Ocean and Beach Monitoring | SFPUC

General Beach Monitoring Information

• Seventeen sites are monitored weekly at beaches around the perimeter of San Francisco where water contact recreation is common:
  • Candlestick Point State Recreation Area (Sunnydale Cove, Windsurfer Circle, and Jackrabbit Beach)
  • Islais Creek (Islais Landing)
  • Crane Cove Park
  • Mission Creek (Berry Street at Kayak pier)
  • Aquatic Park (Hyde Street Pier and Aquatic Park Beach)
  • Crissy Field (Crissy Field East and Crissy Field West)
  • Baker Beach (Baker Beach East, Baker Beach at Lobos Creek, and Baker Beach West)
  • China Beach
  • Ocean Beach (at the foot of Balboa Street, at the foot of Lincoln Way, and the foot of Sloat Boulevard)
• Samples are analyzed for three different bacterial indicators of impaired water quality (total coliform, Escherichia coli/fecal coliform, and enterococcus) by the quanti-tray and membrane filtration methods.
• Results are available the day after the samples are taken because it takes time to culture the bacteria in order to obtain an accurate estimate of their abundance. Beaches are posted and the public is notified 24 hours after an elevated concentration of bacteria occurs. This is done in case the elevated bacteria concentrations persist.
• In order to provide as rapid a response as possible the City proactively posts (and de-posts) beaches and makes public notifications based upon preliminary bacteria counts made available before final results are confirmed. The public is better served overall by timely notifications based upon preliminary counts than by the procedural delay needed to act upon confirmed counts.
• Beach users concerned with the potential for exposure to elevated bacteria concentrations are advised to avoid water contact recreation during and immediately after rain events.

What Causes Elevated Bacteria Counts?
The causes of elevated bacteria counts not associated with combined sewer discharges are not always clear; they may be related to storm runoff from the beaches themselves that might contain human or animal feces, decaying plant or animal material, or naturally occurring sand or soil bacteria.

Because elevated counts for a single indicator may be spurious and historical data indicate that such counts are typically not persistent, we have adopted a confirmation approach to posting beaches that lack sources of pollution. See the Rationale for Confirmation before Posting. For those beaches, confirmation is provided by a second elevated indicator in the same sample, an elevated indicator at a linked station (if applicable), or an elevated indicator in a repeat sample.

Information about Combined Sewer System Discharges:

• San Francisco’s Combined Sewer System (CSS) is unique in coastal California. Our combined sewer system offers significant environmental benefit compared to a “separate” sewer system because it captures and treats both stormwater and urban street runoff in addition to commercial, industrial and sanitary wastewater.
• During heavy rain events, the combined sewer system can reach capacity and discharge into coastal waters. When this happens, the effluent is typically comprised of 94% treated stormwater and 6% treated sanitary flow. A system of underground storage, transport, and treatment boxes minimizes the number of combined sewer discharges.
• All stormwater receives primary treatment before being discharged through a designated outfall. Combined sewer discharges do not contain raw, untreated sewage.
• We implement best management practices to maximize storage and treatment and minimize shoreline discharges.

Who Administers the Beach Water Quality Monitoring Program?
The SFPUC jointly administers the beach water quality monitoring program with the San Francisco Department of Public Health (SFDPH). Both agencies participate in sample collection; the SFPUC Microbiology Laboratory performs bacteriological analyses.

SFPUC is responsible for public notification when water quality does not meet State standards for water contact recreation, while SFDPH is responsible for ensuring compliance with the California Sanitation, Healthfulness and Safety of Ocean Water-Contact Sports Areas Regulations, Title 17, California Code of Regulations.