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Water Quality
Water Quality Standards and Classification
Nutrient Criteria
In aquatic ecosystems, there certainly can be too much of a good thing. Waterbodies need nutrients such as nitrogen and phosphorous, but over-enrichment creates problems. When human activities are to blame, this nutrient overload is called cultural eutrophication. A classic example occurs when phosphorus from human, farm animal, and industrial wastes finds its way into lakes and rivers, spurring rapid growth in algae. The resulting algal bloom chokes off the oxygen supply for other plants and wreaks havoc on an ecosystem.
Most states have established narrative standards for acceptable levels of nutrients. New Hampshire, for example, includes this statement in its regulations: "(Lakes and ponds) shall contain no phosphorus in such concentrations that would impair any usage assigned to the specific class involved, unless naturally occurring." While useful, such standards are too vague from EPA's perspective. EPA wants states to develop, by the end of 2004, far more specific numeric standards for distinguishing natural nutrient enrichment in a waterbody from the damaging over-enrichment caused by pollution.
NEIWPCC is doing all it can to assist the states in this effort. In 2003, we assisted the North American Lake Management Society (NALMS) in conducting a survey that queried states about their approach to the nutrient criteria issue. And since 1998, NEIWPCC has coordinated meetings and organized workshops for New England's Lakes, Rivers, and Estuaries Regional Technical Assistance Groups. These RTAGs, as they're known, were established by EPA as a means of bringing together a region's EPA and state representatives to work on criteria development.
Using a grant from EPA, NEIWPCC also funds and manages the work of a contractor, ENSR International, which is collecting, classifying, and evaluating data on nutrients in the region's water bodies. Available for download are several of ENSR's reports, including one that compiles all the nutrient data that states and the U.S. Geological Survey have developed over the past 10 years.