San Rafael, CA – Water quality was excellent last summer at all Marin County beaches according to a new report from the environmental nonprofit Heal The Bay. The annual report rates water quality at beaches along the U.S. West Coast.
Arti Kundu of Marin County Environmental Health Services wades into Tomales Bay to check water quality.The summer day grades at the Marin County beaches were exemplary for a fourth straight year, with 100% of beaches receiving A and B grades. The grades came from sampling 26 beach sites over 31 weeks.
Marin’s water quality monitoring program, overseen by the Marin County Community Development Agency’s Environmental Health Services Division (EHS), gathered data from April 2021 through October 2021 from 26 bayside and oceanside monitoring locations. Twenty-four are marine beaches, and two are fresh water recreational sites. The beaches are managed by a variety of agencies.
When looking at the average grades of sites in a span of five years, 22 beach sites received A's, and only one location received a B. During the rare wet weather events from April through October, 15 sites received A and B grades and only four sites received either C, D, or F grades. The five-year wet weather beaches grade average is 81%.
Heal the Bay reports Marin received 20 inches of rain between April 1, 2021, and March 30, 2022, a 5% increase from the historical average. The full impact of the decreased rainfall in winter months is difficult to assess because most of the local beaches are not monitored during winter.
Rain alleviates drought conditions, but it also results in more pollutants, including bacteria, being flushed into streams, the bay, and the ocean. Pushed by rainwater, contaminants flow from streets in the form of trash, fertilizer, pet waste, metals, and automotive fluids.
Marin experienced 34 reported sewage spills that reached a body of water in the 2021-22 observation period amounting to 381,519 gallons of sewage reaching surface water. Three spills accounted for 91% total Marin’s record of spills in that period, falling under the jurisdiction of various sanitation districts, is on the California Environmental Protection Agency website.
Heal the Bay, based in Santa Monica, has analyzed water quality data at California beaches each year since 1991. The Beach Report Card is funded by grants from the Surf Industry Manufacturers Association and the Grousbeck Family Foundation. See the full report at HealtheBay.org.
Marin EHS has monitored ocean, bay, and freshwater sites since 2003 and posts sample results weekly. The samples are processed by the Napa-Solano-Yolo-Marin County Public Health Lab. The tests quantify the most probable number (MPN) of total coliform, E. coli, and enterococcus bacteria present in each water sample.
A warning sign is posted to alert the public if lab results indicate water samples exceed the State of California standards for recreational waters. The California Department of Public Health advises beach users to avoid contact with recreational waters where warning signs are posted. People in contact with elevated bacteria levels in recreational waters may become ill.
Heal the Bay recommends beach users never swim within 100 yards on either side of a flowing storm drain, creek, or river in any coastal waters during a rainstorm, and to stay out of the water for at least three days after a storm has ended.
Learn more about the testing program on the webpage.