EPA And California Board Agree On Impaired Waters List And Temperature Data Review.pdf

The United States Environmental Protection Agency (EPA) Region IX is approving the California State Water Resources Control Board's list of impaired waters for the periods 2014-2016 under the Clean Water Act (CWA) Section 303(d). This list includes water quality limited segments (WQLSs) and associated pollutants requiring a Total Maximum Daily Load (TMDL).

Key Points:

- Legal Requirements: The EPA reviewed California's submittal, focusing on their methodology, data use, and compliance with CWA and EPA regulations.
- Data Consideration: California utilized existing and readily available water quality data from various sources, including state reports and nonpoint source assessments.
- List Development: The State Board identified WQLSs based on the severity of pollution and intended uses, maintaining consistency with federal guidelines.
- Delistings: EPA concurs with the delisting of 191 WQLSs due to approved TMDLs.
- Temperature Data: EPA acknowledged challenges in evaluating temperature data from California Department of Fish and Wildlife (CDFW) and CDWR for potential impacts on fish migration. They suggested an "off-cycle" review to consider additional listings.
- Collaboration: The EPA values its collaboration with California and looks forward to continued partnership in water quality protection.

The EPA's approval is based on the State's thorough evaluation of data and adherence to listing requirements, ensuring that impaired waters are accurately identified for TMDL development.