Ninety days of readings.
Log scale · MPN/100mLEach dot is one sample taken by the monitoring agency. The dashed brick line marks the EPA single-sample limit.
SafeCautionUnsafe
Common questions.
- Is Corcoran Lagoon Beach safe to swim today?
- Corcoran Lagoon Beach is currently inconclusive for swimming. Last sample is over 30 days old — too stale to be a reliable swim-safety indicator.
- When was Corcoran Lagoon Beach last tested?
- The most recent water-quality sample at Corcoran Lagoon Beach was collected on Mar 4, 2026 (90 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).
- What is the bacteria level at Corcoran Lagoon Beach?
- The latest reading at Corcoran Lagoon Beach shows 30-day enterococcus geomean at 10 MPN/100mL (EPA geomean limit: 35); enterococcus at 10 MPN/100mL (EPA single-sample limit: 104); and E. coli at 10 MPN/100mL (EPA single-sample limit: 235).
- Does rain affect water quality at Corcoran Lagoon Beach?
- Yes. Heavy rainfall washes bacteria and pollutants from land into the water, raising contamination risk for 24–72 hours. The past 48 hours recorded 0.00 in of rain; the past 72 hours recorded 0.00 in. Our advisory threshold is ≥1.00 in over 48h (or ≥0.50 in over 72h) for enclosed or storm-drain beaches.
- Where is Corcoran Lagoon Beach located?
- Corcoran Lagoon Beach is located in the Bay Area area of the San Francisco Bay region (coordinates: 36.9598°N, 121.9860°W). You can get turn-by-turn directions via Google Maps or Apple Maps directly from this page.
- How is the water quality data for Corcoran Lagoon Beach collected?
- Bacteria samples are collected by California state and county health agencies under the AB 411 Safe-to-Swim program and reported to the state's Safe-to-Swim database (data.ca.gov). Rainfall figures come from Open-Meteo forecast and archive data. Bay Area Swim aggregates both sources and updates every morning.
Also nearby
Data: California Safe-to-Swim (ODbL 1.0) · Open-Meteo — Precipitation (CC-BY 4.0) · Pipeline status