Napa River Pathogen TMDL

U.S. EPA gives final approval to TMDL for Pathogens in the Napa River Watershed
The U.S. Environmental Protection Agency has approved the Basin Plan amendment adopted by the Regional Water Board in November 2006, incorporating a TMDL and implementation plan for pathogens in the Napa River watershed. The TMDL was approved by the State Office of Administrative Law and became effective on December 6, 2007. The amendment is now part of the Water Quality Control Plan for the San Francisco Bay Basin (Basin Plan), the master planning document for water quality in the Bay Area. Electronic versions of the following documents are available upon request. However, in accordance with Section 11546.7 of the California Government Code, electronic versions cannot be posted online as they do not meet specified accessibility standards. For an electronic copy of the order, please contact the staff person listed at the bottom of this web page.

Water Board Resolution R2-2006-0079 (pdf)
Basin Plan Amendment (pdf)
Staff Report in support of Basin Plan amendment (pdf, 1.6MB)


The Napa River and its tributaries are listed as impaired by pathogens. The listing was made in response to observations of elevated bacteria in the river, which indicate the presence of fecal contamination and health risks to recreational users of the river from water-borne pathogens. Potential pathogen sources in the watershed include municipal stormwater, septic systems, sewer line leakage, pet waste, and livestock. The Napa River Pathogen TMDL examines this water quality problem, identifies sources of pathogen contamination, and specifies actions to create solutions. big dog wading in creek

For more information contact:

Laurie Taul
Agricultural Lands Program Section Lead
E-mail: Laurie