Western States Water Newsletter

 Addressing Water Needs and Strategies for a Sustainable Future



Numeric Nutrient Criteria

On May 22, the EPA published a draft of Ambient Water Quality Criteria Recommendations for Lakes and Reservoirs in the Conterminous United States: Information Supporting the Development of Numeric Nutrient Criteria (85 FR 31184). This update to the national criteria recommendations will be the first in nearly 20 years. Once finalized, these recommendations will replace those published in 2000 and 2001 for lakes and reservoirs.

The summary of the draft recommendations states: “These draft national criteria recommendations are models for total nitrogen and total phosphorus concentrations in lakes and reservoirs to protect three different designated uses – aquatic life, recreation, and drinking water source protection – from the adverse effects of nutrient pollution.” The recommendations are based on stressor-response models that link nutrient pollution to the responses associated with the protection of designated uses. Specifically, the recommendations aim to reduce the incidence of harmful algal blooms that can occur as a result of nutrient pollution.

In a press release, EPA Assistant Administrator for Water David Ross said: “Under the Trump Administration, we are working with states, tribes and farmers from across the country to develop a wide range of tools that will reduce excess nutrients in America’s water bodies….This flexible approach is based on the latest scientific information and will help States and Tribes protect lakes and reservoirs from harmful algal blooms.”  EPA is accepting comments on the draft recommendations until July 21, with a specific request for scientific input. See www.regulations.gov, docket number EPA-HQ-OW-2019-0675.