Contra Costa County beaches received perfect summer water-quality grades at monitored locations, joining four other counties at the top of the list, according to the 2013 End of Summer Beach Report Card® issued Thursday by the environmental group Heal the Bay.
Overall, the water quality of California beaches was excellent for the seventh consecutive summer.
In its latest survey, Heal the Bay assigned an A-to-F letter grade to 450 beaches along the California coast based on levels of bacterial pollution reported weekly from Memorial Day to Aug. 21. This summer, 96% of sites earned A or B grades, the same percentage as in last year’s seasonal report.
Heading into the end-of-summer Labor Day holiday, ocean users can take comfort in steadily improving water quality grades over the past decade. The completion of dozens of infrastructure improvements to divert and/or treat pollute runoff has played the major role in rising grades during the past 10 years.
Some 14 beaches statewide scored D or F grades in this summer’s report. Los Angeles County, which historically has the worst water quality in the state, and San Mateo County accounted for the majority of the D and F grades.
Poor water quality is often found at beaches near flowing storm drains, piers and enclosed water bodies with inadequate circulation. The worse grade a location receives, the greater the risk of such serious illness as stomach flu, ear infections, upper respiratory infections and skin rashes.
The beaches scoring failing marks this summer: Los Angeles County’s Cabrillo Beach-harborside; San Mateo County’s Pillar Point Harbor, Aquatic Park and Lakeshore Park; Santa Cruz County’s Cowell Beach; Monterey County’s Stillwater Cove and Humboldt County’s Clam Beach County Park.
The other counties with perfect summer water-quality grades at monitored locations this year are, Ventura, Alameda, San Francisco and Mendocino.
For a county-by-county breakdown with information on regional trends and specific beaches, please visit healthebay.org/brcsummer