Because phosphorus degrades water quality and impairs aquatic ecosystems, Riverkeeper works with state and local government agencies to develop policies and practices that better control stormwater runoff and the phosphorus it carries. We also strive to educate decision-makers, planners and stakeholders on the impacts of phosphorus in surface waters and on Best Management Practices to protect our unfiltered drinking water supply.

Enhanced Phosphorus Removal Supplement

In 2008, the New York State Department of Environmental Conservation (DEC) added a supplemental chapter to the New York State Stormwater Management Design Manual requiring specific design standards for enhanced phosphorus removal in phosphorus-limited watersheds and projects. The goals of the supplement are to reduce stormwater runoff volumes and increase treatment with approved Stormwater Management Practices (SMPs). Riverkeeper submitted comments to DEC during the development of the supplement urging the State to require a rigorous monitoring program to verify pollutant removal efficiencies of SMPs and to encourage application of enhanced phosphorus removal standards in the West-of-Hudson Watersheds. While no reservoirs in the West-of-Hudson Watershed are currently phosphorus-limited, there is always the risk of future degradation and Riverkeeper support having uniform regulations for the entire NYC Watershed in place now.

Total Maximum Daily Loads

Section 303(d) of the Clean Water Act requires states to develop, and EPA to approve, Total Maximum Daily Loads, or TMDLs, for water bodies not meeting water quality standards (impaired waterbodies) or water bodies that are threatened or stressed. EPA defines a TMDL as the greatest amount of pollutant loading that a waterbody can receive without violating water quality standards. DEC has allocated pollutant loading from non-point sources, such as stormwater runoff, and point sources, such as wastewater treatment plants, to develop TMDLs for phosphorus for the all New York City drinking water reservoirs. Riverkeeper urges lead agencies to consider TMDLs during the review of proposed development projects in the NYC watershed so that phosphorus-limited reservoirs can achieve compliance with their TMDLs.