On May 21, 2020, the U.S. Environmental Protection Agency (EPA) issued draft ambient water quality criteria recommendations for nutrients in lakes and reservoirs. The Clean Water Act (Act) mandates that EPA establish criteria for ambient water quality that accurately reflect the latest scientific knowledge on the impacts of pollutants on human health and the environment. These criteria protect three distinct water uses; they are aquatic life, recreation and drinking water source protection.


States and tribal governments use these criteria (or others based on them) to develop their own standards to protect human health and the environment. These regulatory entities can modify water quality criteria to address site-specific conditions or establish criteria based on other scientifically defensible methods. Nutrient pollution stimulates excess growth of algae, which can limit the recreational use of lakes and reservoirs. Overabundant algae also increase the amount of organic matter in a lake or reservoir, which, when decomposed, can depress dissolved oxygen concentrations below levels needed to sustain aquatic life.


EPA will be collecting comments on the draft criteria for a 60-day period which ends on July 21, 2020. Comments should reference Docket ID No. EPA-HQ-OW-2019-0675 and be submitted via the Federal eRulemaking Portal at https://www.regulations.gov and typing in the docket ID number noted. When finalized, these criteria will update previous criteria established in 2000 and 2001. The new criteria may then be adopted by States and tribal governments implementing the CWA. However, these States and tribal governments are not required to adopt the revised criteria. A copy of the Federal Register notice announcing the proposed criteria can be found HERE.