In 1999, beach pollution prompted at least 6,160 days of closings and swimming advisories at ocean, bay, Great Lakes, and some freshwater beaches. Most likely, many additional cases of beach pollution went undetected due to lax monitoring standards in some states and territories. The large number of closings overall, however, shows that pollution is a persistent problem, and that controls over the sources of pollution need to be tightened. Sewage spills and overflows, breaks in sewer lines or septic systems, and polluted runoff and stormwater. All of these result in sewage, pathogens, toxics and other waste flushing into waterways, and, ultimately, into beach waters.
Rain is often a contributing factor.
Heavy rain can overwhelm sewage systems, forcing rain and raw sewage directly into coastal waters, bypassing the treatment plant. Almost every coastal and Great Lakes state has at least one beach with storm drains on or near the beach. Some states, including New Jersey, California, Florida, Connecticut, Michigan and Massachusetts report having numerous beaches near stormwater outlets. Several reputable studies have confirmed that swimming in polluted waters can result in illness. The most common illness is gastroenteritis.