Mammoth Creek Mercury Total Maximum Daily Load

Mammoth Creek, located in Mono County, CA, is listed on the Clean Water Act (CWA) Section 303(d) list of impaired waters due to exceedances of water quality standards for mercury.

The Lahontan Water Board has begun developing a TMDL for mercury in Mammoth Creek to address this impairment.  The goal of the TMDL is to reduce mercury concentrations to attain water quality standards established for the protection of all beneficial uses of these waters, including consumption of fish, and describe actions to achieve those reductions. The main source of mercury to Mammoth Creek is the historic Mammoth Stamp Mill site outside of the city of Mammoth Lakes. Mill City Tributary flows through this stamp mill site and into Mammoth Creek. Cleanup of this site is expected to be the main action identified in the TMDL.

To learn more about the Mammoth Creek Mercury TMDL including additional background information about mercury concentrations in Mammoth Creek, visit the Mammoth Creek Mercury TMDL Story Map.