What do the tests mean?
The tests measure the amount of coliform and enterococcus bacteria. A beach will be posted if a single sample at a beach measures a high level of either of these bacteria, said John Van Rhyn, water quality expert with the county’s Environmental Health Department.
Signs could also be posted if the tests, averaged over five consecutive weeks, show levels elevated enough to cause some concern, he said.
Once a beach is posted, health officials must continue to monitor the area. The signs come down only after a beach gets a clean bill of health, Van Rhyn said.
Posting a beach is different from a beach closure. When a beach is posted, 300 feet of beach are marked with signs which state, in both English and Spanish, that there might be a potential health risk. A beach closure is marked with signs which emphatically warn, “Keep out,” Van Rhyn said.
A beach would be closed only if officials were certain of a serious health risk, such as a sewer spill, Van Rhyn said.
Van Rhyn noted that a posted beach could still be shut down. Lifeguards have expressed concern about contaminated water and may prohibit swimming so as not to put themselves at risk.