New Castle County
The project addressed high nutrient concentrations causing advanced eutrophication in Silver Lake, Noxontown Pond, Wiggins Mill Pond, and Shallcross Lake. The principal water uses of these water bodies are primary and secondary contact recreation, maintenance and propagation of fish and aquatic life, industrial and agricultural water supply, drainage, navigation (tidal portion), and passage of anadromous fish. Silver Lake has been closed to primary contact recreation due to bacterial contamination. Noxontown Pond has been impaired by excessive algae growth, inhibiting its use for boating. Algae in Silver Lake has caused a decline in desirable fish species populations. Fish kills have occurred in several of the lakes.
The objective of the Appoquinimink River project was to install best management practices (BMPs) in order to reduce erosion and nutrient transport, decrease nutrient applications to cropland, and properly manage animal waste. The BMP emphasized in the project was the conversion of row crop cultivation to no-till. Pesticide and fertilizer management were also promoted through the Rural Clean Water Program (RCWP) project.
The critical area (13,000 acres) was defined based on soil erosion rates, the presence of gully erosion, concentration of animal wastes 1,500 feet or less from a stream, and the need for better farm management with respect to application of fertilizer, pesticides, and animal wastes. The implementation goal was to treat 9,750 acres of the critical area.
A water quality monitoring program included storm event sampling conducted seasonally in Noxontown Pond, Silver Lake, and Shallcross Lake. However, baseline data for Silver Lake and Noxontown Pond are lacking. Ground water monitoring was added in 1984 to determine to what extent, if any, the installation of BMPs was affecting ground water quality.
Producer participation was excellent, with 60% of the farmers, representing 87% of the critical area, participating in the project. Of the 130 farms in the watershed, 76 were under contract through the RCWP project. Over 11,000 acres in the critical area were treated to reduce nonpoint source (NPS) pollution from agricultural activities.
An unexpected reaction to the project was that farmers outside the project area were upset that they were ineligible to participate in the RCWP project.
Through the RCWP project, no-till acreage was increased from about 50% of the cropland to 90% in the project area. In addition, farmers reduced pesticide use; planted cover crops to reduce winter runoff; and installed grassed waterways, filter strips, and other measures.
Significant reductions in soil erosion and improved fertilizer and pesticide management practices have lowered the level of suspended solids in the river by 60%. In one of the ponds, monitoring showed that sediment levels have declined by 90% and total phosphorus has decreased by 65%.
The Appoquinimink River project combined excellent inter-agency cooperation and an effective information and education (I&E) program with a farm community having a strong interest in the RCWP project. The water quality monitoring program was handicapped by lack of pre-project baseline data; however, a significant reduction in suspended solids and phosphorus in the lakes was measured.
The benefits of the project have extended into other parts of New Castle County; most farmers in the county have voluntarily adopted no-till as their primary tillage practice. However, the use of no-till in corn production has significantly dropped due to slug damage and lack of a safe and effective pesticide control.
Figure 4.2 Appoquinimink River (Delaware) RCWP project map, DE-1.
Original land treatment goals (100% of the critical area) were ambitious, though based on previous high project participation rates in an earlier demonstration project. The goals were later revised to more realistic levels (75% of the critical area).
A disproportionate percentage of project funds was earmarked for cost sharing land treatment, while insufficient funds were available for I&E and water quality monitoring programs.
Early involvement of producers in identifying the water quality problem and its source as well as deciding on and planning the project is key to a successful outcome.
Administration of the project by the Agricultural Stabilization and Conservation Service (ASCS) was effective because: 1) members of the ASC County Committee that worked with the Local Coordinating Committee (LCC) were farmers elected by their peers, bringing a strong community base of support; 2) ASCS had experience administering the Agricultural Conservation Program; and 3) ASCS was able to undertake the project without hiring new staff.
Appropriate reporting is necessary to provide feedback to project staff, funding agencies, and the public and to motivate agency staff to meet project goals. However, water quality project paper work should be streamlined to avoid excess reporting and documentation. Reporting requirements for the entire project period should be clearly outlined at the beginning of the program (Carty et al., 1991).
It may be helpful for SCC members to attend the meetings of other project SCCs on occasion to help facilitate sharing of resources and solutions among projects nationwide.
Local and state agencies should receive adequate advance notice of water quality program eligibility to enhance sound planning and selection of projects with a good possibility of success.
Plans were completed for 76 farms resulting in 76 contracts covering 13,000 critical acres.
The project has shown that voluntary programs for BMP implementation have resulted in conservation tillage becoming an acceptable practice for many farmers.
The project has demonstrated that farmers are willing to make adjustments in their practices to help improve water quality.
Although producers have experienced some problems with slugs in corn crops under conservation tillage due to a lack of an effective and safe pesticide, conservation tillage is still the BMP of choice for sediment control and nutrient reduction.
Projects that rely on management BMPs need specialists for effective implementation (e.g., pest management, weed control, fertilizer use). Technology transfer of management BMPs from farm to farm is critical for overall project success.
Producers installing conservation measures under the Section 208 program provided a favorable lead-in for the RCWP.
Most farmers report using soil tests to help plan for nutrient crop needs. In addition, most farmers side-band rather than broadcast fertilizer at planting and apply most nitrogen after crops are growing (split application), when crop uptake is greatest.
The use of scouting in association with pesticide management has resulted in a reduction of the amount of pesticides applied in the project area.
An innovation on a BMP developed in this project is the use of rock pads during construction of waterways to keep gullies from moving up a waterway.
Additional technical help with management practices (fertilizer, pesticide management, tillage) is very helpful in the field (Carty et al., 1991).
The economics of growing crops and the costs of implementing practices to improve water quality need to be constantly assessed in order to continue the process of identify and implementing practices that both reduce agricultural NPS pollution and are affordable and acceptable to producers.
Use of annual aerial photographs could assist in tracking of land use and BMP installation.
Voluntary programs for BMP implementation have resulted in conservation tillage becoming an accepted practice for many farmers. Since BMPs were installed, however, orthophosphate concentrations (as a proportion of total phosphorus concentrations) have increased in the watershed and BMPs have failed to decrease downstream nitrogen loading.
The project lacked strong pre-project baseline data and the monitoring program would have been more useful if extended to 10 to 15 years.
Delivery of suspended solids and nutrients from agricultural lands to surface streams has declined 90% from pre-RCWP levels. The delivery of total phosphorus to the stream has shown a similar decline. Both filtered and unfiltered total phosphorus have been reduced more than 60% from pre-RCWP levels. Orthophosphorus concentrations, however, increased somewhat over the first years of the study before declining to about 65% of pre-RCWP levels. Nitrogen loads to the stream have declined less than 25% from pre-project levels.
Reduced suspended solids concentrations, and hence increased water clarity, have resulted in significant increases in algal growth in the downstream ponds. Nutrient concentrations have not varied significantly over the last four years of the project, indicating that pond sediments contribute sizable quantities of nutrients to pond waters. Water quality in the ponds can still be described as enriched.
Funding should be made available for adequate pre-project monitoring and for an extended during and post-project period in order to maximize chances of documenting the effects of land treatment implemented.
Cover crops reduced suspended solids and phosphorus entering project area lakes and ponds.
Pre-project baseline data are essential to document land treatment - water quality linkage.
Geologic Factors: The watershed is underlain by deep sediments covering the bedrock. The surface formation consists largely of medium to coarse sands and gravels. This formation is an important water supply presently used as a potable water source for public and private supplies. The predominant soil type is deep, well-drained and medium to coarse textured. Slopes are nearly level in the uplands and steep near the stream channels.
Use % of Project Area % of Critical Area Cropland 64 62 Pasture/range 4 NA Woodland 13 NA Urban/roads 5 NA Other Wetlands/Open water 14 NA
Operation # Farms Total # Total Animal Animals Units Dairy 7 945 1,323 Beef 2 293 293 Hogs 1 NA NA Poultry 1 70,000 2,310
SOURCES Federal State Farmer Other
ACTIVITY SUM Cost Share 873,196 0 328,366 0 1,201,562 Info. & Ed. 0 0 0 0 0 Tech. Asst. NA 0 0 NA NA Water Quality 225,000 0 0 90,000 315,000 Monitoring SUM 1,098,196 0 328,366 90,000 $1,516,562* * Total does not include cost of technical assistance Source: Carty et al., 1991
Public meetings/workshops at which conservation tillage equipment was demonstrated
Fact sheet on proper disposal of agrichemicals
New media articles
Statewide meetings of the No-Till Council, a cooperative organization initiated by CES, agribusiness, and others
Demonstrations by CES of side-band application, in-row tillage, and dairy techniques
Tours of participating farms
Payment limit of $50,000
Strong technical assistance programs for fertilizer and pesticide management programs conducted by the CES
Perception on the part of the producers that the recommended BMPs would be economically beneficial
A eutrophication problem visible to the community
Funding limitations: the project stopped accepting applications in 1984 due to lack of funds
Producer's farm not located in the critical area
Inability of some producers to manage their share of the cost of BMP implementation
The use of no-till will be modified based on fuel costs (the higher fuel costs, the more no-till), the slug problem, and soil and climatic conditions (no till has a place when it is very wet or very dry).
The spillover from the project area to the rest of the county has been a major success of the project. Many farmers outside the project area wanted to participate in the project but were ineligible. Some of these producers have voluntarily adopted conservation tillage without cost share assistance through the RCWP.
Reduce the amounts of fertilizer and pesticides applied to cropland
Implement practices to manage manure applications so as to reduce nutrient losses
The original project goal was to have 100% of the critical area (13,00 acres) under contract by the end of FY 1984 with all contracts implemented by the end of FY 1989; this goal was later revised to treatment of 9,750 critical acres.
Soil erosion exceeding T value
Gully erosion (including ephemeral) is present
Concentration of animal wastes 1,500 feet or less from a stream
Need for better farm management with respect to application of fertilizer, pesticides, and animal wastes
Application of Criteria: Critical area designation for individual contracts was determined by soil conservationists using the above criteria on a field by field basis.
BMPs Utilized in the Project *:
Scouting has decreased pesticide applications as well.
Quantified Project Achievements:
Critical Area Treatment Goals Pollutant Source Units Total % Implemented Total % Implemented Cropland acres 13,000 87% 9,750 117% Dairies # 7 43% 5 60% Water # 160 48% 80 96%
Quality Plans Source: Appoquinimink River RCWP Project, 1987. RCWP Progress Summary for Fiscal Year 1987, form RCWP 3
Storm event samples were taken seasonally in Noxontown Pond, Silver Lake, and Shallcross Lake.
Ground water monitoring was added in 1984 to determine to what extent, if any, the installation of BMPs was affecting ground water quality.
Evaluate the impact of agricultural BMPs on water quality in the Appoquinimink watershed
Evaluate the impacts of improved animal waste handling, erosion and runoff control, fertilizer, and pesticide management on ground water quality
Silver Lake, Shallcross Lake, and Noxontown Pond: 1983 - 1986
Ground water: 1984 - 1986
Silver Lake, Shallcross Lake, and Noxontown Pond: 3 stations for each water body (2 within the lake and 1 at the outlet)
Silver Lake, Shallcross Lake, and Noxontown Pond: Monthly for baseline data / 3 storm event samples per year
Silver Lake, Shallcross Lake, and Noxontown Pond: (all stations) water & air temperature, biochemical oxygen demand (BOD), chemical oxygen demand (COD), acidity, alkalinity, hardness, pH, dissolved oxygen (DO), suspended solids (SS), dissolved solids (DS), orthophosphate (OP), total phosphorus (TP), organic nitrogen, ammonia-nitrogen (NH3-N), nitrite-nitrogen (NO2-N) and nitrate-nitrogen (NO3-N), chlorophyll a, biota, and coliform, fecal coliform (FC), and fecal streptococci bacteria
Silver Lake, Shallcross Lake, and Noxontown Pond: Biological monitoring consisting of periphyton and macroinvertebrate sampled monthly (April-Nov., 1985-86)
Silver Lake, Shallcross Lake, and Noxontown Pond: Point source monitoring - monthly sampling of point source discharges are conducted to supplement information in NPDES (National Pollutant Discharge Eliminiation System) Compliance Monitoring Reports, particularly for nitrogen and phosphorus discharge loads
Wiggins Mill Pond: The dam washed out in the spring of 1979 and was restored in 1984.
Noxontown Pond was dredged in 1984 through 1985 and may have contributed to increased organic nitrogen concentrations.
All water quality data were initially reduced to monthly means to reduce bias introduced by variation in sample number and period. Data summaries included univariate descriptive statistics using the SAS MEANS procedure and bivariate statistics using the SAS CORR procedure.
Analyses for trends were conducted by inspection of annual and seasonal mean concentrations and loading rates, and by evaluation of correlation coefficients to determine the significance of water quality changes over time.
Significant reductions in soil erosion and improved fertilizer and pesticide management practices have lowered the level of suspended solids in the river by 60%. In one pond, sediment levels have declined by 90% and total phosphorus has decreased by 65%.
The project team reports the following water quality trends. Delivery of suspended solids and nutrients from agricultural lands to surface streams has declined 90% from pre-RCWP levels. The delivery of total phosphorus to the stream has shown a similar decline. Both filtered and unfiltered total phosphorus have been reduced more than 60% from pre-RCWP levels. Orthophosphorus concentrations, however, increased somewhat over the first years of the study before declining to about 65% of pre-RCWP levels. Nitrogen loads to the stream have declined less than 25% from pre-project levels. Increased concentrations of organics (biochemical and chemical oxygen demand) are attributable to greater proportions of cropland remaining in vegetative cover from conservation tillage; however, these levels have not increased to a point where they are a concern (Carty et al., 1991).
Reduced suspended solids concentrations, and hence increased water clarity, have resulted in significant increases in algal growth in the downstream ponds. Nutrient concentrations have not varied significantly over the last four years of the project, indicating that pond sediments contribute sizable quantities of nutrients to pond waters. Water quality in the ponds can still be described as enriched (Carty et al., 1991).
The 1980 state sedimentation and erosion control law complemented RCWP in that all land disturbing activities required a plan to control off-site sediment. This included major and minor subdivision activity that occurred in the watershed (Carty et al., 1991).
Delaware's revised septic system regulations also complemented RCWP in that a site evaluation conducted by a licensed soils evaluator was required. The new standards prevent common failures encountered in the old method of total reliance on a percolation test (Carty et al., 1991).
During the project period, the Water Resource Agency developed resource protection area maps that identified recharge areas and wellhead areas in the county. Development in these areas was restricted by the county planning department (Carty et al., 1991).
Appoquinimink River RCWP Project, 1987. RCWP Progress Summary for Fiscal Year 1987, form RCWP 3.
Carty, C., J.J. Lakatosh, L.R. Irelan, B.L. Dworsky, R. Mulrooney, W. Ritter. 1991. Appoquinimink Rural Clean Water Program Ten Year Report. September 1991. Cooperators: ASCS, SCS, New Castle Conservation District, New Castle County-Water Resources Agency, CES, and the University of Delaware. 56p. plus appendices.
Dr. William Ritter
College of Agricultural Science
Department of Agricultural Engineering
Newark, Delaware 19717- 1303
USDA - SCS
2394 North Dupont Hwy
Middletown, DE 19709