On August 20, ASDWA and ACWA submitted joint comments to EPA on the “Draft Updated Ambient Water Quality Criteria Recommendations for Lakes and Reservoirs of the Conterminous United States: Information Supporting the Development of Numeric Nutrient Criteria (Draft LNNC).” These new recommendations will replace the previous recommendations published in 2000 and 2001 to provide a probabilistic modelling approach for deriving numeric criteria that will help states achieve their water quality standards goals to protect drinking water sources, recreational uses and aquatic life in lakes and reservoirs from the adverse effects of nutrient pollution.
The ASDWA and ACWA comments include 27 pages of recommendations and questions for EPA that mostly pertain to state clean water programs’ use of the models to apply estimates from National Lakes Assessment (NLA) data for site specific circumstances and meeting state nutrient management goals and EPA objectives, and that may have the potential to derive criteria that is less protective than existing state standards. The detailed comments recommend EPA support for (and collaboration with) states to review and implement the Draft LNNC,. The drinking water comments on pages 9 -12 provide information about nutrient related impacts to drinking water sources and treatment, and the need for nutrient criteria derived from the Draft LNNC to protect public health and the economy. The drinking water section includes recommendations for EPA to consider: occurrence of other cyanotoxins in addition to microcystin; impacts from algae blooms and organic matter in treatment processes to address disinfection by-products and taste and odor issues; more stringent state water quality criteria; future sources of drinking water; using state and local data to fill gaps in the EPA model, and more. For more information about the Draft LNNC, visit the EPA website.