The members
of CMSA are:

• San Rafael Sanitation District
• Sanitary District No. 1 of Marin County
• Sanitary District No. 2 of Marin County
• The City of Larkspur

As a regional agency dedicated to the health, our expert staff focuses all of its skill and effort on providing first quality wastewater related services for the residents, businesses, and environment of our communities.

Central Marin Sanitation Agency is a joint powers agency or JPA formed by its member agencies, which are special districts and municipalities in the San Rafael and Ross Valley areas of central Marin County, California. CMSA was formed for the purpose of constructing and operating a wastewater treatment plant located in San Rafael.

The publicly owned and operated treatment plant treats an average of about 11 million gallons of wastewater a day.

We carry out a variety of tours and educational programs for students and adults.

We are both regulated and regulators. Our discharge quality to the San Francisco Bay is monitored and regulated by the San Francisco Regional Water Quality Control Board (SFRWQCB) and we in turn regulate commercial, industrial, and institutional discharges to the sewage collection system. The terms of regulation of our discharge to the Bay are outlined by our NPDES permit as measured by detailed laboratory results.