California Beach Water Quality

Advisories in California are issued and lifted by California State Water Resources Control Board and the local health departments that work with it, often within a couple of days, so the current answer is theirs: California Safe to Swim publishes the statewide beach water quality map and the county postings behind it. This page gives you what California monitors, how its programme compares with the rest of the country, and the link to that page. EPA puts the division plainly: "States, Tribes, territories and local governments decide whether to open or close a beach."

At California Safe to Swim, which publishes the statewide beach water quality map and the county postings behind it. Link verified 2026-09-02. The sign at the beach entrance outranks any website, including that one, because it was put there by someone who looked at that specific water. EPA's own advice: "Be aware of any signs indicating the beach is closed or the water is not safe because of bacteria, riptides or other hazards. In areas that are not monitored regularly, choose swimming sites in less developed areas with good water circulation, such as beaches at the ocean. Avoid swimming at beaches where you can see discharge pipes or at urban beaches after a heavy rainfall."

In EPA's 2025 swimming season report, California had 252 BEACH Act beaches. 248 of them were program beaches, meaning a programme reports notification actions to EPA at least once a year, and 248 of those were sampled for bacteria at least once during the season. Every program beach in the state was sampled. A further 4 beaches EPA counts sit outside the programme entirely. Those are EPA's counts.

Fecal indicator bacteria, which are not themselves the thing that makes people ill. They are counted because they are cheap and fast to measure and they track the presence of sewage and animal waste. Marine programmes generally count enterococci and Great Lakes programmes generally count Escherichia coli. EPA describes what a result actually implies: "In the event that beaches are closed or advisories are posted, it is most often because water samples for certain bacteria indicate that harmful bacteria, viruses, protozoa, or parasites are likely present in the waters." Nothing in a bacteria count says anything about chemicals, jellyfish, rip currents or algal toxins, each of which is a separate programme.

California State Water Resources Control Board does not publish a single statewide monitoring season. Sampling in most states is concentrated in the swimming months and thins out or stops outside them, which matters because an unposted beach in the off season usually means nobody sampled it rather than that a sample came back clean. California Safe to Swim is the place to see what is currently being sampled.

No, and this is the single most important thing on this page. An absent advisory can mean the water was sampled and the result was under the state threshold, or that the beach is one of the 0 program beaches in California that nobody samples, or that the sample was taken before the rain that arrived last night. Results take about a day to come back from the lab, so even a fresh posting describes yesterday's water. EPA links digging in sand to illness too: "The EPA has linked digging in beach sand to an increased risk of gastrointestinal illness."

At California Safe to Swim, published by California State Water Resources Control Board and linked above. Advisories are lifted as soon as a follow up sample clears, often within a day or two, which is why the agency's own page is the place to read them rather than any copy; EPA says the same about its own national database: "States, territories and Tribes receiving beach grants submit information on beach monitoring and closures and advisories to the EPA, but they are only required to submit that information once a year, although some report more frequently. Therefore, BEACON has information about the previous year and earlier, but it does not have current information about advisories or closings." This page carries the durable half: what is monitored, by whom, and how much of the coast that covers.

CDC: "You can get swimming-related illnesses if you swallow, have contact with, or breathe in mists of water contaminated with germs. The most common swimming-related illnesses are diarrhea, skin rashes, swimmer’s ear, pneumonia or flu-like illness, and irritation of the eyes or respiratory tract." EPA names the groups most affected: "Children, the elderly and people with weakened immune systems are the most likely populations to develop illnesses or infections after coming into contact with polluted water, usually while swimming." The exposure route that matters most is swallowing water, which is why EPA's practical advice is about your head rather than your skin: "When waterborne pathogens are present, most swimmers are exposed when they swallow the water. You will be less likely to get sick if you wade or swim without putting your head under water." That is the two federal agencies quoted directly.

From EPA's BEACON Dynamic National Report, the public face of the database that BEACH Act states report into. We read the 2025 swimming season table as it stood on September 02, 2026 and stored the counts unchanged; a US Government work in the public domain. California is one of 16 states that both enrol and sample nearly every beach EPA counts. Every count on this page is EPA's.