Appoquinimink River TMDL Adopted

The Environmental Protection agency (EPA) adopted the Appoquinimink River Total Maximum Daily Load (TMDL) regulation on December 15, 2003 after a November 10 public meeting where the proposed TMDL was presented at the Brick Mill Elementary School in Middletown.

The relatively technical presentation covered the history of the TMDL, the way it was developed, and the proposed load allocations for point source and non-point sources in the watershed.  Tetra Tech, working for the EPA , reviewed the technical aspects of the model used to simulate the water movement and water quality within the watershed.  Using the model as a predictive tool, they determined the magnitude of the load reductions that will be needed to ensure all applicable water quality standards will be met.

Based on the model, the EPA proposed a 60% reduction in land-based, non-point source contributions to the Appoquinimink River and proposed no change to the watershed’s sole point source, New Castle County’s Water Farm 1 spray irrigation wastewater treatment facility.  The current nutrient contribution from the facility is only a small portion of the overall amount of nitrogen and phosphorus entering the Appoquinimink River from all sources.   Water Farm 1, located near Odessa, works by treating water in open lagoons, then spraying it into a field of reeds that absorb any remaining pollutants.  The excess treated water is discharged into the creek.  The EPA acknowledges non-point source reductions will be more difficult to regulate than point sources, such as Water Farm 1.  Nonpoint sources have a greater effect on water quality during wet weather, when there is a lot of runoff while point sources have more of an effect during dry weather when there is less water to dilute pollutants entering the waterway.

Residents, state, county, and elected officials, and representatives from several non-profit organizations, such as the Sierra Club, Green Delaware, and Southern New Castle County Alliance attended the meeting.  Many people in attendance were concerned about rumors that the New Castle County Water Farm 1 was seeking an increase in the amount of nutrients they are allowed to release in the Appoquinimink River; however the EPA recommendations in the draft kept the current restrictions in place.  Attendees commented they would like to see EPA reduce the amount of pollution coming from Water Farm 1.

Several people were concerned the TMDL as written would not be enforceable in any meaningful way for non-point source reductions. 

The presentation made by EPA and Tetra Tech revealed the model they had used to determine the reductions that would be required were based on data from 1991.  EPA recently obtained more current data and was working to update the model at the time of the public meeting, however residents were unable to review the TMDL with the more recent data.  EPA agreed that the public comment period would have been more helpful if citizens had been able to see the up-to-date information.  Officials and residents requested another public meeting to review the final document before it goes into effect.  Because of a court decision, EPA is obligated under court order to produce the final TMDL by mid-December.

EPA accepted public comments regarding the proposed regulation until November 17, 2003, and formally adopted it December 15, 2003.