May 31, 2013 -- The Water Environment Research Foundation's (WERF) new Nutrient Modeling Toolbox (NMT) was recently developed to help communities, state agencies and permit holders who set limits on nutrients (such as nitrogen and phosphorus), protect and maintain their local waterways.
As numeric nutrient criteria are developed by local governments, the EPA has defined three categories of approaches: 1) Reference Condition Approach, 2) Stressor-response Analysis, and 3) Process-based (Mechanistic) Modeling. The agency has provided guidance for developing nutrient criteria using the reference condition and stressor-response approaches; however, similar guidance is not currently available for the modeling approach.
This new WERF research report presents guidance and tools to use models to set waterbody-specific nutrient goals, including Numeric Nutrient Criteria and allowable nutrient loadings. It provides a mechanism that can quantitatively link nutrient loads to water quality and ecological response indicators on a site-specific basis. It allows the user to evaluate and select a model that recognizes a waterbody’s responses to nutrients depending on site-specific characteristics such as morphology, hydrology, turbidity, temperature, and other available data.
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