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Reducing Phosphorous Makes Sense - Spring 2010 Issue

(by James Tierney, Assistant Commissioner for Water Resources)

Excess phosphorus is the leading cause of water quality impairment in New York State. There is a proven and cost-effective way to reduce phosphorus pollution contained in legislation pending before the State Senate and Assembly (S.3780/A.8914) that would dramatically reduce phosphorus in lawn fertilizers and dishwasher detergents. Cities, towns, businesses, rate-payers, farmers and plant operators will likely save money if this legislation is adopted. This is because the Clean Water Act forces increasingly stringent and expensive phosphorus treatment technology upon State Pollutant Discharge Elimination System (SPDES) permitted facilities to improve waters "impaired" by phosphorus, including sewage treatment plants, municipal storm sewer systems, concentrated animal feeding operations (CAFO's), industrial facilities and construction sites.

Why not first try to improve water quality by taking unnecessary phosphorus out of lawn fertilizers and dish washing machine detergents that ultimately end up in the environment? One major study found that a low phosphorus fertilizer ordinance in the City of Ann Arbor, Michigan reduced phosphorus loadings by 22 percent. That is a very significant reduction that can mean the difference between water that complies with standards and one that violates the law.

Phosphorus causes problems at very low concentrations. The Department of Environmental Conservation (NYSDEC) has set the "guidance value" for phosphorus at 10 to 20 parts per billion in a number of New York's waters. (Think 10 or 20 cents relative to $10 million.) The low concentrations at which phosphorus causes harm gives one a sense of the usefulness of also addressing phosphorus in dishwashing detergent - which generally ranges from one to four percent phosphorus by weight (think $100,000 to $400,000 relative to $10 million.) Effective substitutes exist to replace phosphorus in household dishwashing detergents and they should be developed for institutional dishwashing detergents.

There is more than enough phosphorus in our soils. Additional phosphorus is rarely needed for lawns and many lawn care companies use low phosphorus fertilizers. Westchester County has banned it, as have other states and local municipalities.

Excess phosphorus is the prime cause of algae blooms in fresh water. As bacteria consume the algae bloom they also multiply rapidly and extract most of the oxygen in the water - creating a low oxygen "dead zone." Water looks, smells and tastes bad as low-oxygen biology predominates - causing metals, and more phosphorus, to be released from bottom sediments. In drinking water supplies, the dead algae and bacteria react with chlorine during disinfection to form a class of regulated chemicals that are suspected carcinogens and are cited in medical studies as contributing to increased levels of miscarriage. More organic material in the drinking water from algal and bacteria blooms also can shield pathogens from various disinfectant processes.

Why load all this phosphorus into the environment if it serves no useful purpose and drives up costs for hard-pressed municipalities and businesses? It is time to pass this common sense law.

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