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Water Quality

Special Projects

  • NY Tidal Wetlands
  • NY & NJ Nutrient Assessment
  • New England Lakes and Ponds (NELP)
  • Cyanobacteria Workshop
  • Partnerships: Long Island Sound Total Maximum Daily Load
  • 303(d)/TMDL National Webinar Series
  • Water Quality | Total Maximum Daily Load

    TMDL programs are a highly effective means of reaching NEIWPCC's main goal: cleaner water. As a result, we are very involved in TMDL work being done throughout our member states.

    Fundamentally, the TMDL process is straightforward: States are required by the Clean Water Act to identify water bodies that are failing to meet their water quality standards. The regulations then require that any impaired waterbodies be analyzed to determine the daily amount, or load, of a pollutant they can absorb without significantly impairing the health of the water. Once that amount is determined, the states use it to establish a TMDL, which specifies the acceptable load, outlines where the pollutant is coming from, and specifies where and when reductions will be made so the load isn't exceeded. The TMDL is then submitted to EPA for approval.

    While the process is straightforward, executing it can be complex, problematic, and expensive. For years, NEIWPCC has been assisting states with their TMDL programs. NEIWPCC is contributing to TMDL work underway on many waterbodies in New England and New York State, such as the New York-New Jersey Harbor and Long Island Sound.

    NEIWPCC also works on TMDL projects with broader applications. For example, NEIWPCC worked with the U.S. Geological Survey to develop a New England Regional SPARROW (Spatially Referenced Regressions on Watershed Attributes) model, which can be extremely helpful in developing nutrient TMDLs. NEIWPCC worked with all of its member states on the Northeast Regional Mercury TMDL to reduce atmospheric deposition of mercury and work toward eliminating fish consumption advisories. In the policy arena, NEIWPCC monitors EPA's TMDL guidance, and submits comment letters, if necessary, providing feedback to EPA from our member states.

    For more information, contact Dan Peckham, coordinator of our TMDL programs.

    To access EPA's extensive information on TMDLs, go to


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