SANTA CRUZ (CBS SF) — A stretch of beach near the wharf in Santa Cruz has the dubious distinction of having the worst water quality on the West Coast, according to a new report.

The Santa Cruz Sentinel reported Thursday that the environmental nonprofit group Heal the Bay placed Cowell Beach at the top of its annual “Beach Bummer” list.

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The annual report showed 92 percent of Bay Area ocean beaches have outstanding water quality and low bacterial pollution levels.

Heal the Bay analysts assigned A-to-F grades to beaches in San Francisco, San Mateo, Alameda, Contra Costa and Marin counties.

Out of 28 bayside beaches, 22 received A or B grades for the summer period, but there were pockets of pollution in San Mateo and San Francisco counties, according to the organization.

An A was given to 42 of 44 oceanside beaches from Marin to San Mateo counties.

The report analyzed weekly bacterial pollution levels at beaches statewide for three distinct time periods during 2013-14.

“Each year, we’ve seen an improvement statewide,” said Amanda Griesbach, a water quality scientist with Heal the Bay.

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The organization gave Marina Lagoon and Pillar Point Harbor, beaches in San Mateo County, failing grades.

Griesbach said there are still some problem areas on bayside beaches.

“There is still a bit of a discrepancy between bayside and oceanside beaches due to the water circulation,” she said.

A poor grade means beachgoers face a higher risk of contracting illnesses on a particular beach, according to the organization. Griesbach said researchers look for a higher concentration of bacteria in the water, because high bacteria levels can be an indicator of higher health risks.

Heal the Bay spokeswoman Randi Parent said the purpose of the report is to remind people to keep an eye on their favorite beaches and the water conditions.

Parent added the organization was happy with this year’s results. The organization attributed California’s severe drought as a major factor to the improved water quality at beaches statewide, because record-low rainfall reduced polluted runoff into the sea.

A Santa Cruz spokesman called the news of Cowell Beach disappointing but said officials are working to zero in on a cause.

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