Marin Water takes many steps to ensure the water delivered to your service line is of the highest quality including managing our watershed lands and reservoirs, treating the water, operating and monitoring a complex distribution system, and maintaining and upgrading our facilities. Every year, we release a Water Quality Report that provides information about our water sources, treatment process, water testing results, and more.
Our core mission is to provide fresh, high-quality drinking water at a reasonable price. Our local water supply means you can be sure your water is clean, fresh and sustainably sourced. Our water meets or exceeds all state and federal drinking water standards, and costs most customers about two cents per gallon.
Cross-connections, a temporary or permanent location between public drinking water and a consumer's water system, could potentially introduce contamination or pollution into the public or private drinking water system.
Irrigation systems, hose bibs, boilers, radiant heat systems, wells, docks, ponds, fountains, pressure boosting systems, pools, spas, graywater systems, rainwater collection systems, reclaimed water, and solar heating systems are just a few examples of hazards that need to have backflow protection.
There are four types of assemblies. If the district has done a survey of your residence or business you will receive a letter letting you know which type of assembly is best suited for you and the location of where it must be installed. There are many brands to choose from, but your assembly must be on Marin Water's list of approved backflow assemblies formulated by the University of Southern California Foundation for Cross-Connection Control and Hydraulic Research.
Having a backflow preventer installed at your meter protects only the public water system. There may be unprotected cross-connection issues within your property. You may email us at Backflow@MarinWater.org if you have any questions or call 415-945-1488. Or you may refer to our list of Certified Testers to find a cross-connection specialist that can meet with you and conduct an in-depth survey of your home or business.
Scheduling annual inspections is required in order to ensure the public drinking water system is protected from possible contaminants. A visual inspection of an air gap is sufficient, but backflow assemblies must be tested by a Certified Backflow Prevention Assembly Tester using a properly calibrated gauge.
Backflow Assembly Testers
Backflow Assembly Testers play a vital role of keeping the public drinking water system safe and clean by preventing backflow. Marin Water relies on backflow assembly testers to submit accurate information in a timely manner.
All new testers must submit an online application in order to be added to the approved Marin Water Testers List. After submitting the application, please scan and email copies of current Certifications and Gauge Verification to Backflow@MarinWater.org. After we have received all the documents, we will process the application and schedule a hands-on demonstration, held in April and October. Submit an online application here.
Online Test Report
Submit an online test report here.
For more information, please call 415-945-1488 or email us at Backflow@MarinWater.org.
Every year Marin Water cleans some of its water mains to remove built-up sediment so we can maintain the high-quality water you expect from us.
To clean a water main, we turn on select hydrants along a section of the water main. Water comes out of the hydrants with enough velocity to clean the water main. We also collect water quality samples as part of the water main cleaning process to ensure our water meets the highest standards.
During the cleaning process, you may notice water in the streets as well as slight drops in water pressure. After the cleaning, you may notice air in your water lines at first, or a brief discoloration of water in your own plumbing. If you notice these effects, we recommend running cold water for a short time to remove any loose sediment in the pipeline that runs from our water main to your home.
For questions or additional information about water main cleaning in your area, contact us at 415-945-1438 or email us at info@MarinWater.org.