Beach Water Quality FAQ


Photo: Dan Sullivan

What are some symptoms of beachwater-related illness?
According to the Centers for Disease Control and Prevention, the most common symptom of beachwater illness is diarrhea. Gastrointestinal, skin, ear, respiratory, eye, neurologic, and wound infections are all possible illnesses.  

How do you get a beachwater-related illness?
Swallowing, breathing, or having contact with contaminated water. Submerging your head underwater or swallowing water increases the risk.

What kinds of tests are used in beach water quality monitoring?
Waters are tested for indicator bacteria: fecal coliform bacteria, total coliform bacteria, enterococci, and E. coli. Coliform bacteria are microorganisms that live in intestines and feces.

What about other contaminants besides bacteria, like pesticides or industrial pollution?
While San Francisco Bay waters and sediment are affected by many kinds of pollution, most don’t pose an immediate health threat. Long-term exposure could have cumulative health effects for those who spend a lot of time in the water.

What do I do if I get sick after going to the beach?
Visit your doctor or health care provider right away and call the Environmental Health department in the county where you visited the beach to report the illness.

Sometimes the beach stinks – does that mean the water can make me sick?

Unpleasant smells at the beach can be caused by a number of things, such as decaying seaweed. There isn’t necessarily a connection between smells and contaminated water.

What can I do to lower the risk of getting sick?
Keep your face and head out of the water and try not to swallow any water. Rinse off afterwards. Shallow water with low circulation can contain the highest levels of bacteria.

Where do the disease-causing bacteria come from?

Sewage spills are a prime cause. Blocked sewer lines can send sewage spilling into the streets and flowing into the Bay. Boats improperly dumping sewage contribute to the problem.

Rain can overwhelm sewage treatment plants, causing discharges of partially treated sewage into the Bay. Rain also can cause small sewage leaks into the storm drain system, elevating beachwater bacteria levels.

Animal feces (dogs, cattle, horses, and birds) can contribute bacteria in some locations.