The Environmental Health staff advises swimmers that levels of bacteria can rise significantly in ocean and bay waters adjacent to storm drains, creeks and rivers during and after rainstorms. The elevated levels of bacteria can continue for a period of at least 3 days depending upon the intensity of the rain and the volume of the runoff. Swimmers should avoid coastal waters impacted by discharging storm drains, creeks and rivers, and beach users should avoid contact with any runoff on the beach during dry or wet weather conditions.