Berkeley Aquatic Park — Middle Lagoon

Each dot is one sample taken by the monitoring agency. Dashed lines mark each indicator's EPA single-sample limit; bars along the bottom show daily rainfall.

Common questions.

Is Berkeley Aquatic Park — Middle Lagoon safe to swim today?

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Berkeley Aquatic Park — Middle Lagoon is currently safe for swimming. Recent samples within safe ranges.

When was Berkeley Aquatic Park — Middle Lagoon last tested?

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The most recent water-quality sample at Berkeley Aquatic Park — Middle Lagoon was collected on Sep 10, 2026 (12 days ago). California monitoring agencies test Bay Area beaches weekly during swim season (roughly May through October).

What is the bacteria level at Berkeley Aquatic Park — Middle Lagoon?

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The latest reading at Berkeley Aquatic Park — Middle Lagoon shows enterococcus at 20 MPN/100mL (EPA single-sample limit: 104).

Does rain affect water quality at Berkeley Aquatic Park — Middle Lagoon?

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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 Berkeley Aquatic Park — Middle Lagoon located?

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Berkeley Aquatic Park — Middle Lagoon is located in the East Bay area of the San Francisco Bay region (coordinates: 37.8509°N, 122.2976°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 Berkeley Aquatic Park — Middle Lagoon collected?

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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.