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Home/Water Quality/East Bay Parks District County
Water quality testing site · East Bay Parks District County

Crown Bath House

Tested by East Bay Regional Park District, usually every 7 days.

A
Latest test · Monday, Oct 5, 2026
Water quality A: Clean

Taken 39 days ago. Results can take 1 to 3 weeks to be published, and many sites are tested less often in winter.

Enterococcus
10
per 100 mL
Safe limit
104
This test was 10% of the limit.
Usual here
8
The middle of 37 tests over the past year. This test is about normal for this beach.

Every bacteria in this test: Fecal coliform 11 · Total coliform 52 · Enterococcus 10. The grade follows the worst one against its own limit.

A
Last 30 days

Grade A over 5 tests from Sep 8, 2026 to Oct 5, 2026. None were over the limit.

Can I go in?

No recent test

The last test here was 39 days ago, too long ago to say anything about the water today. Some sites are tested only in summer. Stay out for 72 hours after any rain of 0.2 in or more, and check the county's status before going in.

History

Enterococcus over time

110100700Usual here: 8Safe limit: 104Friday, Dec 26, 2025: 0.15 in of rainSunday, Apr 12, 2026: 0.33 in of rainWednesday, Dec 17, 2025: 0.14 in of rainWednesday, Dec 31, 2025: 0.48 in of rainTuesday, Feb 17, 2026: 0.89 in of rainThursday, Jan 1, 2026: 0.55 in of rainSunday, Jan 4, 2026: 1.03 in of rainTuesday, Feb 24, 2026: 0.13 in of rainThursday, Nov 13, 2025: 1.27 in of rainWednesday, Feb 18, 2026: 0.25 in of rainMonday, Nov 17, 2025: 0.73 in of rainWednesday, Apr 1, 2026: 0.12 in of rainFriday, Dec 19, 2025: 0.24 in of rainThursday, May 28, 2026: 0.29 in of rainMonday, Jan 5, 2026: 0.77 in of rainMonday, Dec 22, 2025: 0.77 in of rainTuesday, Apr 21, 2026: 0.27 in of rainMonday, Apr 20, 2026: 0.87 in of rainFriday, Jan 2, 2026: 0.11 in of rainSunday, Feb 15, 2026: 0.24 in of rainWednesday, Apr 22, 2026: 0.16 in of rainWednesday, Feb 11, 2026: 0.15 in of rainWednesday, Dec 24, 2025: 0.76 in of rainFriday, Apr 10, 2026: 0.60 in of rainMonday, Apr 13, 2026: 0.11 in of rainMonday, Oct 13, 2025: 0.94 in of rainSaturday, Jan 3, 2026: 0.12 in of rainThursday, Nov 20, 2025: 0.27 in of rainSunday, Nov 1, 2026: 0.19 in of rainThursday, Feb 19, 2026: 0.56 in of rainThursday, Dec 25, 2025: 0.83 in of rainThursday, Oct 22, 2026: 0.22 in of rainSunday, Nov 16, 2025: 0.16 in of rainSaturday, Apr 11, 2026: 0.79 in of rainTuesday, Feb 10, 2026: 0.19 in of rainMonday, Feb 16, 2026: 1.06 in of rainSunday, Dec 21, 2025: 0.11 in of rainNovJan 2026MarMayJulSepNov
Rain of 0.2 in or more at the nearest airportsHover or tap a dot for its date and reading
Recent tests
  • A
    Monday, Oct 5, 2026
    Fecal coliform 11 · Total coliform 52 · Enterococcus 10
  • A
    Monday, Sep 28, 2026
    Fecal coliform 12 · Total coliform 160 · Enterococcus 10
  • A
    Monday, Sep 21, 2026
    Fecal coliform 21 · Total coliform 41 · Enterococcus under 10
  • C
    Monday, Sep 14, 2026
    Fecal coliform 39 · Total coliform 250 · Enterococcus 62
  • A
    Tuesday, Sep 8, 2026
    Fecal coliform 2 · Total coliform 30 · E. coli 10 · Enterococcus under 10
  • A
    Monday, Aug 31, 2026
    Fecal coliform 5 · Total coliform 41 · E. coli under 10 · Enterococcus under 1
  • A
    Monday, Aug 24, 2026
    Fecal coliform 18 · Total coliform 460 · E. coli 130 · Enterococcus under 1
  • B
    Monday, Aug 17, 2026
    Fecal coliform 97 · Total coliform 270 · E. coli 120 · Enterococcus 1
  • A
    Monday, Aug 10, 2026
    Fecal coliform 14 · Total coliform 480 · Enterococcus over 4
  • A
    Monday, Aug 3, 2026
    Fecal coliform 6 · Total coliform 240 · Enterococcus 2
What the numbers mean

Enterococcus and coliform bacteria live in the guts of people and animals. Health departments test for them because they travel with sewage, runoff and animal waste, so a high count is a warning that germs that do make people sick are likely in the water too. Clear water can still be contaminated: bacteria and viruses are too small to see.

San Diego County's DNA test (ddPCR) counts bacterial DNA instead of growing the bacteria in a lab, so it returns results the same day. Its numbers run higher than the older lab tests, which is why its safe limit is 1,413 rather than 104. The two are never compared on this page.

San Diego County's health department says swimming in water under an advisory can cause stomach illness, such as diarrhea and vomiting, and skin and ear infections. The EPA's national swimming guidelines are set at a level where about 32 to 36 of every 1,000 swimmers would get a stomach illness. A study of San Diego surfers found about 12 extra stomach-illness cases per 1,000 in wet weather, highest during rain and the day after, and back near normal 3 days later.

The grade is Nautical Nick's, built on the official limits: A is a quarter of the limit or less, B half or less, C under the limit, D over it, and F more than 10 times over. When a county posts an advisory or closes a beach, its sign is the final word.

Sources: California State Water Board beach test results; San Diego County Department of Environmental Health sample reports; Surfrider Foundation Blue Water Task Force; National Weather Service daily rain totals via the Iowa Environmental Mesonet (Concord/Buchanan, Hayward Air Term, Oakland, San Francisco Downtown, San Francisco Intl). Limits: California Code of Regulations, Title 17, Section 7958.