Tijuana Slough National Wildlife Refuge: Tijuana Estuary mouth
Tested by San Diego County, usually every 7 days.
Taken 17 days ago. Results can take 1 to 3 weeks to be published, and many sites are tested less often in winter.
Every bacteria in this test: Total coliform over 16,000 · Fecal coliform 4,800 · Enterococcus 660. The grade follows the worst one against its own limit.
Grade D over 5 tests from Sep 30, 2026 to Oct 27, 2026. 3 were over the limit.
Stay out until a retest passes
The latest test was over the safe limit. No one can say how long that lasts: the beach is cleared when a new test comes back under the limit. This site is usually tested every 7 days, so a newer test may already be taken and not yet published.
County status: Closed, checked Friday, Nov 13 (San Diego County Department of Environmental Health and Quality). The county’s posting is the final word.
Likely sewage from the Tijuana River
Sewage-tainted water from the Tijuana River reaches this shore, and San Diego County keeps beaches here closed when it does.
Enterococcus over time
- Tuesday, Oct 27, 2026Total coliform over 16,000 · Fecal coliform 4,800 · Enterococcus 660
- Tuesday, Oct 20, 2026Total coliform 8,200 · Fecal coliform 1,600 · Enterococcus 600
- Tuesday, Oct 13, 2026Fecal coliform 8,000 · Total coliform over 16,000 · Enterococcus 1,8001.20 in of rain in the 3 days before
- Tuesday, Oct 6, 2026Fecal coliform under 2 · Total coliform 8 · Enterococcus 4
- Wednesday, Sep 30, 2026Fecal coliform 220 · Total coliform 1,000 · Enterococcus 12
- Tuesday, Sep 22, 2026Fecal coliform 30 · Total coliform 160 · Enterococcus 24
- Tuesday, Sep 15, 2026Fecal coliform under 2 · Total coliform under 20 · Enterococcus 4
- Tuesday, Sep 8, 2026Fecal coliform 14 · Total coliform 120 · Enterococcus 34
- Tuesday, Sep 1, 2026Fecal coliform 2 · Total coliform 20 · Enterococcus 22
- Tuesday, Aug 25, 2026Fecal coliform 6 · Total coliform 60 · Enterococcus 86
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 (San Diego/Montgomery Fld, San Diego/Lindberg, San Diego/Brown). Limits: California Code of Regulations, Title 17, Section 7958.