from the Delaware Nutrient Management
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Commission. The cost can also be expressed as $0.34/lb TN reduction. At this time, phosphorus
reductions are not being calculated for NMPs.
Potential Funding Sources: Delaware Nutrient Management Commission, State of Delaware
Cost Share, DNREC Watershed Assessment, and/or NPS Program 319 Funding
Action Needed: The Department and Delaware Department of Agriculture should assess the
impact of nutrient management planning as required by the Nutrient Management Law. Both
Departments as well as the Delaware Nutrient Management Commission are actively quantifying
the effect of nutrient management on water quality.
Nutrient Reducing Recommendation 16 – Stream Monitoring
Ongoing in-stream monitoring must be done in order to quantify the amount of nutrients in
the waterways of the St. Jones watershed.
Implementation Goal: On a routine basis, monitor surface water quality of St. Jones River
through DNREC’s GAMN stations.
Basis for Recommendation: Monitoring plans help determine the effectiveness of watershed
projects that aim to improve TMDLs and overall water quality. As a result, it is important to
institute tracking and monitoring systems to measure improvements in subwatershed indicators
over time. These systems include the internal tracking of restoration projects in each sub-
watershed, as well as monitoring of stream indicators at sentinel monitoring stations.
Performance monitoring of individual restoration projects can be tracked to improve the design
of future restoration practices. Information gathered from a tracking system is then used to
revise or improve the restoration plan over a multi-year cycle.
Undoubtedly, over time, the St. Jones watershed will experience significant changes in land use.
Monitoring plans for water quality improvement should take in to account the possibility of build
out and the associated impacts. As a result, the following monitoring approaches are
recommended:
Project Monitoring (Milestone Monitoring): As warranted, small scale (reach or smaller)
project monitoring should be conducted to illustrate benefits of individual restoration efforts.
Project managers will want to invest in both in-stream and non-stream monitoring of individual
restoration projects to assist in measuring project success. Such monitoring can be relatively
simple (observing the success of a reforestation project or measuring public awareness through
surveys) or extremely complex and expensive (measuring the pollutant reduction of a storm
water retrofit or the biological response to a comprehensive stream restoration project). On an
annual basis, information derived from the baseline and project monitoring should be compiled
into a report.
The annual report should summarize current biological and physical conditions in the watershed;
the number, type, and extent of projects taken; and the St. Jones success to date of the plan in
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improving watershed conditions. Reporting on an annual basis will allow for mid-course
corrections and adjustments to be made based on the monitoring data.
Sentinel Station Monitoring: Sentinel monitoring stations are fixed, long-term monitoring
stations which are established to measure trends in key indicators over many years. DNRECs
Water Quality Monitoring stations (GAMN) contain the history of data necessary to detect trends
in water quality that would be beneficial to determine project success in removing targeted
pollutants. These are the stations which TMDL data was calibrated.
If future funding allows, it is recommended to expand the GAMN station locations to include
routine sampling of those station currently only monitored on an as needed basis. This would
allow for data continuity and ease of collection. In addition, if additional point sources are
discovered or added, downstream sampling sites should be added. Additionally, as warranted on
a project specific basis, increase sampling will occur to measure and document BMP efficiency.
Illicit Discharge Monitoring: Illicit discharge detection and investigation are critical elements
of watershed restoration and planning especially when there are obvious indicators of illicit
discharges. Illicit discharges are often a significant source of pollution in a watershed that occurs
repeatedly in association with specific polluting behaviors. The NPDES stations are areas where
illicit discharges can be detected. Additionally, volunteer stream assessments which could be
conducted yearly could identify potential illicit discharges.
Implementation Schedule: DNREC evaluates its monitoring plan yearly to maximize
monitoring dollars with sampling needs.
Expected Reduction: An efficiency and reduction value cannot be assigned to this
recommendation. Monitoring does not have a direct reduction.
Cost: Each year the State spends $71,000,000 on sampling and monitoring.
Potential Funding Sources: DNREC receives state funding and EPA funds for its surface water
monitoring program.
Action Needed: The Department has calculated nitrogen and phosphorus loads from existing
water quality and flow data to determine if TMDL reductions are being met on a yearly basis.
These calculations have been completed for the years 2002 through 2010. From 2002 data,
TMDL have not been met. For phosphorus in the St Jones River, during years of lower stream
flow, the phosphorus TMDL was met but during wet years with higher flows the phosphorus
TMDL was not met.
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Total Nitrogen Load (lb/year)
900,000 180.0
800,000 160.0
700,000 140.0
600,000 120.0
Flow (cfs)
500,000 100.0
lb/year
400,000 80.0
300,000 60.0
200,000 40.0
100,000 20.0
0 0.0
TMDL*
2002/200 2006 2007 2008 2009 2010
3…
Figure 7 - Total Nitrogen loads in the St Jones watershed from 2003 to 2010
Figure 8 - Total Phosphorus loads in the St Jones watershed from 2003 to 2010
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ANALYSIS FOR TMDL ACHIEVEMENT AND COST
Promulgation of this Pollution Control Strategy and full implementation of its elements should
lead to the achievement of the TMDLs for Total Nitrogen (TN) and Total Phosphorus (TP).
Because of the lag time between seeing improvements in ground and surface water quality,
estimated to be up to 30 years, improved water quality conditions will not be realized
immediately. The Department will continue to monitor water quality as will many citizen
volunteers. The Department is committed to revisit this Pollution Control Strategy in 10 years to
ensure that water quality is improving with implementation of the regulations and voluntary
practices called for within this document.
Analysis using a basic land use loading rate model shows that, to date, nonpoint sources of TP
and TN have been reduced by 151% and 34%, respectively. Voluntary programs for installation
of agricultural best management practices have been extremely successful as well as the
County’s and local governments’ efforts to protect open space and riparian buffers.
Implementation of the Delaware Sediment and Stormwater Law has also led to decreases in
nutrient loading.
The Total Phosphorus reduction is easily achieved in the St Jones Watershed, but the required
Total Nitrogen reduction is much more difficult to achieve. The existing best management
practices only reduced the total nitrogen load to the St Jones by 123 pounds and an additional
245 pounds of total nitrogen is still needed in order to meet required TMDL of 368 pounds per
day reduction. Those additional 245 pounds will come from converting dry pond into
bioretention facility, by completing existing and proposed projects along the St Jones near Silver
Lake Park (Silver lake Commission, 2011), by increasing cover crop acreage and by wetland
restoration and riparian buffer creation on both public and private lands. Connecting septic
systems to the Kent County wastewater treatment facility will also reduce the nitrogen load to
the St. Jones. Table 13 lists the acreage needed from the various best management practices in
order to achieve the required TMDL reduction.
While current implemented practices have been shown to help reach the required reductions, it is
important to note that there are practices that are still necessary to keep the watershed healthy
and meeting its TMDL required reductions. The most important area for future implementation
is wastewater. This includes requiring existing septic tanks to be pumped out at time of property
transfer and preferably once every three years, continuing to connect existing septic tanks to
sewer systems and implementing technologies that will allow systems to meet performance
standards to remove nutrients. In addition, realizing that development is still occurring
throughout the watershed and stormwater best management practices are required, future BMP
implementation must move away from practices that only deal with water quantity, but also
provide significant water quality benefits. Also, the strategy is based on the maintenance of
agricultural practices currently in place as well as the continued push towards open space and
riparian buffer preservation. Thus, future practices are critical towards meeting the TMDL
required reductions as you can see in Figures 6 and 7 which show that future practices put TP to
be reduced by 223% and TN by 100% towards the goal, as depicted by the green target lines.
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Table 14: Best Management Practices Goals for Achieving the St Jones Watershed
TMDL Reductions
Total
Total Nitrogen
Phosphorus
Best Management Practice Acres Reduced
reduced
(lbs/day)
(lbs/day)
Urban
Dry Pond conversion to Bioretention practice 1272 9.73 1.53
0.18
Silver Mills Regenerative step pool 200 0.68
Silver Lake Mill Race 20 0.17 0.03
Wetland enhancement
Central Middle School Regenerative steep 0.03 0.05
50
Pool
1200 feet
St Jones stream bank restoration at Central
of shore 0.66 0.1
Middle School
line
Total proposed reduction 11.27 1.89
Agriculture
Cover Crops 12,063 174.27 6.12
Riparian buffer on public and private lands 1589.71 42.66 4.77
352 11.51 6.20
Wetland Restoration
Total proposed reduction 228.44 17.09
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120 Total Phosphorus TMDL Reduction
Total Phosphorus reduction
100
80 Septic future
Agriculture to date
(lbs per day)
60 Stormwater to date
Target Reduction
Septic to date
40 Ag to urban conversion
Agriculture future
20 Stormwater future
Septic future
0
Figure 9 - Total Phosphorus Reduced in the St. Jones Watershed
400
Total Nitrogen TMDL Progress
Total Nirogen Reduction (Ibs per
350
Target reduction
300
250
200
day)
150
Septic future
100
Ag to urban conversion
Agriculture future
50
Stormwater future
0 Agriculture to date
Stormwater to date
Septic to date
Figure 10 - Total Nitrogen Reduced in the St. Jones Watershed
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Overall, this strategy costs over $103,000,000 including capital expenditures plus annual
operation and maintenance costs of various best management practices. Of this strategy total,
about $23,000,000 (about 23%) has already been paid for the installation of current practices.
Figure 11 shows the total strategy costs for each category of BMP including current and future
practices.
$80,000,000
$70,000,000
$60,000,000
Cost of Full Strategy Implementation
Future Costs (Maintenance
and Future Installation)
$50,000,000
$40,000,000
$30,000,000 Costs Already Paid for
Installation
$20,000,000
$10,000,000
$0
ltu re
St or m
Ag w at er
W
ric as te
u w at er
Figure 11 - Total Strategy Implementation Costs
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Every effort has been made to make the Strategy fair and equitable. It impacts everyone in the
watershed given that all activities contribute to nutrient loading. And, it attempts to take cost
into consideration through promoting the least expensive actions and cost-share for those actions
that are more expensive. The Department intends to review the Strategy in 10 years and update
it if further actions are needed to improve water quality.
IMPLEMENTATION PROGRAMS
Pollution of the St. Jones has been an ongoing occurrence over a long span of time by many
people. Implementing its Pollution Control Strategy will necessitate participation from a broad
variety of programs, agencies, nonprofit, and community organizations. These programs will
provide technical, financial, and administrative assistance in the effort to clean up these waters.
Coastal Nonpoint Program – 6217
The Coastal Nonpoint Program was established by Congress in 1990 under section 6217 of the
Coastal Zone Act Reauthorization Amendments (CZARA) to ensure that coastal states have the
tools needed to address polluted runoff. A consistent set of management measures was
established for states to use in controlling polluted runoff. Management measures are designed
to prevent polluted runoff resulting from a variety of sources. The program includes enforceable
policies and mechanisms to ensure implementation of the measures. The Delaware Coastal
Nonpoint Program is administered in the State of Delaware by the Delaware Coastal Programs in
the Department of Natural Resources and Environmental Control. Delaware’s Coastal Nonpoint
Program is a networked program with implementation responsibilities distributed throughout the
State. The Delaware Coastal Programs receives an annual award used to aid in the
implementation of management measures, program initiatives and the funding of grants for
projects designed to preserve and protect Delaware’s waterways from the degradation of
nonpoint source pollution. Through cooperative efforts will both government agencies and local
organizations, numerous projects have been designed and funded to help address issues
concerning nonpoint source pollution in Delaware.
The Delaware Forest Service
The Delaware Forest Service is a section of the Delaware Department of Agriculture and is
charged to improve and enhance the state rural and urban forest resources. Delaware’s Forest
Service staff, through the Urban and Community Forestry Program, provides technical,
educational and financial assistance to cities, towns, communities, developers and local
governments to develop a community forestry management plans and resource evaluation
studies. Foresters also review new planned subdivisions in order to conserve forest resources.
Additionally, the program provides annual grant assistance to a variety of partners to provide
both tree planting and tree care activities. Also, the professional foresters help private and public
landowners to improve their forest resources through a variety of services. This technical
assistance encompasses a wide range of forest management activities including reforestation,
timber stand improvements, timber harvesting and forest management plan development.
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DNREC -- Groundwater Discharges Section
Located within the Division of Water, the Groundwater Discharges Section is responsible for
overseeing all aspects of the siting, design and installation of on-site wastewater treatment and
disposal systems. This is a three step process which includes the site evaluation, the
design/permit application and the construction/installation of the system. The Small Systems
Permitting Branch reviews and approves site evaluations, permit applications and conducts
inspections of system installations. Experimental/alternative technologies and advanced
treatment units are approved and permitted for use by the Large Systems Permitting Branch. The
Section is also responsible for the permitting of underground injection wells, large spray
irrigation wastewater systems, and other means associated with land application wastewater
treatment. The Section also issues waste transporter permits and licenses to designers,
percolation testers, site evaluators and system installers.
DNREC – Nonpoint Source Program
The Delaware Nonpoint Source Program (NPS) administers a competitive grant made possible
through Section 319 of the Clean Water Act. It is housed under the Division of Watershed
Stewardship within the Department of Natural Resources and Environmental Control. The grant
provides funding for projects designed to reduce nonpoint source pollution in Delaware. NPS
pollution may be defined as any pollution that originates from a diffuse source (such as an open
field or road) and is transported to surface or ground waters through leaching or runoff.
Reduction of NPS pollution, but most frequently involve agriculture, silvilculture, construction,
marinas and septic systems. Proposals are reviewed and evaluated, and those which are
determined to meet specific requirements are eligible for funding. All projects must include
matching funding from a non-Federal source totaling at least 40 percent of the overall project
cost. In addition to funding projects that achieve reductions in NPS pollution, the Delaware NPS
Program is committed to addressing the issue through educational programs, publications and
partnerships with other organizations working to reduce NPS pollution in Delaware.
DNREC-Sediment and Stormwater Program
The Sediment and Stormwater Program is managed by the Division of Watershed Stewardship in
the Department of Natural Resources and Environmental Control. Delaware’s stormwater
management program requires sediment control during construction and post-construction,
stormwater quantity and water quality control. This program functions from the time
construction begins through a project’s lifespan. It requires construction and development
projects to obtain sediment control and stormwater plan approval, be inspected during
construction, and a post-construction inspection of permanent stormwater facilities and education
and training. The program’s initial emphasis is to prevent existing flooding or water quality
from worsening and limit further degradation until more comprehensive, watershed approaches
(as detailed in State legislation and regulations) are adopted. Current regulations require
stormwater management practices to achieve an 80 percent reduction in total suspended solids
load after a site has been developed. This is achievable with present technology. Long-term
removal rates over 80 percent may require other measures, such as water re-use, which may be
required locally. In Delaware, day-to-day inspection responsibilities are handled by the
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delegated local agency, but projects where site compliance is not possible are handled by the
State with progressive and aggressive enforcement, including civil and criminal penalty
provisions.
DNREC - Surface Water Discharges Program
The Surface Water Discharges Program is delegated to the Division of Water in the Department
of Natural Resources and Environmental Control. Program administrators are responsible for
eliminating pollutant discharges into State surface waters by issuing regulatory permits under the
National Pollutant Discharge Elimination System (NPDES). An NPDES permit legally
sanctions the discharge of substances that may become pollutants. However, the NPDES permit
is designed to limit the discharge of those substances so that there will be no adverse effect on
the quality of the receiving waters or interference with the designated uses of those waters. The
health of a water body is measured by its attainment of designated uses. If potential pollutants in
a NPDES discharge are reduced to levels that allow receiving waters to meet applicable
designated uses, then, in effect, the pollutant discharge has been eliminated.
Municipal sewage treatment or industrial plants that discharge wastewater to surface waters of
Delaware are issued permits specifying discharge limitations, monitoring requirements and other
terms and conditions that must be met to be allowed to discharge. In addition to wastewater,
wastewater facilities often generate a waste sludge solid that is also an NPDES discharge under
federal and State regulations. The NPDES General Permit for “stormwater discharges associated
with industrial activities,” a single permitting regulation with requirements that apply to a group
of similar dischargers is also issued to industrial sites that discharge only stormwater.
DNREC – Water Supply Section – Groundwater Protection Branch
This program is responsible for providing technical review of permit applications for non-
hazardous waste sites (i.e. large septic, wastewater spray irrigation, sludge application) and for
water well permit applications where wells are located near problem sites. Staff hydrologists
conduct investigations based on public complaints of groundwater quality, often associated with
domestic water wells.
The Source Water Protection Program (SWPP) has been delegated to DNREC and is managed
by the Water Supply Section, Groundwater Protection Branch of the Division of Water. This
program was created from the 1996 Amendments from the Safe Drinking Water Act. The SWPP
is responsible for determining the locations of water supplies used for public drinking water.
The program is also responsible for mapping the wellhead protection areas (those areas around a
well or group of wells from which a source obtains within those delineated areas, and
determining the susceptibility of the drinking water source to contamination. The SWPP is
required to make this information available to the public and does so through the program’s
website: www.wr.udel.edu/swaphome/index.html. Through the Source Water Protection Law of
2001, the SWPP was charged with the development of a guidance manual for the protection of
source water areas. This manual was development to give the counties and those municipalities
containing 2000 or more persons) ideas on methods that could be used to protect those areas by
2007.
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Local Governments
County and local governments have the authority to enact ordinances to further the goals of this
Pollution Control Strategy. They are all required to complete Comprehensive Plans and address
how they intend on assisting in the implementation of the TMDLs. Many of these entities have
ordinances that require buffers, open space and maximum impervious coverage – ordinances that
work towards achieving water quality standards. Local governments within the TMDL
watershed include: Kent County, City of Dover, Town of Cheswold, Town of Camden, Town of
Wyoming, Town of Woodside, Town of Magnolia, and Town of Bowers Beach.
Nutrient Management Commission
The Delaware Nutrient Management Program was established as a result of the Delaware
Nutrient Management Law. The Delaware Nutrient Management Commission (DNMC) was
established to direct the program and develop regulations pertaining to nutrient management,
waste management for Animal Feeding Operations (AFOs) and National Pollutant Discharge
Elimination System (NPDES) permits for concentrated animal feeding operations (CAFOs). The
DNMC manages activities involving the generation and application of nutrients in order to help
maintain and improve the quality of Delaware’s ground and surface waters to help meet or
exceed federally mandated water quality standards in the interest of the overall public welfare.
All persons who operate an animal feeding operation in excess of 8 animal units (1 AU = 1,000
pounds) and/or control/manage property in excess of 10 acres where nutrients are applied must
develop and implement a nutrient management or animal waste plan. The DNMC provides cost
assistance programs, certifications and investigation of complaints.
Office of State Planning Coordination
The mission of the Office of State Planning Coordination (OSPC) is “the continuous
improvement of the coordination and effectiveness of land use decisions made by state, county
and municipal governments while building and maintaining a high quality of life in the State of
Delaware.” Under the new PLUS (preliminary land use service) process, the OSPC will bring
together State agencies and developers early in the development process in order to try to
identify and mitigate potential impacts. The OSPC also supports the Governor’s “Livable
Delaware” initiative and has published Better Models for Development in Delaware that includes
many best management practices which will be needed in order to achieve the TMDL.
Soil and Water Conservation Districts
County Conservation Districts were created by State law and are administer through Delaware
Natural Resources and Environmental Control. They operate the State Conservation Cost Share
Program which provides funds for installation of agricultural management practices, promote the
State Revolving Loan Fund Program for poultry producers (low-interest loans to implement best
management practices) and are the delegated agencies for the Sediment and Stormwater
Management Program carrying out plan review and field inspections in their respective counties.
Watersheds prioritized by Delaware’s Nonpoint Source (Section 319) Pollution Program can be
targeted by these activities.
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Ames, D. and R. Dean, 1999. Projected Population Growth and the New Arithmetic of
Development in Delaware: 1990 to 2020, a report prepared for the Office of State Planning
Coordination, State of Delaware.
ASCE, 2001. Guide for best Management Practice (BMP) Selection in Urban Developed Areas.
American Society of Civil Engineers, Reston, Virginia.
Boesch, D.F., R.B. Brinsfield, and R.E. Magnien. 2001. Chesapeake Bay
Eutrophication: Scientific Understanding, Ecosystem Restoration and Challenges
for Agriculture. Journal of Environmental Quality, 30: 303-320.
Cech, T.V., 2002. Principles of Water Resources: History, Development, Management, and
Policy. John Wiley & Sons, Inc.
Center for Watershed Protection. March 2003. Impacts of Impervious Cover on
Aquatic Systems. Watershed Protection Research Monograph No. 1. Ellicott City,
Maryland.
Chesapeake Bay Program, 1998. Chesapeake Bay Watershed Model Application and
Calculation of Nutrient and Sediment Loadings, Appendix H: Tracking Best Management
Practice Nutrient Reductions in the Chesapeake Bay Program. A report of the Chesapeake Bay
Program Modeling Subcommittee, Annapolis, Maryland
Chesapeake Bay Program, 2010. Estimates of County-Level nitrogen and phorphorus data for
use in modeling pollutant reduction. Documentation for Scenario builder version 2.2.
DNMC, 2005. 2004 Annual Report of the Delaware Nutrient Management Commission to
Governor Ruth Ann Minner and the 143rd Delaware General Assembly. Delaware Nutrient
Management Commission, Dover, DE.
DNREC, 1994. Red Mill Pond, Final Report. Delaware Department of Natural Resources and
Environmental Control, Dover, Delaware.
DNREC, 1995. A Comprehensive Conservation and Management Plan for Delaware’s Inland
Bays. Delaware Department of Natural Resources and Environmental Control, Dover, DE.
DNREC, 1996. State of Delaware 1996 Watershed Assessment Report (305(b)).
Delaware Department of Natural Resources and Environmental Control, Dover,
DE.
DNREC, 2000a. State of Delaware 2000 Watershed Assessment Report (305(b)).
Delaware Department of Natural Resources and Environmental Control, Dover,
DE.
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DNREC, 2000b. Whole Basin Management: Inland Bays Environmental Profile-An
Environmental Assessment of Southeastern Delaware. Delaware Department of
Natural Resources and Environmental Control, Dover, DE.
DNREC, 2001. Total Maximum Daily Load for the St Jones Watershed. Amended for Bacteria
in 2005. Delaware Department of Natural Resources and Environmental Control, Dover, DE.
DNREC,2002. Regulations Governing the Design, Installation and Operation of On-Site
Wastewater Treatment and Disposal Systems. Delaware Department of Natural Resources and
Environmental Control, Dover, DE.
DNREC, 2002. State of Delaware 2002 Watershed Assessment Report (305(b)).
Delaware Department of Natural Resources and Environmental Control, Dover,
DE.
DNREC, 2004. State of Delaware Surface Water Quality Standards, as Amended July, 1, 2004.
Department of Natural Resources and Environmental Control, Dover, DE.
DNREC, 2005. Governor Minner’s Task Force on Surface Water Management- A report in
response to Executive Order No.62. Department of Natural Resources and Environmental
Control, Dover,
DDOSPC, 1999. Gross Land Use Changes in Delaware: 1992 to 1997. Delaware Office
of State Planning Coordination, Dover, DE.
DOSPC, 2002. 2002 Land Use and Land Cover Data. Delaware Office of State Planning
Coordination, Dover, DE.
DOSPC, 2007. 2007 Land Use and Land Cover Data. Delaware Office of State Planning
Coordination, Dover, DE.
EPA, 2002. Mid-Atlantic Integrated Assessment 1997-98 Summary Report, EPA/620/R-
02/003. U.S. Environmental Protection Agency, Atlantic Ecology Division,
Narragansett, RI.
EPA, 2003. Nutrient and Dissolved Oxygen TMDL Development for St Jones River, Delaware.
U. S. Environmental Protection Agency, Philadelphia, PA.
EPA. 2007. Reducing Stormwater Costs through Low Impact Development (LID) Strategies and
Practices, EPA publication number 841-F-07-006, December 2007.
Evans, R.O., J.W. Gilliam, R.W. Skaggs. 1989. Effects of Agricultural Water Table
Management on Drainage Water Quality. The Water Resources Research Institute, Report No.
237.
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Evans, R.O., J.W. Gilliam, R.W. Skaggs. 1996. Controlled Drainage Management Guidelines
for Improving Drainage Water Quality. North Carolina Cooperative Extension Service,
Publication Number: AG 443.
Fetter, C.W., 1994. Applied Hydrogeology: Third Edition. Prentice Hall, Inc.,
Englwood Cliffs, NJ.
Gold, A.J. and J.T. Sims, 2000. Research Needs in Decentralized Wastewater Treatment and
management: A Risk-Based Approach to Nutrient Contamination.. In: National Research Needs
Conference Proceedings: Risk-Based Decision Making for Onsite Wastewater Treatment,
Published by Electric Power Research Institute, Palo Alto, CA, US Environmental Protection
Agency and National Decentralized Water Resources Capacity Development Project: Final
Report March 2001.
Herlihy, A.T., J.L. Stoddard, and C.B. Johnson, 1998. The Relationship Between Stream
Chemistry and Watershed Land Cover Data in the Mid-Atlantic Region, U.S.
Water, Air, and Soil Pollution, 105: 377-386.
Horsley and Witten, Inc., 1998. Assessment of Nitrogen Loading to the Delaware Inland
Bays, a report prepared for the Center for the Inland Bays, Lewes, DE.
Jennings, J.A., J.R. Scudlark, K.B. Savidge, and W.J. Ullman, 2003. Estuarine
Eutrophication by Atmospheric Phosphorus. Poster Presentation to the National
Atmospheric Deposition Program Annual Conference, Washington D.C., October
20-22, 2003.
Johnston, R.H., 1976. Relation of Ground Water to Surface Water in Four Small Basins
of the Delaware Coastal Plain. Delaware Geological Survey Report of
Investigations, No. 24.
Jones, Lyle and Volk Jennifer. 2008. Effect of Delaware’s Nutrient Management Law On
Nutrients Sold in Delaware and Its Apparent Impact on Nitrogen and Phosphorus Total
Maximum Daily Loads ---- Another Perspective Unpublished
Jordan, T.E., D.L. Correll, and D.E. Weller. 1997. Effects of Agriculture on Discharges
of Nutrients from Coastal Plain Watersheds of Chesapeake Bay. Journal of
Environmental Quality, 26: 836-848.
McGowan, W.A. and W.J. Milliken. 1992. Nitrogen Usage and Nutrient Management in the
Inland Bays Hydrologic Unit. Cooperative Extension, Research and Education Center, College
of Agricultural Sciences, University of Delaware, Georgetown, Delaware.
Sims, J.T., J. McGrath, and A.L. Shober. 2007. Nutrient Mass Balances for the State of
Delaware: Final Project Report, Submitted to the Delaware Nutrient Management Commission.
University of Delaware, Newark, DE.
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MDNR, 1996. Technical Appendix for Maryland’s Tributary Strategies: Documentation of
Data Sources and Methodology Used in Developing Nutrient Reduction and Cost Estimates for
Maryland’s Tributary Strategies. Maryland Department of Natural Resources, Maryland
Department of the Environment, Maryland Department of Agriculture, Maryland Office of
Planning, University of Maryland, Office of the Governor.
Metcalf and Eddy, 1991. Wastewater Engineering: Treatment, Disposal, and Reuse (3rd
Edition). McGraw-Hill, New York, New York.
NADP, 2003. National Atmospheric Deposition Program-Atmospheric Integrated
Research Monitoring Network website: http://nadp.sws.uiuc.edu/AIRMoN/.
Nelson, J., 2008. Results from the Delaware Nutrient Management Survey. Delaware
Conservation Partnership published in conjunction with DNREC 319 Nonpoint Source Program.
Dover, DE.
Ritter, W.F., 1986. Nutrient Budgets for the Inland Bays, a report prepared for the
Delaware Department of Natural Resources and Environmental Control.
Ritter, W. F. and M. A. Levan, 1993. Nutrient Budgets for the St Jones
Watershed. Delaware Department of Natural Resources and Environmental Control.
Sims et al., 1994. Development of Management Practices to Reduce Soluble
Phosphorus Losses from Agricultural Soils In the St Jones Watershed.
Silver Lake Commission, 2011. Silver Lake Sub-Watershed Implementation Strategy for the
Silver Lake Commission, City of Dover, DE.
Sims, J.T., J. McGrath, and A.L. Shober. 2007. Nutrient Mass Balances for the State of
Delaware: Final Project Report, Submitted to the Delaware Nutrient Management Commission.
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URS Corporation. 2010. Kent County Surface Water Management Level of Surface Analysis.
Perpared for DNREC, Division of Soil and Water Conservation, Kent Conservation District and
Kent County, Dover, DE.
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2000 Travel Trends. The Research Department of the Travel Industry
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Environmental Pollution, 135(3): 399-406.
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Appendix A - 7426 TMDLs for the St. Jones River Watershed, Delaware
1.0 Introduction and Background
Water quality monitoring performed by the Department of Natural Resources and Environmental
Control (DNREC) has shown that the waters of St. Jones River and several of its tributaries and
ponds are impaired by high levels of bacteria and elevated levels of the nutrients nitrogen and
phosphorous, and that the designated uses are not fully supported due to levels of these pollutants
in these waterways.
Section 303(d) of the Federal Clean Water Act (CWA) requires States to develop a list (303(d)
List) of waterbodies for which existing pollution control activities are not sufficient to attain
applicable water quality criteria and to develop Total Maximum Daily Loads (TMDLs) for
pollutants or stressors causing the impairment. A TMDL sets a limit on the amount of a pollutant
that can be discharged into a waterbody and still protect water quality. TMDLs are composed of
three components, including Waste Load Allocations (WLAs) for point source discharges, Load
Allocations (LAs) for nonpoint sources, and a Margin of Safety (MOS).
DNREC listed St. Jones River on several of the State’s 303(d) Lists and proposes the following
Total Maximum Daily Loads regulation for nitrogen, phosphorous, and enterococcus bacteria.
2.0 Total Maximum Daily Loads (TMDLs) Regulation for St. Jones River
Article 1 - The total nitrogen load from the two point source facilities in the watershed (Dover
McKee Run and Reichhold Chemicals) shall be limited to 9.2 pounds per day. The nitrogen
waste load allocation for Dover McKee Run will be 7.7 pounds per day and for Reichhold
Chemicals will be 1.5 pounds per day.
Article 2 - The total phosphorous load from the two point source facilities in the watershed
(Dover McKee Run and Reichhold Chemicals) shall be limited to 0.37 pounds per day. The
phosphorous waste load allocation for Dover McKee Run will be 0.24 pounds per day and for
Reichhold Chemicals will be 0.13 pounds per day.
Article 3 - The enterococcus bacteria load from the two point source facilities in the watershed
(Dover McKee Run and Reichhold Chemicals) shall be limited to 1.67E+09 colony forming
units (CFU) per day. The enterococcus bacteria waste load allocation for Dover McKee Run
will be 1.1E+09 CFU per day and for Reichhold Chemicals will be 5.7E+08 CFU per day.
Article 4 - The nonpoint source nitrogen load in the entire St. Jones River watershed shall be
reduced by 40 percent from the 2002-2003 baseline level. This shall result in a yearly-average
total nitrogen load of 860.3 pounds per day.
Article 5 - The nonpoint source phosphorous load in the entire St. Jones River watershed shall be
reduced by 40 percent from the 2002-2003 baseline level. This shall result in a yearly-average
total phosphorus load of 63.01 pounds per day.
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Article 6 - The nonpoint source enterococcus load in the entire St. Jones River watershed shall
be reduced by 90 percent from the 2002-2003 baseline level. This shall result in a yearly-
average enterococcus load of 1.63E+11 CFU per day.
Article 7 - Based upon water quality model runs and assuming implementation of reductions
identified by Article 1 through Article 6 above, DNREC has determined that, with an adequate
margin of safety, water quality standards will be met in the St. Jones River.
Article 8 - Implementation of this TMDLs Regulation shall be achieved through the development
and implementation of a Pollution Control Strategy. The Strategy will be developed by DNREC
in concert with the Tributary Action Teams, other stakeholders, and the public.
10 DE Reg. 1037 (12/01/06)
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Appendix B - Tributary Action Team Letter to Secretary Hughes
January 18, 2007
The Honorable John A. Hughes
Delaware Department of Natural Resources and Environmental Control
89 Kings Highway
Dover, DE 19901
Dear Secretary Hughes:
The St. Jones Tributary Action Team respectfully submits the attached document as the recommended
Pollution Control Strategy for achieving the 2006 Total Maximum Daily Load required nonpoint source
nutrient load reductions and bacteria reductions for the St. Jones Watershed.
In June 2005, a steering committee was convened by the Delaware State University Cooperative
Extension and the Delaware Department of Natural Resources and Environmental Control. The
committee of about twenty people included local farmers, homeowners, master gardeners, business
owners, city, state and municipal planners and homebuilders. Initially the committee was charged with
creating an issue booklet that outlined three approaches for how to address water pollution in the St.
Jones. In February and March 2006, the Team held public forums to gather opinions from local citizens
regarding these approaches and which ones best represented their interests. The forums also served as a
way to educate the public about water quality concerns and encourage their involvement in the team.
Following the forums, guiding principles were written to summarize the input from the public forums and
provide the foundation on which the Team would develop its recommendations. In April 2006, St. Jones
Tributary Action Team was formed including members of the original steering committee and new
members from the community. After extensive education, both in the classroom and in the field, the
Team wrote its recommendations during meetings from September 2006 to January 2007. The attached
document is the outcome of these efforts.
We hope you find our recommendations for the Pollution Control Strategy to be effective in reducing
nutrient loads and bacteria in the St. Jones Watershed. Please keep us informed as the process continues.
Sincerely,
Cynthia C. McAllister
Facilitator for The St. Jones Tributary Action Team
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Participants DNREC Support Personnel
Gena Acker Jennifer Bowman
Jim Acker Kathy Bunting-Howarth
Rhiannon Box Jennifer Campagnini
Jeff Carlson Lyle Jones
Zach Carter
John Clendaniel
Randy Cole
Janelle Cornwell
Kelly Crumpley
Tracie Daddio
Mark DelVecchio
Lee DiSalvo
David Edgell
Patrick Erbland
Bobby Fifer
George Fisher
Jim Galvin
Glenn Gladders
Ed Ide
Annie Jacobs
Samuel Johnson
Cherie Jones
Bill Kroen
Beth Krumrine
Mike Krumrine
Dyremple Marsh
John Miller
Bill Murray
Jon Nichols
Suzanne Omrod-Schmidt
Mike Petit de Mange
John Pugh
Stephen Shaeffer
Drew Sharp
Janice Truitt
Ralph Truitt
Josh Turner
Marianne Walch
Chris Ward
Chris Zimmerman
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St. Jones Tributary Action Team
Pollution Control Strategy
Overall Recommendation
The Team recommends that there be a fully funded staff position to coordinate watershed
projects.
Open Space Recommendations
I. Buffers
A. The Department should develop a St. Jones Watershed buffer overlay map to ensure
buffers are in place throughout the watershed to improve water quality. This overlay
map should be developed in cooperation with local municipalities and used to
coordinate efforts among jurisdictions and must consider urban (developed) and rural
(undeveloped) settings.
B. A 100 foot vegetated or forested riparian buffer zone should be required within the
watershed for all water bodies. However, this requirement should not apply to
agricultural lands. Measurement should be from the edge of the bank of the water
body landward.
C. If a buffer cannot be placed within a project or an existing buffer area is reduced during
development, the lack of the buffer should be mitigated. The Department should
develop the criteria for compensation and a selection of alternatives which can be used
as compensation. The criteria should consider both urban and rural settings and
provide equivalent nutrient reductions (1:1 ratio).
D. Vegetation within the buffer should be made up of “recommended plantings” of
native species. However, the type of plantings should not be mandated. A minimum
density of plantings is required to ensure water quality benefits.
E. Buffers should be maintained in perpetuity and should be managed to maintain
water quality benefits. Use of easements in this regard is encouraged.
F. In all common areas, boundary signs should be installed to identify the buffer and
its boundary. However, signs are not required on private property.
G. The Team recommends that buffer compliance should be the responsibility of the Kent
County Conservation District during its planning and review process. The Department
should initiate discussions with the District about this recommendation. (However if a
stormwater utility is implemented, as the Team recommends, buffer compliance could
be linked into this effort.)
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Open Space Recommendations (continued)
II. Open Space
A. Land maintained as passive or active open space under local ordinances or codes should
be managed to minimize nutrient loading.
B. Home Owners’ Association members should be educated on caring for open space in
their neighborhoods to minimize nutrient loading and encourage natural habitat.
III. Education
A. A comprehensive watershed assessment and protection program should be implemented
state-wide to provide a framework for coordinating multiple watershed protection efforts.
This program should promote the integration of local, state and federal water quality
improvement efforts and improve public education and participation in all aspects of
watershed protection.
B. A comprehensive education plan to teach the public how their actions impact the St.
Jones Watershed (and specifically water quality) should be implemented. Some
suggestions include:
1. Public service announcements
2. Brochures distributed through real estate agents, retailers, and school children
3. Face to face education with Home Owners Associations and other organizations
4. Coordination with Master Gardeners’ education
5. Integration of education into the state and local permitting processes
6. Education on purchasing of water conserving appliances
7. Education of school children on water quality
8. Education for farmers to recommend appropriate use of buffers on lands in
production. (Possibly coordinate with Nutrient Management
Commission)
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Wastewater Recommendations
I. Sewer Transmission Systems should be repaired to reduce infiltration and inflow during
wet periods.
II. Onsite Wastewater Treatment and Disposal Systems (OWTDSs) should be inspected
and pumped out regularly to reduce nutrient loading of the groundwater. Compliance
with current regulations should be promoted.
III. Cesspools and seepage pits should be eliminated systematically as these wastewater
systems discharge nutrients and bacteria directly into the groundwater. The septic
inspection and maintenance program should help locate and eliminate them.
IV. If it is physically and legally available (as defined by the regulations governing the
design, installation and operation of OWTDSs), OWTDSs should be removed in growth
zones and connected to Kent County Wastewater Treatment Facility. Through the
inspection and maintenance program, failed systems should be identified for connection
to sewer, if available, or replacement, if not.
V. If an OWTDS fails, it will be identified through the inspection and maintenance program.
To obtain a new permit, the system will be required to use the best available “new
technology” to achieve required nutrient reduction targets for the watershed.
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Stormwater Recommendations
I. General
A. A stormwater utility should be implemented to generate a stable source of funding
for stormwater management within the watershed.
B. Stormwater Best Management Practices (BMPs) should be designed to reduce
nutrients according to TMDLs.
C. Local municipalities, Kent County Conservation District and Kent County should
meet to determine how to limit the addition of new impervious cover to less than 20%
of the watershed to conserve water quality. During the review process, the use of
pervious surfaces should be encouraged.
D. Local municipalities and Kent County should adopt regulations to promote Low
Impact Development (LID) in new construction and redevelopment. The team
recommends the use of tax incentives where possible.
E. A stormwater inventory should be conducted to identify areas where stormwater
retrofits would effectively reduce sediment and nutrients.
F. Since Home Owners Associations are critical for successful stormwater BMP
maintenance, there should be a governmental agency charged with making sure the
Associations are functional. In the Association by-laws, there should be a
requirement for stormwater education.
II. Education
A. An education program for Home Owners Associations should be developed for
stormwater BMP maintenance. Educational resources should be provided and ideally,
face to face education that stresses the organizations’ responsibility. Topics should
include: proper use and application of fertilizer and use of salt and sand during
periods of snow.
B. The Smartyard Program should be implemented in the watershed to assist
homeowners in planting native landscaping to conserve water and reduce fertilizer and
pesticide use.
C. Corporate environmental stewardship should be encouraged to provide corporations
with the technical expertise to help them better manage and enhance their land
through the use of native species and the restoration of natural habitat.
D. The Department should coordinate efforts with non profit watershed organizations
(e.g., St. Jones Greenway Commission, Silver Lake Commission, etc)
E. A comprehensive education program should be developed for the urban and suburban
sector on issues of water quality and urban nutrients. This may include:
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1. Working with the University of Delaware to revise soil testing so they are more user
friendly.
2. Educating homeowners on the importance of cleaning up pet waste, water
conservation, lawn care (and the use of fertilizers) and proper disposal of grass and
yard waste.
3. Working with the Delaware Nutrient Management Commission and the Master
Gardeners to provide education and programs for homeowners on lawn and garden
best management practices.
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Agriculture Recommendations
I. Recommended agriculture best management practices
The Team recommends that Best Management Practices (BMPs) for agriculture be
encouraged and supported. New funding sources should be sought and financial incentives
should be increased. The following BMPs, in particular, should be considered for additional
funding:
A. Cover crops to protect soil when row crops are not being grown. This practice helps
retain nitrogen in the soil for the next crop which reduces fertilizer costs to the farmer.
B. Grassed filter strips and grassed buffers to trap sediments in surface runoff and take up
excess nutrients.
C. Grassed waterways to transport surface runoff away from cropland without causing
erosion or flooding and protect and improve water quality.
D. Riparian forested buffers to reduce nutrient losses from upland acres and to reduce
sediment bound phosphorous from entering waterways.
E. Water control structures to increase the water level in the field which allows for
denitrification and reduces dependency on irrigation.
F. Pasture stream fencing to reduce the bacterial and nutrient loads to a water body.
G. Nutrient Management Planning: The Team is aware that as of 2007 all lands (over
10 acres) that have nutrients applied must be in compliance with the Nutrient
Management Act. The Nutrient Management Act requires all farms over 10 acres or
with 8 animal units to establish a nutrient management plan, which includes the use of
fertilizers and the fate of manure. Because Nutrient Management Plans reduce excess
cropland nutrients, the Team strongly recommends that the Nutrient Management
Commission ensure full compliance of the Nutrient Management Act.
H. Manure relocation has removed significant amounts of excess manure from the Inland
Bays and Nanticoke watersheds, consequently removing excess nutrients from those
watersheds. Thus, the Team recommends that all excess manure (per the Nutrient
Management Plan) be removed from the St Jones Watershed. If funds are lacking, the
Team recommends that additional state and federal funds be applied to the manure
relocation program.
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Agriculture Recommendations (continued)
I. Although it is difficult to quantify the nutrient reductions associated with
Structural BMPs (such as manure structures, pads, sheds and composters) the
Team recommends that these BMPSs be as fully funded as possible because
they insure proper management and storage of manure and dead animals so
that they do not become an additional problem for the environment.
II. Education
A. Farmers should be educated on the above mentioned BMPs.
B. The public should be educated on practices to discourage resident nuisance
waterfowl.
C. Farm land and natural resource area preservation should be encouraged and
promoted.
New funding sources should be sought and financial incentives should be increased.
The public should receive education on current programs, including:
1. Farmland Preservation Act
2. Kent County Transfer Development Rights
3. Non-profit environmental groups
4. Easements and donations
III. Other
A. New funding sources should be sought and financial incentives should be
increased for wildlife habitat and wetland restoration.
B. The State should partner with the Army Corps of Engineers (and other
appropriate parties) to pursue restoration of the St. Jones Watershed.
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Appendix C - Public Talk –Real Choices
Introduction
Public issues are complex, ‘wicked’ problems. Poverty, education, land-use, environment and
others are issues not easily resolved. Delaware for example is a national leader in welfare reform,
education reform, land use legislation and the environment but those close to these issues know
the reforms are stalled locally and nationally. Why? We believe a lack of public engagement in
creating public policy is a fundamental reason. We have become a technocratic society, resulting
in the public abdicating it’s role as participants in creating public policy to a bureaucracy. It is
generally accepted by both parties, the public and bureaucracy, that the public does not have the
capacity” to work through complex issues. It is incumbent on those who work with the public to
create a better way to engage the public in creating sustainable public policy.
A Common Model for Public Engagement
One model found frequently when public agencies need public input is the “workshop” model.
The model begins with a selection of a small group of people, a citizens advisory committee or
“blue ribbon” panel. The group, usually with the help of the public agency, goes through an
education process, writes a report, and delivers it to the agency. The agency holds “tell and sell”
workshops, followed by public hearings and possible promulgation of regulation. The model
more often than not fails to give the public a significant chance to participate in policy formation,
resulting in disillusionment, and failed policy. Both the public and public agencies need and
deserve a better way to work together that produces sustainable decisions.
A Preliminary Approach
Losing Ground: What Will We Do About Delaware’s Changing Landscape? A series of issue
forums or public conversations, throughout the state in 1996, introduced deliberative dialogue to
340 Delawareans. Deliberative Dialogue is a conversation in which people, the public, weigh the
cost and consequences of their thinking and make choices based on their deliberations. It was
the first time for many where in a public meeting citizens had the opportunity to both listen and
talk to each other in an environment conducive to learning. It was not a public hearing where
comments are taken for the record or workshop with information presented by experts.
Comments after the forums indicated citizens would come out and discuss issues of importance,
people want a way to engage issues personally, and will engage each other in questioning and
learning. The results of Losing Ground appear to indicate the public wants a better model to
engage public issues. It is from the conversations heard from citizens that participated in Losing
Ground that the model Public Talk – Real Choices emerged.
Why Develop Another Model?
Two major citizen efforts assisted by DNREC, the Inland Bays Monitoring Committee and the
Citizens Advisory Committee of the National Estuary Program, produced action plans for
restoration of the Inland Bays. The plans are very similar to each other, in fact a matrix of the
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two plans attempts to avoid duplication of effort (CCMP, 1995). Citizens spent over nine years
of work between the two plans. Both plans emerged from a visioning model asking the questions
“What do we want the Bays to look like?” and “How can we get there?” The action plans are
broad recommendations that lack specific suggestions for implementation. There remains a
tremendous amount of frustration from citizens who have engaged in one or the other or both of
the Bay protection efforts (Citizen Advisory Committee Minutes, 1997) and the public agency,
DNREC, whose mission is to preserve and protect the natural resources of Delaware. Both
parties want the same thing, healthy bays, and still there is no solution or commitment.
A Caveat
There is a difference between then and now and that is TMDL’s are regulations. Both the Inland
Bays Monitoring Committee and the National Estuary Program were voluntary. The regulatory
community can argue TMDL’s are promulgated regulation that demand action through pollution
control strategies. That is true to a point. The State met the requirement of the settlement by
establishing the TMDL’s for the watershed. The pollution control strategies are self-imposed
requirements. Without significant public engagement in creating strategies that potentially
impact all residents in the watershed, the strategies will die in the political arena. By taking time
on the front end, and working through a truly public process, the State stands to gain more in the
end product of a sustainable public policy.
The Model: Public Talk – Real Choices
The purpose of Public Talk – Real Choices is to move formulation and creation of a major public
policy decision from a public agency to the public for dialogue and deliberation. Public Talk –
Real Choices builds on what happened in Losing Ground forums. Using deliberative dialogue as
the core, Public Talk goes further by engaging the public in learning about the issue, weighing
the costs and consequences of what is important through dialogue with each other, and coming to
public judgment. The model consists of six steps; Organization of Work Team, Education, Issue
Framing, Evaluation of the Issue Framework, Public Forums/Choice Work, Recommendations.
Model Components
Organization - is a structural component that brings the public agency and public, the work
team, into agreement as to what needs to be accomplished. Without preliminary understanding
and agreement by both parties, the effort will fail.
Education - further enhances this arrangement by building upon the knowledge of the process
shared in the organizational discussions and then adding information necessary to frame the
issue. A good portion of technical information will come from the public agency e.g. the Inland
Bays Whole Basin Assessment Report.
Issue framing - is the critical piece necessary for public engagement. Issue framing lays out in
an organized fashion for public consumption three or four choices. The framework must be
unbiased, represent the under girding values embedded in policy choices and articulate the basic
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costs and consequences of the choices. It should represent the voices of all impacted by the
issue.
The framework sets the stage for our conflicting motives – those things we consider valuable and
that pull us in different directions when we have to decide how to act. The issues need to be
stated in ways that compel the public to make their views known.
Evaluation of the Framework - This piece gives insight into how successfully the teams framed
the issue. The use internal deliberation, focus groups, etc. enhances the success of the
framework. For successful public deliberation all voices need to heard within the framework.
The choices must be neutral and offer a positive approach for issue resolution.
Public deliberation - is the cornerstone of Public Talk – Real Choices. A significant
representation of the public must deliberate the issue. This occurs through successful planning
and selection of venues for forums. The forums must result in some form of common ground for
action.
Recommendations - The work teams sift through and analyses the public voice they heard from
the forums. From this public voice the work team develops the pollution control strategies.
Why This Model?
National Issues Forums
National Issues forums are “town meetings” that bring people together to deliberate “wicked
problems,” problems that won’t go away, with the help of moderator. The medical analogy of a
broken arm versus diabetes describes wicked problems. The broken arm can be set and heals.
Diabetes requires life -changing alterations. Participants use an issue book that offers three to
four choices for resolution. Within the choices are basic values, cost and consequences of the
choice. With the help of a moderator the public works through the choices, by looking at four
things: What is valuable? What are the costs and consequences of the choice? Where is the
tension? Where is there common ground for action? Participants must consider “It’s not what I
want to do but what we ought to do."
Why Are These Models Effective?
The Harwood Group in a report Meaningful Chaos- How People Form Relationships with Public
Concerns, found nine factors necessary for public engagement.
Connections – People tend to enlarge rather than narrow their views of public concerns, making
connections among ideas and topics that society tends to fragment.
Personal Context – People relate to concerns that “fit” with their personal context, moving
beyond self-interest to what is meaningful
Coherence – People want to hear the whole story. They want to understand what it means.
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Room for Ambivalence – People do not immediately see black and white. They want a gray
area to question, discuss, test ideas, and become comfortable with their opinions.
Emotion – Too many processes try to remove emotion from decision making. Emotions are
necessary to sustain relationships with public concerns.
Authenticity – People and information must “ring true”.
Sense of Possibilities – People really want something to happen and they might play a role in it.
Catalysts – Everyday people, not just experts and elite, are critical in helping people form
relationships with public issues.
Mediating Institutions – Places where people come together to talk and act on public concerns.
(Harwood, 1993)
National Issues Forums and Public Talk – Real Choices adhere to these tenets.
The Facilitator Team
Public Talk – Real Choices uses a neutral, third party facilitator. By using a neutral, third party
as the facilitator, the facilitator becomes an advocate for the process (Kaner, 1996). Third party
facilitation avoids the perception of bias that can occur when the facilitator is personally
associated with the issue.
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Bibliography
Archie, Michele. 1995. Framing Issues: Building a Structure for Public Discussions. Kettering
Foundation, Dayton, Ohio.
Boyte, Harry C. 1989. Commonwealth: A Return to Citizen Politics. New York: The Free Press.
Boyte, Harry C. and Nancy N. Kari. 1996. Building America: The Democratic Promise of Public Work.
Philadelphia: Temple University Press.
Delaware Department of Natural Resource and Environmental Control. 1998. Inland Bays Advisory
Committee. Delaware Department of Natural Resources and Environmental Control, Dover, Delaware
Dukes, Francis E. 1996. Resolving Public Conflict: Transforming Community and Governance. New
York: Manchester.
Fishkin, James S. 1995. The Voice of the People: Public Opinion and Democracy. New Haven: Yale
University Press.
Hesselbein, Francis et al. 1998. The Community of the Future. San Franisco: Jossey-Bass.
Hustedde, Ronald J. 1994. Community Issues Gathering. University of Kentucky Cooperative Extension
Fact Sheet. Lexington, KY
Ilvento, Thomas, et al. 1995. Losing Ground: A Public Conversation About Delaware’s Changing
Landscape. University of Delaware Cooperative Extension Fact Sheet. Newark, DE
Kaner, Sam. 1996. A Facilitator’s Guide to Participative Decisions. Philadelphia: Friends Press.
Martin, John H. 1998. An Analusis of Nutrient Utilization Efficiency by Agriculture in Delaware’s Inland
Bays Drainage Basin. Final Report submitted to Center for the Inland Bays: Nassau, Delaware
Mathews, David. 1994. Politics for People: Finding a Responsible Public Voice. Chicago: University of
Illinois.
Peters, Scott J. 1998. Extension Work as Public Work: Reconsidering Cooperative Extension’s Civic
Mission. St. Paul: University of Minnesota Extension Service
Schwarz, Roger M. 1994. The Skilled Facilitator: Practical Wisdom for Devloping Effective Groups. San
Francisco: Jossey-Bass.
Ratnor, Shanna. 1997. Emerging Issues in Learning Communities. Yellow Wood Associates Inc. St.
Albans, Vermont.
Topkiss Foundation. Resource Book For Community Wide Study Circles. 1998. Hartford, CT. Topkiss
Foundation.
Watershed Assessment Section, Division of Water Resources. 1998 Draft – Total Maximum Daily Load
(TMDL) Analysis for Indian River, Indian River Bay, and Rehoboth Bay, Delaware. Delaware
Department of Natural Resources and Environmental Control, Dover, Delaware.
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Wheatley, Margaret J. 1994. Leadership and the New Science: Learning About Organization from an
Orderly Universe. San-Francisco: Berrett-Koehler.
Yankelovich, Daniel. 1991. Coming to Public Judgement: Making Democracy Work in a Complex World.
New York: Syracuse University Press.
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Appendix D - BMP Nutrient Reduction calculations
BMP NUTRIENT REDUCTION CALCULATIONS
Calculating the Required Total Maximum Daily Load Reductions Based on Land-use
The Total Maximum Daily Load (TMDL) for receiving waters in the St JonesSt Jones calls for a
40% reduction in total nitrogen (TN) and a 40% reduction in total phosphorus (TP) (EPA, 2005).
The baseline period for this TMDL was established from 2002 land use data used to determine
the acreages of each of the following land uses: Urban, Agricultural, Forest, Wetland, Water,
and Other, which includes land uses like rangeland and barren land. The results are tabulated
below (Table 1).
Table 1. 2002 St Jones St Jones Watershed Land-use Acreages
Total
Urban Agricultural Forest Wetland Water Other
acreage
17,410 24023 5082 8643 1354 1824 58, 346
In order to calculate nutrient loads from non-point pollution sources, the land use acreages from
Table 1 were combined with the land use loading rates in Table 2, which were determined based
on results of research conducted by experts in the St Jones Watershed to produce daily nutrient
loads according to land use, as displayed in Table 3.
Table 2. Land-use Loading Rates
TN (lbs/acre/yr) TP (lbs/acre/yr) Source
Developed 6.2 0.73 St Jones TMDL, 2006
Agriculture 8.0 3.21 St Jones TMDL, 2006
Grasslands 8.0 0.73 St Jones TMDL, 2006
Forests 6.3 2.56 St Jones TMDL, 2006
Wetlands 0.0 0.00 St Jones TMDL, 2006
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Table 3. 1997 St Jones Watershed Land-use Based Loads
Urban Agricultural Forest Wetland Water Range Other Total
TN 296 523.7 87.41 0 0 9.13 31.2 947.43
(lbs/day)
TP
34.82 48.05 35.57 0 0 0.83 2.84 122.11
(lbs/day)
I. Baseline load calculation for land-use type by reduction area:
Using the land use loading rates listed in Table 2, the nutrient loads coming from non-point
sources during the baseline period are determined using the equation below. It should be noted
that the grassland loading rate was used to determine the loads from the “Other” land use
category.
Loading rate for
Nutrient load Acreage of
specific land-use
Lbs/yr & lbs/day = specific land- X
(lbs/acre/yr)
(Table 3) use (Table 1)
(Table 2)
EX: TN load for urban land use:
6,200 lbs TN/yr
6.2 lbs or
TN load = 1,000 acres X
TN/acre/yr
= 16.99 lbs
TN/day
II. Required TMDL reduction on a land-use basis:
The annual and daily nutrient load reductions needed from non-point sources to achieve the
reductions outlined in the TMDL are calculated using the following equation. For the St Jones
Watershed, the TN load needs to be reduced by 934.8 lbs/day and the TP load by 40.29 lbs/day.
In order to achieve these reductions, the best management practices (BMPs) discussed in the
Pollution Control Strategy must be implemented.
Required TMDL
Baseline load Percent
reduction = (lb/day)
X
reduction
(lb/day)
EX: TN TMDL required load reduction:
Required TMDL
947.43 lbs 37.9 lbs
reduction = TN/day
X 40% = TN/day
(lb/day)
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Onsite Wastewater Disposal System (OWTDS) BMP Calculations
In order to determine the nutrient loading by OWTDS to groundwater, local watershed data and
knowledge has been utilized.
Twelve OWTDS existing near Red Mill Pond in Lewes, Delaware were monitored in 1993
(DNREC, 1994). The average total phosphorus concentration of the effluent from these systems
was 15.7 mg/L, while the total kjeldahl nitrogen (TKN) concentration was 58.5 mg/L and the
nitrate/nitrite concentration was 0.8 mg/L. The total nitrogen concentration of the average
effluent from this study was summed to equal 59.3 mg/L. Conversations with professionals in
this industry have suggested that 50.0 mg/L is a more appropriate value of TN concentrations in
on-site effluent and this value has been used in subsequent calculations.
Small systems, which are typical individual household systems, have flows less than 2,500 gpd.
The average design flow for individual residential OWTDS is 221 gpd.
The nutrient load to the watershed from drain fields can be established by determining the
product of the above concentrations and respective flow rates.
Robertson and Hartman (1999) found that 85% of the total phosphorous in the effluent will be
retained in the vadose zone or the unsaturated soil above the water table, most of which is within
12 inches of the drain field (Gold and Sims, 2000). Initial calculations presented by the
Department, also based on the Red Mill Pond study, assumed that 87% of TP and 52% of TN is
assimilated in the soils once the effluent leaves the septic tank.
The final loading rates from OWTDS to groundwater can be determined using the following
equations:
Small systems (<2,500 gpd):
[Conc. (mg/l) x (lb/453,592 mg)] x [(221 gal/system/day) x (3.7854 l/gal)] x (1-soil assimilative capacity)
Thus, the OWTDS nutrient loading rates to groundwater in the St Jones Watershed are:
• 0.052 lbs TN/system/day and 0.004 lbs TP/system/day for individual small systems less than
2,500 gpd
I. Connecting OWTDS to Sewer Districts
Since 1992, 11 OWTDS (septic) systems are reported to have been removed from the St Jones
watershed by connecting homes and businesses to sewer districts ((New Castle County Special
Services, written communication, 2009) and (Town of Middletown, written communication,
2009)). These systems have been connected to sewer districts that dispose of their waste at spray
irrigation facilities.
Reductions for systems that are connected to plants that use spray irrigation receive a 90%
efficiency since nutrients remain in the ecosystem (DNREC Groundwater Discharges Section,
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personal communication, 2003). The nutrient load reductions are calculated using the following
equation.
Nutrient load OWTDS loading
# of eliminated Reduction
reduction = rate X
OWTDS
X
efficiency
(lbs/day) (lbs/system/day)
EX: TN reduction due to OWTDS connection:
TN load 0.052 lbs
11 eliminated 0.52 lbs
reduction = TN/system/ X
OWTDS
X 90% = TN/day
(lbs/day) day
II. Holding Tank Inspection and Compliance Program
On average, holding tanks have a 2,800 gallon capacity. Metcalf and Eddy (1991) reported that
holding tanks typically hold 2,596 gallons of effluent and 204 gallons of septage (solids). Recent
observations from the compliance program indicate volumes of 2,464 gallons of effluent and 336
gallons of septage volume. The average effluent concentrations previously discussed (50.0 mg
TN/L and 15.7 mg TP/L) have been used to determine the effluent loads from holding tanks.
The nutrient load contribution from septage in holding tanks will be determined using the
nutrient concentrations in septage from holding tanks (600 mg TN/L and 250 mg TP/L), as
reported in Wastewater Engineering, Third Edition (Metcalf and Eddy, 1991). The nutrients
removed per holding tank pump-out are shown in Table 5, calculated using the above
concentrations.
Table 5. Nutrient Reductions from a Holding Tank Pump-Out
Total N Total P
(lbs/tank/pump-out) (lbs/tank/pump-out )
Holding Tank Effluent 1.03 0.32
Holding Tank Septage 1.68 0.70
Total 2.71 1.02
Effluent:
Nutrients Removed (lbs/tank/pump-out) =
Conc. (mglL) x (lb/453,592 mg) x (2,464 gal/tank) x (3.7854 l/gal)
Septage:
Nutrients Removed (lbs/tank/pump-out) =
Conc. (mglL) x (lb/453,592 mg) x (336 gal/tank) x (3.7854 l/gal)
There is 1 holding tank currently in the St Jones Watershed. Each time a holding tank is
pumped, 2.71 lbs TN and 1.02 lbs of TP do not enter the St Jones.
Initially, the Department assumed that tanks are pumped-out 16 times per year. The Small
Systems Branch, Groundwater Discharges Section of the Division of Water Resources
determined this number to be high. Records from the Holding Tank Compliance program
indicate that on average, holding tanks are pumped-out about 12 times per year, or once a month
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(DNREC Groundwater Discharges Section, personal communication, 2001). Thus, this latter
figure was used for subsequent calculations to determine the annual load reduction using the
equation below.
Nutrient load Reduction rate
12 pump-
reduction = (lbs/tank/pump X
outs year
X # of tanks
(lbs/yr) -out)
EX: TN reduction due to Holding Tank Pump Out:
TN load 2.71 lbs 32.52 lbs TN/yr
12 pump-outs
reduction = TN/tank/pump- X
year
X 1 tank = or
(lbs/day) out 0.09 lbs TN/day
III. OWTDS Pump-outs
Using a GIS, an analysis was conducted that determined as of March 2009, there were 6244
OWTDS in the St Jones Watershed.
Waste haulers usually deliver waste to the nearest wastewater treatment plant. According to
information from the Wilmington Treatment Facility, 53 tanks were pumped from the St Jones
Watershed in 2001. In addition, it was estimated that 47 tanks from the St Jones Watershed were
pumped from the Kent County Treatment Facility in 2001 because they could not give exact
information on the number of systems pumped. This equals 100 tanks being pumped out a year
in the St Jones Watershed based on a 1,000 gallon tank capacity. By assuming that after three
years, a septic tank will contain 750 gallons of effluent and 250 gallons of septage (volumes
based on local inspector-hauler observations), and using the concentrations of effluent and
septage given above, the effluent load reductions per system achieved by a pump-out program
are shown below in Table 6.
Table 6. Nutrient Reductions from an OWTDS Pump-Out
Total N Total P
(lbs/system/pump-out) (lbs/system/pump-out)
OWTDS Effluent 0.31 0.10
OWTDS Septage 1.25 0.52
Total 1.56 0.62
Effluent:
Nutrients Removed (lbs/system/pump-out) =
Conc. (mg/l) x (lb/453,592 mg) x (750 gal/system) x (3.7854 l/gal)
Septage:
Nutrients Removed (lbs/system/pump-out) =
Conc. (mg/l) x (lb/453,592 mg) x (250 gal/system) x (3.7854 l/gal)
The load reduction in the water column achieved by this practice can be calculated using the
following equation.
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EX: TN reduction due to OWTDS pump-out program:
IV. OWTDS Performance Standards
Wastewater pretreatment technologies exist to remove nitrogen, phosphorus, or both from
wastewater prior to soil dispersal of the effluent. A consultant hired by the Department
evaluated the performance efficiencies of these technologies then recommended performance
standards for OWTDS in Delaware and several levels of performance efficiencies for nitrogen
and phosphorus (The On-Site Wastewater Corporation, draft written communication, 2003).
A recommendation in the St Jones Pollution Control Strategy surrounding small septic systems
requires new and replacement subdivisions in areas outside of sewer districts to be equipped with
systems that can reach standards such as “Performance Standard Nitrogen 3” (PSN3) to reduce
nutrients. Technologies that can achieve PSN3 will produce a 50% reduction of effluent TN
concentration when compared to the TN influent concentration. The nutrient load reduction can
be determined using the following equation.
Nutrient load OWTDS loading # of existing
Reduction
reduction = rate X OWTDS in X
efficiency
(lbs/day) (lbs/system/day program
EX: TN reduction due to upgrading to alternative systems:
TN load 0.052lbs
1,034 27.1 lbs
reduction = TN/system/ X
OWTDS
X 50% = TN/day
(lbs/day) day
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Stormwater BMP Calculations
I. Stormwater BMPs
Several types of structures that treat stormwater runoff are used throughout the St Jones
Watershed. The efficiencies associated with common stormwater BMPs are listed in Table 7. In
order to calculate the load reduction to the receiving water body, the calculation outlined below
is used. The nitrogen urban loading rate is 15 lbs/acre/yr, while the phosphorus loading rate is
0.5 lb/acre/yr (Ritter and Levan, 1992).
Table 7. Stormwater BMP Reduction Efficiencies (Chesapeake Bay Program, 2009)
BMP TN (%) TP (%)
Wet ponds 30 50
Dry pond (extended detention) 5 10
Infiltration (swale, infiltration basin/trench) 50 70
Biofiltration 50 70
Filtering Practice (bioretention) 50 70
Nutrient load Total drainage area Urban
Reduction
reduction = treated by X loading rate X
efficiency
(lbs/day) structures (acres) (lbs/acre/yr)
EX: TN reduction due to wet ponds:
TN load 5,861.43 26,376 lbs TN/yr
15 lbs
reduction = acres treated X
TN/acre/yr
X 30% = or
(lbs/day) on average 72 lbs TN/day
II. Potential Future Stormwater Retrofit Projects:
It is anticipated that an additional 1272 acres of urban area in the St Jones watershed will be
retrofitted in the future. It is difficult to project, however, the exact number and type of
treatment structures that will be used. The majority of stormwater practices currently in use in
the watershed are wet and dry ponds, while infiltration, biofiltration, and filtration structures
together are less likely to be used. It is unlikely that these same proportions will be used in
future retrofit projects since the construction of ponds will require a considerable amount of
space and it may be unfeasible to create these structures in areas that are already developed.
Because of this, it has been assumed that future retrofits will be more equitable with equal
implementation of ponds and other practices.
The load reductions achieved from the stormwater BMPs currently on the ground have been
summed into two categories, “Dry Ponds” and “Infiltration Practices.” These values were
divided by the total area treated in each category to calculate nutrient reduction rates. For “Dry
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Ponds,” the reduction rates are 0.31 lbs TN/acre/yr and 0.0.7 lbs TP acre/yr, while the reduction
rates for “Infiltration Practices” are 3.10 lbs TN/acre/yr and 0.51bs TP acre/yr.
The potential future loading reduction to the stream as a result of retrofitting 1,722 acres of urban
lands can thus be determined using the equation below.
Nutrient load Reduction Future
Acres of
reduction = rate X
retrofit
X percent use
(lbs/day) (lbs/acre/yr) of practice
EX: TN reduction from future stormwater infiltration Practices:
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Open Space Calculations
I. Grassed Open Space
Grassed open space is treated as a land use change from agricultural cropland to grassed open
space. Thus, the acres that undergo change will receive a lower loading rate. The loading
reduction is calculated as follows.
EX: TN reduction due to open space provisions:
II. Riparian Buffer
It is assumed that for every one acre of land where riparian buffers are employed, that two
upland urban acres are treated. This approach is similar to the practice employed by the
Chesapeake Bay Program (CBP, 1998). The efficiencies for nutrient load reductions are an
average of the range presented by J.T. Sims and J.L. Campagnini (written communication,
2002). Thus, the agreed efficiencies are as follows:
Forested buffers: TN-- 62% and TP-- 62%
For these BMPs, the actual acre of the practice will be treated as a land use conversion and the
reduction efficiencies will be applied to two acres of affected upland for each acre of practice.
EX: TN reduction due to UDC riparian buffer requirements:
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Agriculture BMP Calculations
The following calculations are provided as a result of the Agricultural Pollution Control Strategy
Workgroup’s efforts in gathering the best available science for nonpoint source pollution
prevention from agricultural sources. The workgroup began meeting in April 2002 to gather the
best available data on nutrient efficiencies for various agricultural best management practices.
These recommendations and calculations are based on averages over several years from different
studies and are dependent on weather conditions, soil type, crop production intensity, excess
manure generation, topography and other site specific conditions. In addition, a lag time likely
exists between practice implementation and benefit observation, which cannot currently be
estimated since all nutrient fate and transport processes are not well understood at this time.
I. Cover Crops
Nitrogen reduction efficiencies for cover crops were calculated using a weighted average method
for each year. The data used in this calculation came from ranges of cover crop TN efficiencies
for several plant species presented by J.T Sims and J.L. Campagnini (written communication,
2002). The Workgroup chose a single efficiency, often an average of the range, for the
commonly used species in Delaware (Table 8). The United States Department of Agriculture,
National Resource Conservation Service provided information on each cover crop planted in the
2008-2009 season in the St Jones Watershed (shown in bold). This information was used to
calculate a weighted average efficiency of the crops planted, determined to be 54.9% for the
2008-2009 season. It should be noted that with this approach, the efficiency will change from
year to year, depending on the acreage of each cover crop species planted. For TP, the
Workgroup referred to the best professional judgment presented by Sims and Campagnini, which
was “less than 5%,” and will be considered for these purposes as 4.9%. The nutrient load
reduction is calculated with the equation shown below.
Table 8. Cover Crop Efficiencies for TN
Cover Crop Species Work Group BMP Efficiency (%)
Barley 70
Hairy Vetch 6
Annual Rye 65
Cereal Rye 54.5
Oats 55
Wheat 55
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Nutrient load Agricultural
Acres of cover Reduction
reduction = loading rate X
crops
X
efficiency (%)
(lbs/yr) (lbs/acre/yr)
EX: TN reduction due to 3,144.80 acres of cover crops:
TN load 13,812 lbs TN/yr
8 lbs 3,144.80
reduction = TN/acre/yr
X
acres
X 54.9% = or
(lbs/day) 37.8 lbs TN/day
II. Ponds, Grassed Waterways, Grassed Filter Strips, Wildlife Habitat
The Conservation Reserve Program (CRP) practices are treated as a land use change from
agricultural cropland to grassed waterways or grassed filter strips, or wildlife habitat. Thus, the
acres that undergo change will receive a lower loading rate. Since the Conservation Reserve
Enhancement Program (CREP) was implemented, any new grass filter strips created will be
treated as a CREP practice and will receive a reduction calculated by the method described later.
The loading reduction is calculated as follows.
EX: TN reduction due to 1,413.80 acres of wildlife habitat:
III. Filter Strips, Forest Buffers, Riparian Buffers, Wetlands
The Conservation Reserve Enhancement Program (CREP) practices (CP21-grass filter strips) are
assumed to act as grassed buffers. CREP practices (CP22-riparian buffer, CP23-wetland
restoration and CP3A-hardwood trees) are all assumed to act as forested buffers. The
Workgroup assumed that for every one acre of land where these practices are employed, that two
upland acres are treated. This approach is similar to the practice employed by the Chesapeake
Bay Program (CBP, 1998). The efficiencies for nutrient load reductions are an average of the
range presented by J.T. Sims and J.L. Campagnini (written communication, 2002). Thus, the
agreed efficiencies are as follows:
Grassed buffers: TN-- 46% and TP-- 54%
Forested buffers: TN-- 62% and TP-- 62%
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For these BMPs, the actual acre of the practice will be treated as a land use conversion and the
reduction efficiencies will be applied to two acres of affected upland for each acre of practice.
EX: TN reduction due to 30.8 acres of CREP filter strips:
IV. Field Border
Nutrient reductions from field borders are treated as Conservation Reserve Program (CRP)
practices. These practices are treated as a land use change from agricultural cropland to
grassland habitat. Thus, the acres that undergo change will receive a lower loading rate. It is
important to note that field borders are measured in feet and must be converted to acres.
EX: TN reduction due to 18,299 ft of wildlife habitat:
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V. Critical Area Planting
Critical area planting is a BMP that controls soil erosion and results in phosphorus reductions
since phosphorus adsorbs to soils. The critical area planting practice is considered a hot spot
BMP and is applied to areas in fields where soils are severely eroding. Soil loss is based upon
NRCS values. The critical area planting practice decreases soil erosion from these highly
erodible areas from 10 tons per acre per year to 0.5 tons per acre per year, or a soil loss reduction
of 9.5 tons per acre per year. To calculate the reduction from this practice, the acreage of the
practice is multiplied by the soil loss reduction value, the amount of readily desorbed phosphorus
(0.23 mg P/kg soil) (Sims et al. 1994), and conversion factors.
TP load Reduction in soil Readily desorbed
Conversion
reduction = Acres X loss X phosphorus X
factors
(lbs/yr) (9.5 tons/ac/yr) (0.23 mg P/kg soil)
EX: TP reduction due to 35.80 acres of critical area planting:
0.16 lb
TP load TP/yr
35.8 9.5 tons/ 0.23 mg 2000 lbs/ kg
reduction = acres
X
ac/yr
X
P/kg soil
X ton
X
10^6/mg
= or
(lbs/yr) 0.004 lb
TP/day
VI. Conservation Tillage
Conservation tillage is a BMP that controls soil erosion by modifying tillage practices on a farm
field which reduces sediment and hence phosphorus losses from the tilled field. Soil loss is
again based upon NRCS values. Conservation tillage practice can lower soil erosion to 1.5 tons
per acre per year from approximately 4.1 tons per acre per year for conventional tillage, or a soil
loss reduction of 2.6 tons per acre per year. To calculate the reduction from this practice, the
acreage of the practice is multiplied by the soil loss reduction value, the amount of readily
desorbed phosphorus (0.23 mg P/kg soil) (Sims et al. 1994), and conversion factors.
TP load Reduction in soil Readily desorbed
Conversion
reduction = Acres X loss X phosphorus X
factors
(lbs/yr) (2.6 tons/ac/yr) (0.23 mg P/kg soil)
EX: TP reduction due to 4,182.20 acres of conservation tillage:
5 lb TP/yr
TP load
4,182.20 2.6 tons 0.23 mg 2000 lbs/ kg or
reduction = acres X
ac/yr
X
P/kg soil
X ton
X
10^6/mg
= 0.01 lb
(lbs/yr)
TP/day
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VII. Nutrient Management Plans
To reduce agriculture’s impact on water quality, Delaware legislated a nutrient management
program in 2002 to oversee nutrient applications within the State. In 2003, 20% of farmers
applying nutrients to 10 acres or more or those who manage 8 or more animal units within the
state were required by the Nutrient Management Act to create and submit a nutrient management
plan (NMP) to the Nutrient Management Commission (NMC). Each year between 2004 and
2007, another 20% of eligible farmers were required to have NMPs, with 100% implementation
by January 1, 2007. These plans are routinely updated and modified to meet the nutrient needs
of the future cropping rotations and practices.
The Delaware Conservation Partnership (DCP) conducted a survey in July 2007, after the
deadline requiring all eligible farm operations to have a plan, to evaluate nutrient management
planning in the state. The DCP consists of the Delaware Conservation Districts, the Natural
Resources Conservation Service, and the Delaware Department of Natural Resources and
Environmental Control, and strives to work together to meet the needs of Delaware Farmers by
providing cost-share programs, educational opportunities, and nutrient management planning
services. The survey was designed to inform those programs by identifying gaps in information
and education and opportunities to spend cost-share dollars more effectively. In short, the
purpose of the project was to make nutrient management work better for farmers in Delaware.
The surveys were sent out to everyone who has been certified by the Nutrient Management
Program- 2,034 people in all. The Delaware Conservation Partnership received 698 responses-
about a 34% response rate. The following is the breakdown of responses among different sizes
of farms:
1-10 acre farms – 9% response rate
11-99 acre farms – 29% response rate
100-499 acre farms – 25% response rate
500 + acre farms – 20% response rate
Animal only farms – 10% response rate
Responses varied only slightly among different farm sizes and types, with the exception of
whether or not nutrient management provided an economic benefit to their farm. Larger farms
and those whose plans were written by a private consultant were most likely to agree that
nutrient management provides an economic benefit to their operation. Small farms, animal
operations and those whose plan was written by someone on staff were least likely to agree.
The surveys indicated that fertilizer application rates have decreased the most among farmers
who till at least 500 acres, while manure applications have decreased most among farmers who
till between 11 and 99 acres. When fertilizer application rates are evaluated by county, Sussex
farmers reduced the rate of N and P applications the most, Kent reduced N applications the least,
whereas New Castle deceased P applications the least.
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Table 5. Change in Fertilizer and Manure Application Rates Due to 2002 Nutrient
Management Law
County Farm Acres % Change in % Change in % Change in
nitrogen phosphorus manure
fertilizer fertilizer application
applications applications
Kent 173,808 13.4 26.9 5.4
New Castle 66,981 16.0 20.1 13.6
Sussex 269,464 18.5 37.1 24.2
Weighted
16.4 31.4 19.9
Average
The efficiencies based on the DCP survey can be compared to other estimates of nutrient
management planning effectiveness. An Agricultural Workgroup was established to gather the
best available science on nonpoint source pollution prevention for agricultural sources. The
Workgroup operated off the basic assumption that if fewer nutrients are being applied to the
land, fewer nutrients will be lost to Delaware’s water bodies. From this premise, the Workgroup
determined nutrient efficiencies for various agricultural best management practices including the
effectiveness of nutrient management planning.
Initially, the Workgroup addressed the impact of nutrient management planning (NMP) in the
Inland Bays and Nanticoke watersheds from a study by McGowan and Milliken (1992). This
study listed the reductions associated with various management practices observed over a three
year period, with a total of 103,736 lbs TN reduced by 2,328 acres under nutrient management
planning. To determine a general NMP TN reduction, the Workgroup decided that the
reductions and acreage associated with manure allowance and cover crops should be removed
from further calculations since reductions for both of these items are determined separately and
all NMPs will not include manure relocation. This subtraction gave a total of 1,224 acres of
nutrient management planning and a load reduction of 70,136 lbs of TN, resulting in a reduction
rate of 57.3 lbs/acre per 3-year planning cycle. McGowan and Milliken (1992) reported that the
TN application rate prior to the introduction of NMPs was 280 lbs/acre per 3-year planning
cycle, so NMPs produced a 20.5% reduction in TN. This estimate falls in the lower range
reported by the State of Maryland (MDNR, 1996), which was 20-39% for nitrogen. The
corresponding phosphorus range reported by the Maryland DNR was 9-30%. However, due to
the absence of a report similar to the McGowan and Milliken study in Delaware for P, there is
not enough information available to determine an appropriate reduction efficiency to apply to
NMPs for phosphorus in these two watersheds.
In the St Jones watershed, one representative farm within the watershed volunteered to allow the
Workgroup to analyze the nutrient data they routinely gather. This particular farm tracks
nutrient application rates to each crop field within a database that goes back to 1999, prior to the
passing of the Nutrient Management Act. The data were separated into two groups, pre-Nutrient
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Management Plans (NMPs) (1999-2002) and post-NMPs (2003-2004), and entered into
Statgraphics Software for statistical analysis. It was determined that there was a statistically
significant difference between the mean application rates at the 95% confidence level for
nitrogen. The average nitrogen application rate decreased by 12.4% from the pre-NMP level and
this value will be taken as the NMP reduction efficiency; unfortunately, no reduction could be
calculated for phosphorus from this data.
At the request of the NMC, Sims et al. (2008) conducted extensive nutrient mass balance
calculations for the State for the years 1996 through 2006. They calculated both input/output and
management–oriented mass balances for nitrogen and phosphorus. The Sims et al. (2008)
approach included calculations for manure relocation and estimates of biological fixation of
nitrogen by leguminous crop and clearly demonstrated that fewer nutrients are being applied to
Delaware’s cropland.
DNREC Watershed Assessment Section (WAS) has worked with the NMC and the University of
Delaware Cooperative Extension to determine the impact of the Nutrient Management Act on the
amount of nutrients applied to Delaware’s agricultural fields. Using an input-output type analysis
using fertilizer sales data and crop yields, WAS determined that on a state-wide basis, 47% less
nitrogen and 62% less phosphorus has been applied to Delaware’s cropland. Both the WAS and
Sims et al. (2008) approach produced similar results.
The DCP values, which are based on the reductions in nutrient applications actually reported by
Delaware farmers, fall within the range of efficiencies determined by the numerous other
methods and data sets discussed above. As a result, DNREC proposes to use the DCP
efficiencies to estimate the reduction in nutrient application rates resulting from the promulgation
of the Nutrient Management Law.
There were 12,583.65 acres of nutrient management planning in the St Jones Watershed in 2008.
The Chesapeake Bay Program (2009) has aggressively established nitrogen and phosphorus
reductions associated with various urban and agricultural best management practices including
nutrient management planning. The Program applies a 13% reduction to nitrogen and a 27%
reduction to phosphorus for every acre of cropland that has a nutrient management plan. Those
nutrient reductions were applied to every acre of cropland in the St Jones watershed. Using the
Bay program reductions TN and TP efficiencies and the agricultural loading rate reported earlier,
the annual and daily load reductions due to these acres can be calculated as follows.
TN load 21,587 Reduction 22450.5 lbs
Agriculture
TN/yr
reduction = acres under X loading rate X efficiency = or
(lbs/yr) NMPs (8 lbs TN/acre/yr) (13%) 61.5 lbs TN/day
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Appendix E - BMP Cost Calculations
This document describes the cost-effectiveness of urban and agricultural best management
practices (BMPs) that reduce nutrients. Although the costs for Total Phosphorus (TP) removal
appear high, they may be thought of as ancillary benefits of Total Nitrogen (TN) removal. In
addition, they show the relative cost effectiveness of TP removal by each practice.
On-Site Wastewater Treatment and Disposal System (OWTDS) BMP
Cost Calculations
Connecting OWTDS to Sewer Districts
According to DNREC’s Financial Assistance Branch (personal communication, 2007), the
average cost of constructing a sewer system is $8,500 per equivalent dwelling unit (EDU). In the
future, this cost is expected to increase to $10,000/EDU. The debt service, or cost of financing
these systems, at roughly an average 2% rate is currently $1,867/EDU and will be $2,194/EDU
for future septic eliminations and sewer connections. Additionally, system owners must pay for
the final septic system pump-out, crushing and filling the tank, and the connection costs
associated with building the lateral line running from the building to the right of way. These
three expenditures together run approximately $1,000/EDU. Finally, operation and maintenance
(O&M), including repair fees, of roughly $200 per EDU per year will also be added to these
values for an average 20 year lifespan of a connection (DNREC Financial Assistance Branch,
personal communication, 2007) (Table 1).
Table 1. OWTDS Elimination Costs
Past Conversions Future Conversions
Construction of sewer system $8,500/EDU $10,000/EDU
Debt service $1,867/EDU $2,194/EDU
Additional expenditures $1,000/EDU $1,000/EDU
Operation and Maintenance (over $4,000/EDU $4,000/EDU
20 year lifespan)
TOTAL $15,367/EDU $17,194/EDU
Holding Tank Inspection and Compliance Program
The cost of pumping-out a 2,800 gallon holding tank averages around $250 per system per
pump-out (DNREC Small Systems Branch, personal communication, 2007). As a result of the
holding tank inspection and compliance program, they have been shown to be pumped-out
roughly 12 times a year. This information reveals that the owner of a single holding tank will
spend $3,000 each year. In addition to this cost, there is an annual inspection fee of $60 per
system (DNREC Small Systems Branch, personal communication, 2007), so that the total
expenditure for holding tank inspection and compliance is $3,060/system/year and over a 20 year
lifespan the cost is $61,200/system.
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OWTDS Pump-outs
The cost of pumping-out OWTDS ranges from $185-200 per system, with an average cost of
$192.50 per system (DNREC Small Systems Branch, personal communication, 2007). It is
proposed that septic systems be pumped once every three years and inspected during that time
period as well. These proposed inspections will be performed by licensed inspectors at an
estimated cost that ranges from $200 to $400 with an average cost of $300 at the time of pump-
out (DNREC Small Systems Branch, personal communication, 2007). The total cost of the
OWTDS inspection and compliance program will cost the system owner $164.17/system/year
and over a 20 year lifespan this equals $3,283.33/system.
OWTDS Performance Standards
Licensed installers and members of DNREC’s Small Systems Branch (personal communication,
2007) revealed that the installation of best available technologies (BATs) to existing small
(<2,500 gallon per day (gpd)) OWTDSs for advanced nitrogen removal would cost between
$3,500 and $6,000 per system with an average installation of $4,750. These technologies are
believed to last for approximately 20 years. These technologies require a service contract by a
certified service provider with an estimated annual cost that ranges from $150 to $300, with an
average cost of $225/system/year. In addition, the systems will still require pump-outs, which
costs $64/system/year (DNREC Small Systems Branch, personal communication, 2007), and
they will need periodic mechanical parts repaired, estimated to cost $50/system/year and the
electrical cost of running the systems is likely to also cost about $50/system/year (DNREC
Financial Assistance Branch, personal communication, 2007). Taking all of this into account,
the total cost of this strategy is $12,530/system.
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Stormwater BMP Cost Calculations
Wet and Dry Ponds
Typical costs for retention basins were retrieved from Chapter 6.0, “Costs and Benefits of Storm
Water BMPs,” of an EPA on-line document (EPA, 1999). In this document, it states that a
retention basin treating a 50-acre residential site in 1999 costs about $100,000, such that the cost
per unit area was $2,000/acre. All values reported in the document need to be divided by an
adjustment factor to account for regional differences. Delaware falls in Region 2, which has a
0.90 adjustment factor (EPA, 1999). Thus, retention basins in Delaware in 1999 cost
approximately $2,222.22/acre. Using the average annual federal inflation rate for the time period
of 1913-2007 (3.42%), the capital cost of Delaware retention basins in 2009 is $2,982/acre. To
this value, the annual operation and maintenance costs over a 25 year lifespan must be added.
Operation and maintenance costs for retention basins can range from 3-6% of the construction
costs (EPA, 1999). We have used an average value of 4.5% which is $134.19 and applied this to
the regionally adjusted construction cost over the 25 year lifespan. The total cost for this
strategy is $6,336.75/acre.
Infiltration Structures
The 1999 construction costs of infiltration trenches and infiltration basins treating 5-acre
commercial sites were averaged to represent the range of infiltration structures utilized as
stormwater BMPs throughout Delaware. These costs were $45,000 for trenches and $15,000 for
basins (EPA, 1999), which equates to $9,000/acre and $3,000/acre, respectively, and averages
$6,000/acre. Once adjusted for the regional variability in cost (0.90 factor), and inflated to 2009,
this value becomes $8,946.67/acre treated by infiltration structures. Annual O&M costs for
infiltration structures range anywhere from 1-20% of the construction cost (EPA, 1999), and
average 10.5%. This produces an annual O&M cost of $939.40/acre/yr which when calculated
over a 25 year lifespan and added to construction costs equals $32,431.68/acre.
Filtering Practices
Cost data for filtering practices was obtained from a publication of the Environmental and Water
Resources Institute of the American Society of Civil Engineers (ASCE, 2001). Since filtering
practices treat runoff from pavement and impervious areas, the construction cost was reported for
the early 1990s as $10,117.36 per impervious acre. The 2009 cost can be estimated using the
average federal inflation rate and the early 1990s values to be $17,008.41/acre. The O&M costs
typically range from 11-13% of the construction costs (EPA, 1999), which on average, is
$2,041.01/acre/year. Calculating the O&M costs over a 25 year lifespan and adding to
construction costs provides a total cost of $68,033.64/acre.
Biofiltration
The EPA on-line document reported that the construction costs for biofiltration devices in 1999
were $60,000 for a 5-acre commercial site (EPA, 1999), which equates to $12,000/acre. This
value must also be divided by the 0.90 adjustment factor to account for regional cost differences,
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which yields $13,333.33/acre, and then adjusted to the 2009 value, $17,893.33/acre. The annual
O&M costs range from 5-7% of the construction cost (EPA, 1999). When using 6% as the
average, annual O&M costs $1,073.60/acre/year and are further calculated over a 25 year
lifespan. Thus, total costs for biofiltration equals $44,733.33/acre.
Table 2. Stormwater BMP Costs
Wet and Infiltration Filtering Practices Biofiltration
Dry Ponds Structures
Construction/acre $2,982.00 $8,946.67 $17,008.41 $17,893.33
O&M 4.5% 10.5% 12% 6%
(% of Construction)
Annual O&M per $3,354.75 $23,485.00 $51,025.25 $26,840.00
acre over a 25 year
lifespan
Total Cost/acre $6,336.75 $32,431.67 $68,033.66 $44,733.33
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TABLE OF CONTENTS
Introduction ................................................................................................................................................................1
Saint Jones River History ......................................................................................................... 1
Existing Watershed Conditions................................................................................................ 4
Watershed Baseline Assessment............................................................................................. 5
Sub-watershed Delineation ..................................................................................................... 6
Executive Summaries of Watershed Projects ...............................................................................................8
Silver Lake Sub-Watershed .......................................................................................................... 8
Sub-Watershed Implementation Strategy ................................................................................................... 11
Strategy ..................................................................................................................................... 11
Monitoring ................................................................................................................................. 13
Sub-Watershed Management Opportunities.............................................................................................. 25
Introduction ............................................................................................................................... 25
Silver Lake sub-watershed projects ........................................................................................... 26
Current Projects..................................................................................................................... 26
Partner Projects ..................................................................................................................... 34
Future outlook of the Silver Lake sub-watershed ..................................................................... 36
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INTRODUCTION
The St. Jones River is located in Kent County, Delaware and hosts the state capital, the City
of Dover. The City of Dover has a large influence on the St. Jones River, its tributaries, and
the entire Watershed of which it drains. Silver Lake, a man-made lake formed by a dam in
the St. Jones River, is the largest body of water in the City, and has attracted residents and
visitors to enjoy its benefits. The growing number of visitors and increasing development of
land have taken their toll on the Lake. In 1986, the Silver Lake Commission (Commission)
was formed following the recommendation of Dover’s City Council. On August 27, 1990, by
request from then-Mayor Jack Richter, the Commission was officially adopted as an advisory
committee to the City Council and City staff.
Since then, the Commission has worked to improve the condition of the Lake and provide a
forum for public involvement on issues related to the Lake. Commission members seek
ways to improve the Lake’s water quality, wildlife habitat, open space and park
opportunities, and water-related activities through participation and coordination with
other government bodies and institutions (Dover, 1990).
The purpose of this document is to provide the Silver Lake Commission and its partners
with a strategy for implementing water quality-improvement projects that influence the
ecological condition of Silver Lake. A prioritized list of potential Best Management Practice
(BMP) opportunities with the greatest cost-benefit ratio to Silver Lake shall serve as a
resource to the Commission for future project planning.
In addition to this document, other resources are available for planning goals outside of this
document’s reach, such as wildlife habitat improvement, open space creation, or
recreational activity implementation.
SAINT JONES RIVER HISTORY
The St. Jones River is dammed at Silver Lake and winds down 10mi towards the Delaware
Bay passing through commercial, residential, and agricultural areas along the way. The
watershed of the St. Jones River drains the upland area of the River in addition to its
tributaries including Fork Branch, Maidstone Branch, Cahoon Branch, McKee Run, and
Dover Creek. 57,643 acres of land drain into the St. Jones River, ultimately emptying into
the Delaware Bay (Rogerson, Jacobs, & Howard, 2010).
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Figure 1. Location of the St. Jones River Watershed in central Delaware.
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Land use activities can characterize a particular region, such as a watershed, and provide a
snapshot of the area showing how it is being used. Comparisons between land use data
from different points in time provide insight into how the landscape has changed and what
trends have started to appear. Land use data allows planners and land managers to make
informed decisions regarding the future development and protection of a watershed.
Historically, the watershed land use characteristics were dominated by agriculture. In
today’s landscape, while agriculture is still a dominant land use, it is quickly being replaced
by development, more specifically, residential development. The National Land Cover
Dataset (NLCD) in 2007 shows almost 70% of the watershed as agricultural or developed
land. Information from the NLCD in 1997 compared to 2007 shows a 6.5% decrease in
farmed land and a 6% increase in developed land (Table 1). This suggests an almost direct
conversion of farmland to developed land. As stated in the “Technical Background Report,
Silver Lake Watershed” by Earl Shaffer, “urbanization through the conversion of land to
permanent impervious surfaces such as streets and houses, represents an irreversible
impact on the watershed” (Shaffer, 1989). Proper planning is necessary to prevent costs
associated with clean-up efforts downstream of development; it is also necessary to protect
ecologically important areas that play an integral part in the health of the watershed.
A more detailed description of the history of the St. Jones River and watershed can be found
in the DNREC report “Technical Background Report, Silver Lake Watershed.”
Table 1. Land use changes for the St. Jones River watershed between 1997 and 2007
(Rogerson, Jacobs, & Howard, 2010).
Land Use Category 1997 (%) 2007 (%) 10-year % Change
Developed 25.5 31.5 +6.0
Recreational 1.4 1.8 +0.4
Farmed 44.5 38.0 -6.5
Forest 9.8 8.4 -1.4
Wetlands 14.9 15.1 +0.2
Water 2.1 2.7 +0.6
Beaches/Sand <1.0 <1.0 0
Extraction or
1.8 2.4 +0.6
Transitional
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Figure 2. Land Use in the St. Jones Watershed in 2007 based on NLCD land use
categories.
EXISTING WATERSHED CONDITIONS
Under the Federal Clean Water Act, the State’s Department of Natural Resources and
Environmental Control (DNREC) has the responsibility of monitoring the water quality in
the St. Jones Watershed and other watersheds in Delaware. DNREC analyzes water samples
for impairments that could compromise the integrity of the waterways and the many uses
they provide. Impaired waterways that do not meet the specified State and Federal
standards are listed on the national 303 (d) list. If a waterway is on the list, under the
Federal Clean Water Act, DNREC is required to develop a Total Maximum Daily Load
(TMDL) to remediate the water quality of the watershed. A TMDL was developed for the St.
Jones Watershed to address the impairments found in all of the Watershed segments.
The State of Delaware’s 2010 Combined Watershed Assessment Report (305(b)) and
Determination for the Clean Water Act Section 303(d) List of Waters Needing TMDLs
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identifies 8 listed water segments: 2 tidal segments of the St. Jones River, 3 freshwater
stream segments, and 3 freshwater lakes or ponds. Reasons for listing include bacteria,
dissolved oxygen (DO), PCBs, nutrients, dioxin, mercury, DDT, arsenic, biology, and habitat
(DNREC, April 2010). The most probable source of these pollutants is from Non-Point
Source (NPS) pollution. TMDLs are currently in place to reduce pollutants and eventually
remove water segments off the impairment list (303(d)). TMDLs should be used as a guide
for prioritizing water quality improvement projects and incorporated into future land
planning and management decisions.
WATERSHED BASELINE ASSESSMENT
A baseline assessment of the entire St. Jones Watershed (Watershed) was completed by
Duffield Associates, Inc. (Duffield) in October 2008. With help from volunteers, Duffield
identified and evaluated potential pollution control opportunities in the sub-watersheds
and urban areas that would improve water quality and prevent impairment. In total, 158
opportunities were identified, scored, and prioritized, including 26 WMWQ technology
opportunities and 132 upland opportunities. An additional five potential corridors for
preservation/land management opportunities were also identified.
The baseline assessment indicated various sources and types of water quality impairment.
Duffield then identified several practices that could reduce pollution in the Watershed and
selected sites to evaluate the practices. “Upland target areas included opportunities such as
retrofitting existing sites with revised best management practices (e.g. bioswales,
bioretention) and select neighborhood and hotspot sites that could increase water quality
protection by using different site or land management practices. The upland sites were
ranked from high to low priority. The WMWQ sites were evaluated for six technologies,
which focused on wetland/floodplain restoration and creation, buffers, infiltration, and
preservation. The WMWQ sites were scored and then ranked by Watershed-wide, sub-
watershed, technology, and site. Table 5 shows Watershed-wide rankings for total WMWQ
scores and individual WMWQ technology scores for each site evaluated” (Duffield
Associates, Inc., October 2008). (Christina Tributary Action Team and Water Resources
Agency, 2007; F.X. Browne, 1988; DNREC, City of Dover, and Advisory Committee, 1996)
Projections for future impervious cover are increasing in all four sub-watersheds (Table 2).
The Silver Lake sub-watershed is projected to have the greatest amount of total area of
imperviousness (5,122.4 acres), while the Tidbury Creek sub-watershed is projected to
have the greatest increase of imperviousness relative to total land area (27.6%).
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Table 2. Sub-Watershed Potential Future Land Use Statistics and Existing Protected Lands
SUB-WATERSHED DELINEATION
For the purposes of this report, the four sub-watersheds identified by the Duffield Report
(Duffield Associates, Inc., October 2008) will be used and referenced throughout this
strategy.
The Duffield report created a map that delineates the sub-watersheds of the St. Jones
Watershed based on existing geospatial data (Figure 3). The sub-watershed delineation
map is used to more accurately report data and recommendations in each sub-watershed.
The sub-watershed boundaries reported by Duffield are as consistent as possible with those
reported by DNREC. The sub-watersheds include: Isaac Branch, Silver Lake, St. Jones River,
and Tidbury Creek.
Water bodies within each sub-watershed include:
Silver Lake- Fork Branch, Penrose Branch, Maidstone Branch, Cahoon Branch,
Puncheon Run, Upper St. Jones River, Silver Lake
Isaac Branch- Isaac Branch, Allabands Mill Stream, Almhouse Branch
St. Jones- Lower St. Jones River
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Tidbury Creek- Tidbury Creek, Red House Branch, Newell Branch, Voshell Pond,
Derby Pond
Figure 3. Sub-watersheds of the St. Jones River Watershed delineated.
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EXECUTIVE SUMMARIES OF WATERSHED PROJECTS
SILVER LAKE SUB-WATERSHED
From its inception, the Silver Lake Commission (Commission) worked towards improving
Silver Lake and its associated drainage area, the sub-watershed within the St. Jones
Watershed. Through partnerships with state, county, local governments, and non-
regulatory organizations, the Commission has completed numerous successful projects. It is
also continuously adapting and improving projects to meet the challenges of difficult
problems that arise in Silver Lake (Lake). The following lists identify past projects
completed or attempted, and the background behind each project.
i. Silver Lake.
1. Biological stimulant. A new, proprietary product came recommended to
DNREC staff by officials who used it to treat algal growth in stormwater
ponds and water treatment facilities in California and Virginia. The product
was designed to alter the nutrient ratios of carbon, nitrogen, and
phosphorus, and encourage the growth of naturally occurring bacteria that
is usually suppressed by overabundant algal blooms. At the time, algal
blooms outcompeted natural bacteria for the available nutrients in the Lake.
DNREC staff, alongside City of Dover personnel, decided to test this
biological formula in Silver Lake and other smaller lakes and ponds in
Delaware. It was applied to Silver Lake during the summer of 1996 every
two weeks above the causeway. Ideally, the currents move some of the
product below the causeway to improve algae conditions throughout the
entire Lake. Using this method, the annual cost to the City is approximately
$15,000. If an additional application needs to be applied below the
causeway to achieve the desired results, the cost can increase to $25,000,
plus the cost of additional supplies and personnel time.
The results of the application of the biological stimulant were somewhat
inconclusive. During the summer of 1996, above average rainfall events
occurred in the area of Silver Lake. Silver Lake saw decreased amounts of
algal blooms, however, it is uncertain whether that was a result of the
stimulant, or the lake’s higher, rain-induced flushing rates. City and DNREC
staff had hoped to apply the stimulant the following summer to compare
results between separate seasons; however, the company supplying the
product had closed before the next round of testing could be completed
(Tyler, 2011) (DNREC, City of Dover, and Advisory Committee, 1996).
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2. Aeration. Aeration of Silver Lake was a recommendation from the report by
F.X. Browne Associates and also in a discussion paper by DNREC, the City of
Dover, Kent County, and an advisory committee, (“Options for the Protection
and Improvement of Silver Lake”) and was considered an option to increase
the dissolved oxygen content of the Lake waters and enhance vertical
circulation (DNREC, City of Dover, and Advisory Committee, 1996). Ideally,
this would improve circulation of the water column, increase habitat for
aerobic organisms, reduce or eliminate fish kills, reduce internal nutrient
loadings, decrease blue-green algae populations, and improve water column
oxygenation. This technique was described as being best suited for shallow
lakes where temperature stratification is minimal. However, the costs
associated with the amount of materials and equipment necessary for
aerators to operate effectively in Silver Lake were high. There were also
concerns regarding boat traffic in the lake and whether recreationalists
using the lake would damage the aerators and associated components.
Later, DNREC scientists advised against the use of aerators because of the
determination that it would re-suspend phosphorus into the Lake (Tyler,
2011) (Edgell, 2011).
3. Alum. From the dismissal of the use of aerators grew the interest in using
alum to alleviate the nutrient-related problems in the Lake. As suggested by
the F.X. Browne report alum would bind phosphorus at the sediment-water
interface and prohibit phosphorus from entering back into the water column
(F.X. Browne, 1988). At the time, the technique was new and little was
known about the lake characteristics needed for the process to be effective.
Its use in coastal plain ecoregions, where shallow water ponds and lakes are
common, is not feasible due to the short hydrologic residence time and
sediment disturbance from physical and biological factors. Boating on the
Lake is a popular activity and wave action from the boats would resuspend
particulate phosphorus and particulate aluminum. Also, the expense to
purchase alum alone is high (Greene, 2011).
ii. Silver Lake Sub-watershed
1. Stormwater retrofit at Delaware State University. In both the F.X.
Browne study and “Options” report, recommendations for the creation of
“forebays” at several inflow points into Silver Lake to try and trap sediment
and other pollutants before washing into the Lake. One site where this was
completed is located at the intersection of State College Road and N. College
Road on the property of Delaware State University in Dover. The
constructed forebay treats approximately 150 acres of commercial and
industrial land, including 1.2 miles of the nearby 6-lane highway which is
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one of the most traveled in the state. The project consists of a forebay area
designed to capture the majority of the sediment and anything not captured
there overflows to a shallow wetland area where additional water treatment
can occur. In total, the project area is approximately 3 acres. Funds for the
project came from partners including DNREC, City of Dover, Kent County,
and Kent Conservation District. Additional monies came from DNREC
penalty funds, 21st Century fund, and DelDOT pavement and rehabilitation
funds (Division of Soil and Water Conservation).
2. Dredging of Mirror Lake. Mirror Lake is a shallow body of water
downstream of the Silver Lake dam and adjacent to the intersection of
Loockerman Street and Park Drive in Dover. The lake is tidally influenced by
the St. Jones River and has a tidal range of approximately 1.0 foot. Over time
a sand bar has developed from sediment build-up that is deposited and is
visible at low tide. The City of Dover was interested in the improvement of
Mirror Lake for environmental and aesthetic reasons and asked DNREC staff
for recommendations. Staff from DNREC’s Division of Soil and Water
Conservation performed a bathymetric survey of the Lake in February 1997
and sediment core borings in September 2004 as a preliminary step to
investigate the possibility of dredging to remove the accumulated sediment
and other potential contaminants. DNREC provided two methods of
dredging with cost estimates for each method. Mechanical dredging with
truck haul disposal carried a price tag of approximately $427,500 and
hydraulic dredging with geotubes had a cost of approximately $538,500 at
the time of the estimation in 2007. Insufficient funds for the project halted
any further progress for dredging Mirror Lake. DNREC revisited the topic
again in 2010 by initiating a comprehensive analysis on the original
sediment cores taken in 2004, preparing new cost estimates for dredging, of
$1, 500,000, and speaking with the City of Dover and Silver Lake
Commission about potential alternatives in preparation of the results of the
analysis as the costs for dredging may be too high. DNREC also wishes to
explore less expensive and invasive approaches to addressing the sediment
sand bar, while maintaining the goal of reducing the impact to human and
wildlife health.
Additional recommendations were made by F.X. Browne and the “Options” report, however
only the items listed here have been acted upon thus far.
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SUB-WATERSHED IMPLEMENTATION STRATEGY
STRATEGY
The Silver Lake Commission (Commission) re-evaluated their approach to solving Sliver
Lake’s water quality problems around 2005-2006, following their attempts at using large,
solitary capital improvement project methods. Historically, the water quality problems
facing the Lake were compounded due to many non-point sources discharging into the Lake
untreated. The new approach focuses on a watershed-based method that addresses
pollutant problems before they enter the Lake; in this way, pollutants are captured and
filtered before they can degrade water quality in Silver Lake. This proactive approach
encourages the completion of Best Management Practices (BMPs) throughout the
watershed to alleviate the compounded effect in the Lake. While the BMPs may not capture
all pollutants before entering the Lake, addressing the pollutants before they enter the Lake
will significantly improve water quality.
To jumpstart the new watershed-based approach, DNREC hired Duffield Associates, Inc.
(Duffield) to perform a watershed-wide assessment to identify water quality improvement
projects. Duffield performed a baseline assessment in 2007 and published the “St. Jones
River Watershed Baseline Assessment Technical Memorandum” (Baseline Assessment), in
October 2008, which detailed the results. The information gathered provided the basis for
future project recommendations and included information on Watershed and sub-
watershed characteristics, as well as current and projected watershed conditions, to
determine future issues and impairments. The Baseline Assessment identified potential
pollution control opportunities by using information based on current reports, geospatial
data, current regulations, and field review of actual stream bodies. During the field review,
staff from DNREC, the Center for Watershed Protection (CWP), and Duffield documented
visual cues and other watershed conditions that indicate potential water quality
impairments such as: lack of riparian buffer area; undersized culverts downstream from
development; point source discharge pollutant problems; older developments without
stormwater quality best management practices; uncontrolled stormwater runoff - severe
channel erosion; lack of infiltration basins; isolated wetland loss due to lack of regulations;
and agricultural nutrient loading.
These impairments can be addressed and categorized into two categories “upland
restoration” and Watershed Management Water Quality technologies (WMWQ), (Tyler,
2011) which include: tree planting; additional native landscaping; stormwater pond
maintenance, creation, or bioretention; impervious cover removal; on-site stormwater
management (e.g., rain barrels, rain gardens, green rooftops); creation/restoration of
upland buffers; wetland/Floodplain Creation and/or Restoration; stormwater Infiltration;
stream channel improvements; preservation of streams, wetlands, floodplains, and buffers;
and flood control. In the St Jones Watershed, 26 WMWQ technology opportunities and 132
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upland opportunities (total of 158 opportunities) were identified, screened, scored, and
prioritized in the Implementation Plan as potential projects to improve water quality. The
initial scoring and ranking of selected sites and technologies were conducted based on a
system of weighted factors and scoring parameters established by the project team (DNREC,
Duffield Associates, and CWP). For WMWQ sites, six technologies that focused on
wetland/floodplain restoration and creation, buffers, infiltration, and preservation were
evaluated for each site. The sites were then scored on a scale of 1 to 10 for potential, and
ranked based on a watershed-wide scale, sub-watershed, technology-specific, and
individual sites (Table 3). Upland sites were ranked into high, medium, or low priority
based on screening factors and scoring criteria developed by the project team (Table 4).
The list can be organized according to a certain target area, such as a sub-watershed (Table
5). The majority of pollution control opportunities throughout the entire watershed occur
within the Silver Lake sub-watershed (Table 6).
As part of the final step in the watershed study of the St. Jones River basin, Duffield
prepared “St. Jones Watershed Implementation Plan,” in February 2009 to present
strategies and potential prioritization to achieve the pollution control goals using the
opportunities identified. The Plan examined several methods of implementation strategies
for all of the sub-watersheds found in the overlying St. Jones Watershed (Watershed). This
provides the option for different organizations, such as municipalities, DNREC, Kent County,
or regional groups, to select the strategy that best suits their goals and priorities. The
strategies were broken down into three approaches: ranking, technology, and sub-
watershed. Duffield identifies the sub-watershed approach as the preferred strategy, citing
targeted multi-faceted improvements can have significant impact on water quality
improvement. A sub-watershed strategy is also conducive to various funding sources that
may become available. As part of the Plan, Duffield recommends initiating the sub-
watershed strategy with the Silver Lake sub-watershed, the largest in the entire Watershed.
Silver Lake sub-watershed almost fully encompasses the City of Dover, as well as the
headwaters to the entire Watershed. Activities that take place in the headwaters of any
watershed impact the overall health of the entire watershed. The Silver Lake sub-
watershed is approximately 38.4 mi² (24,576 acres) and has the largest percentage of
urban/commercial/residential area, approximately 31%, and the smallest portion of
protected lands at 3.7% (Duffield Associates, Inc., February 2009). Projections for future
impervious surface are expected to exceed all other sub-watersheds (Table 2, Introduction).
These statistics support the recommendation to focus initial efforts in the Silver Lake sub-
watershed. Additionally, Duffield found this sub-watershed to have the greatest potential
for water quality improvement based on the number of high-ranking projects found in the
field assessment. Duffield found the top five sites for WMWQ technology opportunities in
the entire Watershed within the Silver Lake sub-watershed, as well as twelve upland sites
with high ranks (Figure 4).
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MONITORING
A monitoring plan helps determine the effectiveness of projects implemented throughout
the watershed by measuring pollutant load reductions and water quality. It also important
to track activities for state, federal, and municipalities reporting associated with water
quality and restoration projects. In the Plan, Duffield outlines a monitoring plan with
several important components for determining success. There are different methods
presented in the Plan by Duffield to track progress based on the source of information.
Timeframes associated with each method should also be considered when identifying
appropriate monitoring techniques. It is important to determine an appropriate measure of
success, preferably based on scientific data versus visual or aesthetic indicators, and
educate members of the public in the same manner (Tyler, 2011). The Watershed should be
reassessed on a regular basis (every 5-7 years) to maintain the most accurate data and
determine if current priorities are inline with pre-established priorities. If new issues arise,
refocusing the Watershed Plan may be necessary (Duffield Associates, Inc., February 2009).
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Table 3. Silver Lake sub-watershed total WMWQ technology scores, ranked highest to lowest.
Screening Categories for WMWQ Technologies SILVER LAKE SUB-WATERSHED SITE IDENTIFICATION NUMBERS
12/1
3 18 16 5 8 1 10 7 14 3 6 15 17 19 2 20 9 11 4
Existing Buffer Width 1 4 1 10 4 2 10 4 1 1 1 1 1 1 2 1 7 0 1
Existing Buffer Length 3 3 6 10 6 3 9 6 3 7 3 3 3 3 3 3 4 3 6
Proposed Buffer Width 10 10 10 10 9 10 9 6 9 9 5 6 9 6 9 5 6 5 5
Areal Buffer Protection 10 10 10 10 10 10 10 8 10 10 8 10 10 10 8 10 10 10 8
Surrounding Topography
Upgradient of Stream 4 3 4 4 4 3 4 3 4 3 4 4 4 4 4 4 4 4 4
Proposed Buffer Type 10 10 10 3 7 8 4 10 10 8 8 10 10 3 8 3 6 3 8
CREATION/RESTORATION
OF UPLAND BUFFERS 38 40 41 47 40 36 46 37 37 38 29 34 37 27 34 26 37 25 32
Soil Types Within
Creation and/or
Restoration Areas 8 8 8 3 8 3 3 3 3 6 3 1 1 1 1 1 3 1 1
Approximate Average
Depth of Excavation 9 10 10 7 9 7 7 8 4 1 4 6 3 4 1 4 4 1 1
Soil Relocation 10 10 10 10 10 10 10 9 10 9 9 10 10 10 9 10 5 10 4
Hydrology 9 9 10 9 9 9 7 9 5 2 5 5 5 5 0 5 7 2 2
Location Within
Watershed 10 10 10 10 10 10 7 10 10 10 7 10 7 10 8 10 7 7 10
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Wetland Type/Size 10 10 6 10 8 10 10 10 10 10 10 6 10 6 6 6 2 6 6
WETLAND/FLOODPLAIN
CREATION AND/OR
RESTORATION 56 57 54 49 54 49 44 49 42 38 38 38 36 36 25 36 28 27 24
Soil Types Within
Creation Area 3 2 3 3 1 3 3 2 3 3 4 4 3 4 4 4 3 4 4
Appoximate Average
Depth of Excavation 9 7 10 6 7 7 7 6 4 1 4 6 4 4 1 4 4 4 4
Soil Relocation 10 10 10 10 10 10 10 9 10 9 10 10 10 10 9 10 5 10 4
Permeability 6 6 6 6 6 7 6 6 7 7 7 7 7 7 7 7 6 7 7
Location Within
Watershed 8 8 8 7 8 8 7 8 8 8 7 8 7 8 10 8 7 7 8
Size/Land Use 8 8 3 8 8 8 3 8 8 8 10 4 8 4 4 4 2 4 4
INFILTRATION 44 41 40 40 40 43 36 39 40 36 42 39 39 37 35 37 27 36 31
Access 7 9 7 7 4 7 9 7 7 7 9 7 6 7 7 7 9 7 7
Ownership 5 2 2 2 2 5 2 2 2 2 2 2 2 2 2 2 5 2 5
Likely Approach 7 7 7 7 7 5 7 7 7 7 7 7 7 7 7 7 3 5 3
Stream Length 6 6 4 10 6 8 6 4 6 8 4 6 6 6 8 6 6 6 2
Location Within
Watershed 6 6 6 5 6 6 5 6 6 6 5 6 5 6 8 6 2 5 6
Level of Impairment 8 7 4 7 10 1 7 10 4 4 10 7 4 4 7 4 4 7 4
STREAM CHANNEL
IMPROVEMENTS 39 37 30 38 35 32 36 36 32 34 37 35 30 32 39 32 29 32 27
Existing Preservation 10 10 10 7 7 7 7 7 10 7 7 10 3 10 7 10 7 7 7
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Potential Disturbance
Risk 10 7 7 5 5 8 5 5 7 8 5 7 0 7 5 7 8 5 5
Potential Preservation 10 4 5 5 4 4 4 5 4 4 4 4 0 4 5 4 5 4 5
Location Within
Watershed 2 4 4 4 7 2 4 7 2 7 6 2 6 4 2 2 8 4 2
PRESERVATION OF
STREAMS, WETLANDS &
BUFFERS 32 25 26 21 23 21 20 24 23 26 22 23 9 25 19 23 28 20 19
Flood Storage Need 6 4 7 7 2 7 4 0 4 2 4 4 7 2 6 2 1 6 7
Storage Potential 3 3 2 4 3 4 3 2 3 1 3 1 3 2 3 2 1 2 1
Approximate Average
Depth of Excavation 4 5 5 3 3 4 3 2 2 1 2 1 3 1 0 1 3 1 1
Location Within
Watershed 5 5 5 3 5 5 3 1 5 5 3 5 3 5 4 5 2 3 4
FLOOD CONTROL 18 17 19 17 13 20 13 5 14 9 12 11 16 10 13 10 7 12 13
21 21 21 20 20 19 19 18 18 18 18 16 16 16 16 15 15 14
TOTAL SCORE
227 7 0 2 5 1 5 0 8 1 0 0 7 7 5 4 6 2 6
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Table 4. Screening factors and scoring criteria for upland site evaluations.
Primary Screening
Description Scoring
Factor
>11.5 lb = 30
Combines total impervious area treated with
4.5 - 11.5 lb = 20
Pounds of TN Removal removal efficiency of proposed retrofit. Will
Expected per Year score the drainage area to the retrofit & removal
1.5 - 4.5 lb = 10
efficiency of BMP
<1.5 lb = 0
<15K = 25
15 - 35K = 16
Cost Total retrofit cost
35 - 95K = 8
>95K = 0
Capture >= 0.25" during 0.5" storm
event of off-site runoff = 10
Capture of off-site Whether any off-site runoff is captured and
Capture >= 0.10" during 0.5" storm
runoff treated
event of off-site runoff = 5
No off-site runoff captured = 0
Practice includes soil absorption
(bioretention), infiltration, or retention
= 20
Ability of practice to reduce overall volume of
Practice includes filtering, runoff
Runoff Reduction runoff through infiltration, absorption, runoff
dispersion, or other practice that
capture & reuse, etc.
provides some runoff reduction = 10
Practice does not include these
features = 0
Whether property has current funding, planning Good chance for quick implementation
process underway where retrofit could fit into = 15
larger project, or located next to a sensitive water
Short-term
body (e.g., Silver Lake), 319 potential, dry pond Potential chance for quick
Implementation
conversion, DelDOT projects (less than 6 months) implementation = 7
Retrofit Reconnaissance Inventory (RRI) does No utility conflicts identified = 4
Few Site & Utility Not at this time = 0
not identify utility conflicts at location of
Constraints
practice Utility conflicts identified = 0
Secondary
Description Scoring
Screening
No Aesthetic,Factor
Nuisance, Practice does not include standing water, No issues identified = 1
Safety Issues mosquito habitat, steep drop-offs, unattractive
nuisances, etc. Issues identified =
Exceptional 0
opportunity =3
Outdoor Learning & Whether practice is strategically located on LID promoted = 3
Moderate opportunity = 2
Promotes innovative Practice promotes the concept of decentralized
Community Outreach property and has design features that would be of
practices/LID runoff treatment and reduction
Opportunities interest to students and community LID not necessarily
Marginal promoted
oppportunity =1 =0
17
No opportunity = 0
Practice contains features = 2
Promotes Bacteria Practice contains filtering, desiccation, or other
Removal processes that can remove bacteria
Practice doesn't contain features = 0
Trees planting included = 1
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Table 5. Project ranking of Upland sites located in the Silver Lake sub-watershed.
Project Sub-
Rank Municipality Name
ID Watershed
R19c Silver Lake Dover Dover High School
DE Agricultural
R30a Silver Lake Dover
Museum
Carroll's Corner
R48a Silver Lake Dover
Shop Cntr
R31c Silver Lake Dover Legislative Hall
R41a Silver Lake Dover Holy Cross
R19e Silver Lake Dover Dover High School
DE Tech & Comm
R14c Silver Lake Dover College, Terry
Campus
DE Tech & Comm
R14d Silver Lake Dover College, Terry
Campus
R19b Silver Lake Dover Dover High School
Fairview Elementary
High R29c Silver Lake Dover
School
R8a Silver Lake Dover Super Fresh
R34a Silver Lake Dover Schutte Park
N53 Silver Lake Dover Chatham Cove
N56 Silver Lake Dover Silver Mill
N49 Silver Lake Dover Capitol Green 1
Rodney/ May/Cross/
N78 Silver Lake
Wedge
N36 Silver Lake Dover Woodcrest
Lake Club
N52 Silver Lake Dover
Apartments
Woodbrook/Sherwo
N77 Silver Lake Dover
od
N38 Silver Lake Dover Fairview
N55 Silver Lake Dover
Overlook on Silver
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Lake
N54 Silver Lake Dover East Lake Gardens
N11 Silver Lake Dover Baltray
N66 Silver Lake none Hunter's Pointe
State Police
H505 Silver Lake Dover
Station/Museum
Public Works Yard
H510 Silver Lake Dover
(P2)
City Public Works
H506 Silver Lake Dover
Yard
R13a Silver Lake Dover Modern Maturity
R26a Silver Lake Dover Target
William Henry MS /
R22a Silver Lake Dover Booker T
Washington ES
R8b Silver Lake Dover Super Fresh
Med. R19a Silver Lake Dover Dover High School
R26b Silver Lake Dover Target
R106a Silver Lake ?? Taco Bell
R502a Silver Lake Dover Wawa
Dover Central
R23a Silver Lake Dover
Middle School
Fairview Elementary
R29a Silver Lake Dover
School
Carrolls Corner
R48b Silver Lake Dover
Shop. Cntr
Blue Hen Corporate
R64c Silver Lake Dover
Center
Women's Health
Med. R201a Silver Lake Dover
Center
Frear Federal
R530a Silver Lake Dover
Building
R501a Silver Lake Dover US Gas
R64b Silver Lake Dover Blue Hen Corporate
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Center
R101a Silver Lake Dover City Hall
R13b Silver Lake Dover Modern Maturity
Edgehill Shopping
R25b Silver Lake Dover
Center/State Library
R41c Silver Lake Dover Holy Cross
Blue Hen Corporate
R64a Silver Lake Dover
Center
R108a Silver Lake Dover La Tonalteca
State Police
R505b Silver Lake Dover
Museum
R31b Silver Lake Dover Legislative Hall
St Andrews
R500a Silver Lake Dover
Lutheran Church
Edgehill Shopping
R25c Silver Lake Dover
Center/State Library
R105a Silver Lake Dover Burger King
R510a Silver Lake Dover Harvest House
R26c Silver Lake Dover Target
State Police
R505a Silver Lake Dover
Museum
R31a Silver Lake Dover Legislative Hall
Carrolls Corner
R48c Silver Lake Dover
Shopping Center
R41b Silver Lake Dover Holy Cross
McKee Business
R16c Silver Lake Dover
Park
R102a Silver Lake Dover Merrill Lynch
South Dover
R42a Silver Lake Dover
Elementary School
R43a Silver Lake Dover Bay Court Plaza
N1 Silver Lake Dover Mill Creek
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N50 Silver Lake Dover Capitol Green 2
Edgehill/Dover
N51 Silver Lake Dover
Heights
N114 Silver Lake none Capitol Park
N173 Silver Lake none Quails Nest
N4 Silver Lake Dover Maple Dale Retreat
N202 Silver Lake None Meadow Ridge
N3 Silver Lake Dover The Meadows
N60 Silver Lake none Carlisle Village
Elm Terrace & State
N47 Silver Lake Dover
St
N48 Silver Lake Dover Kent Ave
Division St &
N39 Silver Lake Dover
Governors
N63 Silver Lake None Foxhall
H501 Silver Lake Dover US Gas
Cheswold Recycle
H504 Silver Lake none
Center
H502 Silver Lake Dover Wawa
DE Tech & Comm
R14a Silver Lake Dover College, Terry
Campus
R107a Silver Lake Dover Del Taco
R4a Silver Lake Dover Kmart
R10a Silver Lake Dover Golden Corral
Low Proctor & Gamble
R20a Silver Lake Dover
North Building
R27a Silver Lake Dover Dover Mart
DE Tech & Comm
R14b Silver Lake Dover College, Terry
Campus
Proctor & Gamble
R21a Silver Lake Dover
South Building
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R19d Silver Lake Dover Dover High School
R200a Silver Lake none A & H Uniform
R501b Silver Lake Dover US Gas
N2 Silver Lake Dover Maple Glen Dr
N21 Silver Lake none Zurkow Lots
Rt 8 & Sharon Hill
N69 Silver Lake None
Rd
H301 Silver Lake Dover Gas Station/U-Haul
H303 Silver Lake Dover Car Zone
Poors Energy
H503 Silver Lake none
Service
H507 Silver Lake Dover Jiffy Lube
Edgehill Shopping
H508 Silver Lake Dover
Center
H500 Silver Lake Dover Auto Zone
H509 Silver Lake Dover Self Wash/Wax
*Property owners have not been contacted as part of the
preparation of this report.
Sub-Watershed Key
St. Jones
Tidbury Creek
Isaac Branch
Silver Lake
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Table 6. Watershed wide WMWQ scores ranked highest to lowest (Duffield 2008).
Screening Categories for SITE IDENTIFICATION NUMBERS
WMWQ Technologies
12/
18 16 5 8 27 1 10 7 14 26 23 3 6 15 21 22 25 17 19 2 20 9 24 11 4
13
CREATION/RESTORATIO
N OF UPLAND BUFFERS 38 40 41 47 40 38 36 46 37 37 37 40 38 29 34 27 28 33 37 27 34 26 37 28 25 32
WETLAND/FLOODPLAIN
CREATION AND/OR
RESTORATION 56 57 54 49 54 39 49 44 49 42 37 34 38 38 38 38 38 32 36 36 25 36 28 38 27 24
INFILTRATION 44 41 40 40 40 42 43 36 39 40 43 40 36 42 39 40 40 39 39 37 35 37 27 29 36 31
STREAM CHANNEL
IMPROVEMENTS 39 37 30 38 35 33 32 36 36 32 31 33 34 37 35 31 31 31 30 32 39 32 29 22 32 27
PRESERVATION OF
STREAMS, WETLANDS &
BUFFERS 32 25 26 21 23 32 21 20 24 23 24 30 26 22 23 32 26 26 9 25 19 23 28 25 20 19
FLOOD CONTROL 18 17 19 17 13 19 20 13 5 14 14 6 9 12 11 6 10 12 16 10 13 10 7 13 12 13
22 21 21 21 20 20 20 19 19 18 18 18 18 18 18 17 17 17 16 16 16 16 15 15 15
TOTAL SCORE
7 7 0 2 5 3 1 5 0 8 6 3 1 0 0 4 3 3 7 7 5 4 6 5 2 146
* Property owners have not been contacted as part of the preparation for this report. Red numbers are highest technology scores.
Sub-Watershed Key
St. Jones
Tidbury Creek
Isaac Branch
Silver Lake
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Figure 4. Initial recommendation sites for the Silver Lake sub-watershed (Duffield 2008).
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SUB-WATERSHED MANAGEMENT OPPORTUNITIES
INTRODUCTION
With a strategy in place, partners and other organizations have a more focused approach to
improving the quality of the St. Jones Watershed. The Silver Lake sub-watershed strategy
may not fulfill the priorities of every organization and may be limiting for those with
specific objectives. However, the strategy provides direction for future management
opportunities. As part of the “St. Jones Watershed Implementation Plan” (Plan) by Duffield ,
priority lists were developed to target pollution control opportunities within the Silver Lake
sub-watershed. These lists use different strategies such as upland sites, Watershed
Management for Water Quality (WMWQ) technologies, neighborhoods, hotspots, and
preservation to identify target projects. The lists developed by the Plan are a place to begin
efforts. It is not meant to be implemented strictly in chronological order, but instead used
as a guide for watershed improvement activities that ultimately depend on partner
cooperation and funding availability.
The lists below provide an overview of the current efforts occurring in the Silver Lake sub-
watershed to improve water quality. These projects, identified either before or recently
after the Plan was written, were chosen based on landowner and partner cooperation and
willingness to collaborate on the proposed improvement projects. The site name and
identification code are listed next to those sites identified in the Plan’s list of potential
upland sites. The Plan provides useful cost estimates of Best Management Practices (BMP)
identified for individual upland projects that may help with decisions with budgets.
Another useful tool is the expected pollutant removal by each BMP and the associated costs,
therefore providing the cost effectiveness of each project. Common storm water BMP and
their associated nutrient removal rate are presented in Table 7.
WMWQ technologies are also listed in the Plan and show a great deal of potential. The
WMWQ technologies are a reflection of the specific types of pollution control measures
identified by the St Jones Tributary Action Team (TAT) in the Pollution Control Strategy
(PCS Addendum 1) to improve water quality within the watershed. These projects are
typically larger scale and require more land area, space, and most importantly, participation
from private landowners. The benefits, however, are just as successful as upland/urban
retrofits as they occur mostly in the headwaters of the Watershed and sub-watersheds.
Planners and land managers should reference this strategy and the Plan for guidance on
future project planning.
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Table 7. BMP Percent Reduction of Nutrients from Urban Runoff
BMP Total Nitrogen (%) Total Phosphorous
(%)
Stormwater Wet Ponds 40 50
Sand Filter 47 41
Stormwater Dry Ponds 15 25
Stormwater Wetlands 30 49
Infiltration Practices 65 70
Water Quality Swales 25 34
Rain Garden 43 81
SILVER LAKE SUB-WATERSHED PROJECTS
CURRENT PROJECTS
1. Dover High School. Located at Walker Road and Patrick Lynn Drive in Dover, DE, the
high school campus would benefit from better stormwater infiltration practices. URS
Corp. has submitted a proposal for design and conceptual work for the site. Several
ideas were proposed, and after site visits, design consultations, and meetings with
school personnel, the following projects were designated as the best options:
construction of a rain garden to collect stormwater runoff from the parking lot
surface;
restoring function and prevent erosion to the discharge area in the unnamed
channel;
increasing water volume entering the wetland/storage area in the existing
stormwater wetland to improve nutrient removal.
The rain garden alone will prevent 5 pounds of nitrogen, 0.5 pound each of phosphorus
and zinc, and 275 lbs of sediment per year from entering Silver Lake. The pollutant load
reduction for the stormwater wetland retrofit is yet to be determined, but should be
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comparable to the previous reductions, if not more. Reference in Duffield: Site Name:
R19 – Dover High School.
2. Delaware Agricultural Museum and Village. Located off of Rt. 13 southbound in Dover,
DE, the Agricultural Museum and Village (Museum) property was identified in the
Duffield report for a conversion of a dry pond to a bioswale. The dry pond conversion,
in addition to other enhancements, has recently been completed with funds primarily
from the Clean Water Advisory Council’s Community grant. Plans to convert it to a
bioswale and re-grade adjacent land to direct water flow away from Museum buildings
and towards the bioswale have recently been completed. Two rain gardens, on either
side of the Museum entrance, collect almost half of the stormwater runoff from the roof
where it previously was discharged onto mowed grass. Additionally, a 10-foot buffer
encircling three sides of Mill pond was planted to discourage Canada geese from nesting
and traversing between the pond and land. Six floating wetlands, a new technique used
to improve the water quality, were launched in Mill pond. Water samples were
collected to monitor the effect floating wetlands had on phosphorus, nitrogen, and
bacteria removal. Fencing was installed along the Silver Lake shoreline on Museum
property to reduce the number of geese entering the property via Silver Lake. The
bioswale is estimated to remove 1 pound each of phosphorus and zinc, 7.5 pounds of
nitrogen, and 500 pounds of sediment per year. Each rain garden is estimated to reduce
phosphorus and nitrogen by 45%, zinc by 80% and sediment by 60%. The removal of
nutrients and bacteria from the Mill pond due to the floating wetlands and vegetated
buffer are still being monitored through water sample analyses, but are expected to
reduce bacteria significantly. Reference in Duffield: Site Name: R30 – DE Agricultural
Museum.
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3. Delaware Technical and Community College. Located at Scarborough Road and Route
13 in Dover, DE. The Technical and Community College’s campus offers an opportunity
to work with students and officials to create a stormwater management and
sustainability plan that will address the College’s future needs of expansion while
maintaining and enhancing stormwater infiltration and bioretention practices. Cost
estimates are currently being determined for potential projects including: several rain
gardens, converting a tax ditch to a bioswale, step pool conversion, and re-grading areas
to collect more water for treatment before entering the storm drain system untreated.
All project combined would remove approximately 4.25 pounds of phosphorus, 37
pounds of nitrogen, 3.6 pounds of zinc, and 3,502 pounds of sediment per year from
entering Silver Lake. Reference in Duffield: Site Name: R14 - DE Technical &
Community College, Terry Campus.
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4. Fairview Elementary School. Located at the intersection of Walker Rd and Pear St in
Dover, DE. The principal at Fairview Elementary school has agreed to disconnect
several downspouts to construct a large rain garden near the building where students
and faculty pass by regularly. Education on rain gardens and stormwater runoff will be
incorporated into lesson plans and will continue even after construction ends. In
addition, the rain gardens will remove 0.5 pound of phosphorus, 3.75 pounds of
nitrogen, 0.5 pound of zinc, and 250 pounds of sediment per year from stormwater
runoff. Reference in Duffield: Site Name: R29 – Fairview Elementary.
5. Silver Lake Park. Located adjacent and south of the Silver Lake dam with parking off of
Washington Street and Lewis Mill Drive in Dover, DE. As part of a cooperative effort
amongst DNREC’s Watershed Assessment Section, 319 Nonpoint Source Program,
Division of Parks and Recreation, DELDOT’s Environmental Program, City of Dover’s
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Silver Lake Commission, and Polytech High School the Silver Lake Park Revitalization
Plan was developed to improve water quality in the St. Jones River while improving the
aesthetic value of the river to Dover residents and park visitors. Comments from Dover
residents and members of the public were incorporated as much as possible to ensure
the park would still serve the needs of its primary stakeholders. Several key projects
were identified and broken down into four implementation phases (Figure 5). Each
phase included a plan to establish riparian buffer along the river in a tiered system that
incorporates grasses and trees and can reduce sediments up to 96%, nitrogen up to
95% and phosphorus up to 79% (www.nrcs.usda.gov/NRCSProg.html). Phase 1 of the
Revitalization Plan is almost complete with the northern portion’s riparian buffer
complete, but still lacking park benches and educational and interpretive signage. The
southern portion of Phase 1 is currently on hold until other phases are closer to
completion. DNREC hired Biohabitats Inc. to develop the design of Phase 2, including
the discharge received by Washington Street in the drainage ditch adjacent to the park
that empties to the St. Jones River. After extensive surveying and planning, Biohabitats
created several options to choose from for the stabilization and restoration of the St.
Jones River near the dam. Shortly after, a public meeting was held in conjunction with
DNREC, City of Dover, Silver Lake Commission and Biohabitats to determine the final
design based on public input received during the meeting. The figure below is a detailed
sketch of the proposed design of the work to be done along the east side of the River and
park. The Mill Race, or wetland slough as identified in the sketch below, was added
later to address the excessively wet “island” area (Figure 6). During field review, the
required permitting agencies determined the design would need to be revised slightly to
meet state and federal standards. Permits for this project were received at the end of
February 2011 and bidding for construction is currently underway. Design plans are
currently being completed for Phase 3 in conjunction with partners from the City of
Dover and Kent County Parks & Recreation and will be planted in the Fall 2011.
Portions of Phase 4 have been completed with help from the City of Dover, Kent County
Parks & Recreation, Elizabeth Murphey School, and Central Middle School (see “Partner
Projects” listed below for more information). Other projects are in development and
will address storm water runoff and connect the riparian corridor (see DNREC Richards
& Robinson’s property, Figure 7).
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Figure 5. Silver Lake Park Revitalization Plan with Phases 1-4 identified.
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Figure 6. Biohabitats rendition of the proposed restoration and stabilization along the
St. Jones River.
6. Washington Street. Storm water runoff exiting from Washington Street in Dover, DE,
the entrance road to the beach side of Silver Lake Park, is currently discharging
untreated directly into the St. Jones River. Plans for a regenerative step pool
conveyance system are currently under way and should be completed in conjunction
with Phase 2 of the Silver Lake Park Revitalization Plan. The step pool system is
projected to reduce Nitrogen and Phosphorus by 45% and sediment by 60% from the
stormwater that currently drains from the approximately 17 acres of adjacent land.
Using a common loading rate for the Dover area, reductions using this technology for
the said acreage of land are estimated to remove 121.7 pounds of Nitrogen, 16.5 pounds
of Phosphorus, and 8500 pounds of sediment per year.
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7. DNREC Richards & Robinson’s property. Located in downtown Dover, DE at 89 Kings
Highway. Storm water runoff from this parcel is currently draining to Mirror Lake
untreated. As part of DNREC’s environmental improvement plan, storm water runoff
will be directed through a series of storm water BMP’s while an increase in riparian
buffer width will also help remove pollutants from entering Mirror Lake. This plan will
also attempt to address the sediment bar and associated contaminants found in Mirror
Lake at low tide. Residents and scientists will work together to develop a solution. See
“Mirror Lake: Analysis of Chemical Contaminants in Sediments,” 2011 and the DNREC
“Environmental Improvement Plans for Selected DNREC Office Sites,” 2011 for more
detailed information.
Figure 7. DNREC Richardson & Robbins property and the proposed environmental improvements
adjacent to the St. Jones River
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PARTNER PROJECTS
8. Elizabeth Murphey School. Located on the north side of East Division Street and west of
the St. Jones River in Dover, DE. This area is located directly across from the riparian
buffer planted in Phase 1 of the Silver Lake Park Revitalization Plan. The low-lying land
adjacent to the river was being mowed all the way to the edge of the river and
experienced frequent ponding or flooding during heavy rainfall. The shoreline was
severely eroded from human and animal traffic as well as water velocity in the river. In
the spring and fall of 2010, partners from Kent County Parks and Recreation, City of
Dover, and DNREC established a tiered riparian buffer and approximately 120 linear
feet of “living shoreline” consisting of biocoir logs and vegetating the backfilled soil
medium.
9. Central Middle School. Located on the north side of East Division Street and the
Elizabeth Murphey School and west of the St. Jones River in Dover, DE. The area
surrounding part of the St. Jones River that flows from the dam on the south side of
Silver Lake (Park) to the intersection of Loockerman Street at Mirror Lake is a widely
used area. Currently, the grassed area between the school and the River is mowed
almost directly to the bank. The partial wooded area of the project has extensive areas
of invasive species (Japanese honeysuckle, English ivy, Phragmites, Virginai creeper,
Trumpet Crepper, Porcelain berry, Autumn Olive, tree of Heaven, Multiflora rose, and
Privet). The invasive plants will be removed and sprayed with the help Delaware
Division of Parks and Recreation before the buffer is planted with native species. In
addition, an outdoor classroom will be created using recycled tire (semi-permeable)
flooring area creating a seating/classroom area. Students, in accordance with 7th grade
science curriculum, will test water quality annually in order to determine the health of
our local Silver Lake/St. Jones watershed. Additionally, students will use digital
photography to meet further Science standards. A tiered riparian buffer system, which
incorporates grasses and trees, can reduce sediments up to 96%, nitrogen up to 95%
and phosphorus up to 79%.
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10. Natural Resource Conservation Service (NRCS) building. Located off of College Park
Drive in Dover, DE. In 2010, partners from the Partnership for the Delaware Estuary,
NRCS, and Environmental Concern designed and installed a rain garden to collect runoff
from the adjacent parking lot and roof. Using help from students of North Dover
Elementary school, the rain garden was planted with 600 native plants to treat storm
water runoff before it enters the river system untreated.
11. Silver Lake Dam stabilization. The City of Dover’s Emergency Management Division
complied with the insurance agency overseeing the Silver Lake dam by making
necessary improvements. These improvements included vegetating either side of the
dam’s northern portion and fencing it off to prevent damage from waterfowl of park
visitors. Large rip rap was also installed to reduce the any additional erosion along the
banks due to wave action, foot traffic, and wildlife use. As a result, these improvements
will discourage foot traffic to vulnerable areas and improve the safety and
environmental integrity of the structure and surrounding area.
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ii. Education and Outreach
i) Rain Gardens for the Bays. EPA Region 3 initiative to reduce storm water runoff
entering “our bays” including the Delaware Bay, Delaware’s Inland Bays, and Maryland’s
Coastal Bays by installing rain gardens in the Bays’ watersheds. To date, three rain
gardens exist in the St. Jones Watershed, including 2 at the Delaware Agricultural
Museum, 1 at the Natural Resource Conservation Services (NRCS) office off of College
Park Dr. and 1 at Fairview Elementary School with assistance from the Partnership for
the Delaware Estuary.
ii) Fertilizer Campaign. Marketed as “Livable Lawns,” this campaign targets landscaping
companies and homeowners that apply fertilizer to lawns. The campaign aims to
educate homeowners and landscape professionals about the consequences of excessive
fertilizer use and fertilizer alternatives while ultimately reducing the amount of excess
nutrients reaching Delaware waterways.
FUTURE OUTLOOK OF THE SILVER LAKE SUB-WATERSHED
The St. Jones Tributary Action Team (TAT) developed recommendations to reduce non-point
source nutrient and bacteria loads to the St. Jones Watershed in order to meet the 2006 Total
Maximum Daily Load (TMDL) as established by the Environmental Protection Agency (EPA).
Through extensive education and discussion, the St. Jones TAT developed recommendations for
open space, stormwater, wastewater, agriculture, and education. These recommendations were
submitted in the form of a Pollution Control Strategy (PCS) to then-Secretary of DNREC, John
Hughes. The St. Jones PCS is currently being finalized and will be submitted to EPA shortly
thereafter. The document is an excellent resource for a citizen perspective of important issues
related to improving the water quality of the St. Jones Watershed.
Within the storm water section of the St. Jones PCS, the TAT recommends implementing a storm
water utility to generate a stable source of funding for storm water management throughout the
watershed. Governor Minner’s Task Force on Surface Water Management quantified the statewide
financial need for stormwater management. “The Finance Subcommittee identified stormwater
capital requirements of $207.3 million over the next five years and projected annual maintenance
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requirements of $13.73 million” (URS Corporation, 2009). The Task Force thus recommended that a
stormwater utility operating at the county or local level should be formed as a funding vehicle for
the purpose of providing a simplified and comprehensive approach to drainage and flooding
problems. A stormwater utility is an approach that can generate a stable source of funding for
stormwater management within the region. The funds are made available by collecting user fees.
Stormwater utility fees are generally set by the amount of impervious cover on each resident’s
property. The higher the impervious cover the higher the fee. GIS mapping will be utilized to
measure impervious surface generated by residential and commercial development, and the utility
fee will be charged based on the property’s Equivalent Residential Unit (ERU). In fall 2011,
members of the City of Dover’s Council will be invited to participate in a tour of existing stormwater
structures throughout the City and entire Watershed to examine the costs associated with
maintaining quality facilities.
There are many benefits of a stormwater utility. According to DNREC, Division of Watershed
Stewardship, Watershed Assessment Section, a stormwater utility can generate up to $10 per capita
per $1/month/ERU. It is estimated that approximately one-eighth to one-sixth of the annual
revenue from a $1/month/ERU stormwater utility results in approximately $30,000--$40,000 for
cities and approximately $180,000--$250,000 for counties (Christina Tributary Action Team and
Water Resources Agency, 2007). The revenue generated from the utility can be used to fund a
variety of stormwater management and water quality programs. This tool can be used in the St.
Jones Watershed to contribute to the reduction of nutrients and bacteria reaching the rivers and
streams by implementing best management practices with the funds generated from the
stormwater utility.
Efficient implementation of best management practices and water quality improvement projects
depend largely on staff resources. It is suggested that the stormwater utility be used to fund a staff
position/Watershed Coordinator dedicated to managing and implementing the projects throughout
the St. Jones Watershed. New projects will require researching appropriate funding and attention
to detail during design and engineering phases. Stable funding for a Watershed Coordinator
becomes more important when completing multi-phased or long-term projects. Also, creating an
established position will allow the Watershed Coordinator to create and maintain local contacts,
thereby generating support and resources for future projects.
The Sediment and Stormwater regulations serve as an enabling structure for the local ordinances
needed in order to set up the utility. For example, the City of Wilmington has established a
stormwater utility for residential and commercial customers in the municipality where all
properties pay a stormwater charge based on their impervious cover.
Before funding even becomes available, potential projects should already be identified in a priority
list. Once funding does become available the process will move much quicker and smoother if all
research and cost-estimates are completed ahead of time. During the course of current project
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implementation by the St. Jones Watershed Coordinator and partners, a list of potential projects
have surfaced through both the Plan and amicable partnerships developed with landowners,
businesses, and partners. The following are projects currently being researched for further
potential as a stormwater improvement project:
Site Location Description of project Landscape Duffield
position priority
Super Fresh Dover, Silver Convert existing dry Headwaters High
Lake Sub- pond to large, passive
watershed bioretention.
Modern Dover, Silver Convert dry pond to Headwaters Medium
Maturity Center Lake Sub- bioretention
watershed
Behind Dover Dover, Silver Regenerative Adjacent to Unlisted *
Pools & Ag Lake Sub- stormwater conveyance Lake
Museum watershed system
Winding Creek Dover, Silver Potential for Headwaters; Duffield
DE, LLC Lake Sub- wetland/floodplain confluence of WMWQ
watershed creation and/or Maidstone & Project #
restoration, stormwater Penrose 12/13
infiltration, stream Branches
channel improvements,
preservation, and flood
control.
Private Dover, Silver Potential for Headwaters; Duffield
Landowner Lake Sub- wetland/floodplain adjacent to WMWQ
watershed creation and/or Cahoon Project #
restoration, stormwater Branch 18
infiltration, stream
channel improvements,
and flood control.
* Untreated stormwater discharge into Silver Lake behind Delaware Agricultural Museum
& Village and Dover Pools. Identified while completing BMPs on the Ag Museum property.
Developed a positive relationship with staff at the Ag Museum.
Outside funding sources may help supplement or extend the life of funds generated by the
stormwater utility. Partnering with other organizations (state, county, and municipal agencies,
non-profits, etc.) help leverage funds and promote productive and successful partnerships.
Funding sources used in the past include: Delaware’s Clean Water Advisory Council’s Community
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Water Quality Improvement Grant, 319 Non-Point Source grant, Delaware Land and Water
Conservation Trust Fund Trail Grant, and Community Environmental Project Fund (penalty funds).
New funding sources may arise and should be explored. Also, some funding sources are better
suited for certain projects than others. It is important to apply for the grant that most
appropriately fits the objectives and goals of each project.
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WORKS CITED
Christina Tributary Action Team and Water Resources Agency. (2007). The Christina Basin
Pollution Control Strategy. Dover: DNREC.
Division of Soil and Water Conservation. (n.d.). Improving Silver Lake: Forebay Project.
Dover, DE, USA: Delaware Department of Natural Resources and Environmental
Control.
DNREC. (April 2010). Combined Watershed Assessment Report (305(b)) and Determination
for the Clean Water Act Section 303(d) List of Waters Needing TMDLs. Dover:
Delaware Department of Natural Resources and Environmental Control.
DNREC, City of Dover, and Advisory Committee. (1996). Options for Protection and
Improvement of Silver Lake. Dover: DNREC.
Dover, C. o. (1990, August 27). Proposed Resolution-Silver Lake Commission. Dover, DE,
USA.
Duffield Associates, Inc. (February 2009). St. Jones River Watershed Implementation Plan.
Wilmington: Duffield Associates, Inc.
Duffield Associates, Inc. (October 2008). St. Jones River Watershed Pollution Control
Opportunities: Technical Memorandum. Wilmington: Duffield Associates.
Edgell, D. (2011, January). Planner, former Silver Lake Commission President. (L. Allison,
Interviewer)
F.X. Browne. (1988). Phase 1: Diagnostic-Feasability study of Silver Lake. Dover: F.X. Browne.
Greene, R. (2011, January). Engineer. (L. Allison, Interviewer)
Rogerson, A. B., Jacobs, A. D., & Howard, A. M. (2010). Wetland condition of the St. Jones River
Watershed. Dover: Delaware Department of Natural Resources and Environmental
Control.
Shaffer, E. (1989). Technical Background Report. Dover: Delaware Department of Natural
Resources and Environmental Control.
Tyler, R. (2011, January). Environmental Scientist, DNREC. (L. Allison, Interviewer)
URS Corporation. (2009). Kent County Level of Service Analysis of Surface Water Management
Needs. URS Corporation.
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Silver Lake Commission Members
Name E-mail Phone # Ok to share with
SLC members
Anthony Morris
Cary Smith
Kathy Doyle
John DeMarie
Michael Lewis
Carolyn Courtney
One Vacant position exists
Page 174
2026 thru 2026
Capital Improvement Plan
Dover, DE
Project# PR2600
Project Name Silver Lake Master Plan
Total Project Cost $75,000 Department Parks and Recreation
Type Improvement Category General
Priority n/a Status Active
Time-Line: FY26 Account Number: 101-13-15-12-D00-54031
Expenditures 2026 Total
Construction/Maintenance 75,000 75,000
Total 75,000 75,000
Funding Sources 2026
75,000
----- Total
75,000
General Fund
Total
--------------75,000
75,000
--
FY2 C pital Improvements Plan: Silver Lake Park Master Plan
To promote a more aesthetic, environmentally friendly, welcoming and safe environment at
our Silver Lake Park. The Master Plan would include landscape design plan to improve
access to existing facilities and parking therein.
Master Plan will address the current paved trail offering relief to those who actively use the
park for running/jogging, biking, etc.
The Master Plan for Silver Lake Park will offer the City the tools needed to appropriately
plan Silver Lake Park and its facilities. Assessment & Design must include:
• Fitness Stations along Paved Trail
• Woodlands Assessment
• A plan to preserve the old African American cemetery
• Consideration of current and future parks facilities such as:
• The Lake, Beach Area, Indoor Bathrooms
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IMPORTANT THINGS TO KNOW!
Silver Lake adds to Dover’s historical and natural charm. As property owners near this local treasure, knowing and
understanding the rules that govern the lake will ensure everyone’s safety and the lake’s continued protection!
WHAT CAN I DO TO MY PROPERTY/DOCK WHILE THE DAM VALVE IS OPEN?
IF YOU WANT TO REPAIR OR CHANGE YOUR DOCK AND/OR SHORELINE STABILIZATION:
First, if you want to make any repairs or changes to any docks, shoreline stabilization structures, or any
other structures that are usually below or near the regular water level line, then you will need to obtain a
permit from the Delaware Department of Natural Resources and Environmental Control’s Wetlands and
Waterways Section before any work is initiated. To contact DNREC’s Wetlands and Waterways Section
please call 302-739-9943 or visit:
https://dnrec.delaware.gov/water/wetlands/
IF YOU WANT TO REMOVE DEAD OR FALLEN TREES:
You will also want to speak with someone from DNREC’s Wetlands and Waterways
Section if you would like to remove any fallen trees or tree limbs that are on or near
the shoreline. To contact DNREC’s Wetlands and Waterways Section please call
302-739-9943 or visit
https://dnrec.delaware.gov/water/wetlands/
IF YOU WANT TO REMOVE WEEDS OR OTHER GRASSES:
Make sure what you are removing is actually a weed!! Some native plants and grasses may look “weedy”
but are actually beneficial to the lake and local wildlife. Having native grasses and plants on your property
will actually help you keep the REAL weeds off your property.
IF YOU WANT TO REMOVE LITTER AND TRASH:
Please feel free to remove any litter, trash, garbage, or any other refuse that has no business being in a lake!
Examples are: glass bottles, anything made of plastic (such as bags and bottles), paper litter, and old tires.
Just make sure to properly dispose or recycle the refuse.
WHY DO I NEED A PERMIT TO REPAIR OR REMOVE SOMETHING THAT IS ON MY PROPERTY?
The State of Delaware protects certain areas that are critical natural resources and habitats, such as rivers, lakes, and
wetlands; Silver Lake is one of those protected places. The Lake is a place where many wildlife species (such as
birds, fish, reptiles, and amphibians) can nest and feed. Therefore, any changes in Silver Lake can cause
disturbances to wildlife habitats and water quality. For example, that old rotting tree that fell over 5 years ago may
be home to fish and provide your property with erosion protection!
The DNREC Wetlands and Waterways Section authorizes activities in Delaware’s tidal wetlands, bays, rivers,
streams, lakes, ponds and other waterways. Types of activities that could require permits include constructing,
repairing, or changing docks and/or placing objects in or near the water to stabilize the shoreline. Please contact
the Wetlands and Waterways Section before you perform any modifications to your property.
STILL HAVE QUESTIONS?
Contact Andy Howard, Division of Watershed Stewardship at 302-739-9939 or by email at
Andrew.Howard@delaware.gov.
Page 178
July 3, 2025
Dear Silver Lake Licensed Boater:
Beginning Monday, October 6, 2025, through Friday, October 17, 2025, the City of Dover plans to open
the valve on the Silver Lake Dam. As a result of the valve opening, the water level of Silver Lake may
visibly be lower. The City of Dover periodically opens the valve in an effort to allow surrounding property
owners the opportunity to remove litter from the lake bank and make any approved necessary repairs along
the shoreline. The last time the valve was opened for this reason was in October of 2024.
During this time period and until the water level of the lake returns to its normal level, boaters should use
extreme caution on the lake, and all boating on the lake will be at the risk of each boater. Also, if your boat is
docked on Silver Lake, then you may want to make other arrangements for storage.
The City of Dover is not responsible for any damage to boats using the lake or boats docked on Silver Lake
during this time period.
The valve will only be open until October 17, 2025, to ensure that the fish population of the lake will not be
disturbed. During this time water levels will be closely monitored.
We apologize for any inconvenience that this may_cause, but the end result will be a cleaner and safer lake to
enjoy.
If you should need more information or have questions or concerns, please contact Carolyn Courtney of the
City of Dover Parks & Recreation Department by calling (302) 736-7050 or email at ccourtney@dover.de.us.
Cordially,
Roger Ridgeway,
Director, City of Dover
Parks & Recreation Department
Cc: Silver Lake Commission
Parks & Recreation Community Enhancement Committee
Dave Hugg, City Manager
Sharon Duca, Asst City Manager
Thomas A. Johnson, Chief of Police
Mark Nowak, Public Works Director
Dawn Melson-Wilson, Principal Planner
Andy Howard, Watershed Div. DNREC
P.O. Box 475, Dover DE 19903-0475
Communitu Excellence Through Quality Service
Page 179
The St. Jones Watershed: #18 on map
DNREC’s testing shows that this watershed needs to reduce its nonpoint phosphorous and
nitrogen loads and phosphorous loads by 40% and its nonpoint bacterial loads by 90%.
(Nonpoint means cannot pinpoint precise location of causes.)