Delaware: Trap Pond

Providing Technical Assistance and Better Managing Livestock Reduces Bacteria Levels

Waterbody Improved

  Excess bacteria from agricultural activities and failing septic systems impaired Trap Pond, one of Delaware's most important recreational resources. As a result, Delaware added the pond to its 1996 Clean Water Act (CWA) section 303(d) list of impaired waters. Providing technical assistance and implementing agricultural best management practices (BMPs) significantly reduced bacteria levels. Water quality improved, prompting Delaware to remove Trap Pond from its list of impaired waters in 2002.

Contact:

Robert Palmer
(robert.palmer@state.de.us)
Delaware Nonpoint
  Source Program
302-739-9922

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Figure 1. Trap Pond is in the Chesapeake Bay watershed in southern Delaware.

 

Figure 2. Trap Pond is surrounded by stands of bald cypress. Photo by Joanna Wilson, Department of Natural Resources and Environmental Control

Problem

Southern Delaware's Trap Pond is a tributary of Broad Creek,  which drains to the Nanticoke River, which in turn flows into the Chesapeake  Bay (Figure 1). Saunders Branch is the primary tributary to Trap Pond.

  Surrounded by majestic stands of bald cypress (Figure 2) in  the center of one of Delaware's state parks, Trap Pond supports abundant  wildlife and offers exceptional recreation opportunities. Trap Pond State Park  is home to the northernmost natural stand of bald cypress in the United States;  one tree in the park is estimated to be more than 200 years old, is 127  feet tall, is almost 25 feet around, and has a 62-foot branch spread. The area  also contains a 2,000-acre wetland, one of the largest surviving freshwater  wetlands in Delaware.

  Trap Pond was created in the late 1700s to power a sawmill.  The area's bald cypress was coveted for its rot-resistant wood and harvested  extensively throughout the 1700s. As a result, most of the bald cypress around  Trap Pond is second-growth. After logging ceased, landowners enlarged the pond  by installing drainage tiles to dry out the surrounding land for farming. In 1930,  the federal government bought Trap Pond and the farmland surrounding it and  brought in the Civilian Conservation Corps to develop the area for recreation.

  Water quality monitoring data collected in 1990 and 1991  showed bacteria counts as high as 700 colony-forming units (cfu) per 100  milliliters (mL). The pond routinely exceeded Delaware's water quality  standard, 100 cfu per 100 mL. A further study found that Saunders Branch, the  major tributary to Trap Pond, had elevated bacteria and phosphorus levels.  Sanitary surveys revealed that the two probable causes were direct discharges  from failing septic systems and manure from livestock that had direct access to  Saunders Branch or the drainage ditches feeding it. Based on this information,  Delaware added the 88-acre Trap Pond to the 1996 CWA section 303(d) list of  impaired waters for bacteria.

  Delaware completed a total maximum daily load (TMDL)  analysis for nutrients and dissolved oxygen in tributaries and ponds of the  Nanticoke River and Broad Creek watersheds in 2000. Delaware developed a  bacteria TMDL for the entire Chesapeake Bay drainage, including the Nanticoke  River watershed, in 2006.

Project Highlights

The first phase of the restoration project, conducted in the  very early 1990s, involved notifying property owners of their leaking septic  systems. The systems were quickly repaired or replaced, and the affected areas  of Saunders Branch responded immediately with decreased bacteria levels.

  The next phase addressed removing livestock access to  Saunders Branch and its drainages. A 1991 CWA section 319 grant funded the  salary of a Sussex County Conservation District conservation planner working  specifically in the Trap Pond watershed. Although removing livestock access to  drainage areas in the watershed was a key project component, the planner also  provided technical assistance to farmers who wanted help in implementing  agricultural BMPs and conducting nutrient management planning throughout the  Trap Pond watershed.

  The conservation planner worked with two large swine  operations that were immediately adjacent to Saunders Branch. The first  operation covered 1,000 acres and produced 9,800 finish hogs annually; the  second covered 100 acres and produced 1,200 finish hogs annually. The  conservation planner helped develop farm-wide conservation plans for both  farms.

Farmers installed BMPs on 29 poultry operations  in the Trap Pond watershed, including 23 manure storage structures, 19  composters and 2 dead bird incinerators. The Natural Resources Conservation  Service's (NRCS) Conservation Reserve Enhancement Program (CREP) and  Conservation Reserve Program supported planting of 2.4 acres of wildlife  habitat, 18 acres of hardwood trees and 5.0 acres of grass buffers. Sussex  County Conservation District planners continue to work with farmers throughout  the watershed to provide ongoing technical assistance to ensure improved water  quality.  

Results

Implementing  BMPs throughout the watershed quickly reduced bacteria levels in Trap Pond.  Monitoring data show that bacteria levels met the state water quality standard  of 100 cfu per 100 mL beginning in 1992. Water quality data collected through  1999 show that bacteria levels in Trap Pond remained well below the state  standards (Table 1). On the basis of these data, Delaware removed Trap  Pond from the 2002 CWA section 303(d) list of impaired waters for bacteria.

Partners and Funding

The Trap Pond project was a partnership involving the Sussex  County Conservation District, the Soil Conservation Service (now NRCS), and the  Delaware Nonpoint Source Program. Approximately $84,000 in federal CWA section  319 funds supported the costs of a Sussex County Conservation District planner  working strictly in the Trap Pond watershed. Additional funding was provided  through the NRCS' Environmental Quality Incentive Program and CREP, and the  state of Delaware's Conservation Cost Share Program.

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