Local beachgoers can bask and swim with more confidence this year, as an annual statewide survey of shoreline cleanliness is showing improvement for San Francisco’s coastal hot spots.
Heal the Bay, the group that conducts the survey, had Baker Beach on its “beach bummer” list as No. 7 and No. 8 in the state’s top 10 most polluted sites in 2010 and 2011, respectively. But this year, it dropped off the list entirely and received a B grade.
All told, every San Francisco beach received a B or A during summer weather, including Candlestick Point and Sunnydale Cove, which both scored higher than last year.
Aquatic Park — the popular swimming area where Hyde Street meets the water — received an A.
Two Candlestick Point areas — Windsurfer Circle and Sunnydale Cove — still have bacteria problems in wet weather. Both received F grades during the rainy season.
The report notes that San Francisco faces particular challenges in keeping beaches clean, especially during extreme rains, because of The City’s combined sewer and storm drainage system. Runoff generally receives two treatments before being discharged, yet storms often result in flows that consist of 94 percent treated storm water and 6 percent sewage.
San Francisco has an underground storage area to help control the heavy flows. However, there were 11 such “combined sewer discharges” in the winter of 2011-12, according to the report. This year’s scant rainfall resulted in 30 percent fewer such events in 2010-11.