Along the Bay's 50-mile shoreline are 22 public beaches and a 22-mile bike path. Where does most of the action take place_ Of all the beaches in Los Angeles County, the beach at Santa Monica is the busiest.

Do Bay Waters Pose Health Risks_

One thing is clear: these reports of illness from swimming in the Bay have contributed to the public's concern about utilizing this most accessible recreational resource. Beach closures due to sewage spills and warnings of contaminated storm drain runoff have heightened our anxiety. Indeed, the Bay has developed a reputation for severe pollution -- an undeservedly extreme characterization of the Bay's pollution problems -- largely because of the continuing perception that swimming in the Bay is hazardous. A 1992 Santa Monica Bay Restoration Project (SMBRP) survey of 500 Los Angeles County adults showed that 41 percent of the public does not visit the Bay because of its concern about water pollution; many respondents claimed, "I might get sick if I swim in the water."

The SMBRP Epidemiology Study

As part of the epi-study, water samples were collected for analysis at various places along the shoreline. In addition, some 13,000 beachgoers were interviewed to obtain information on their beach activities, including their swimming locations and the length of time they spent in the water. The respondents were contacted by telephone 9-14 days after the initial beach interviews so that follow-up information could be obtained about their health.

Pathogens Found in Bay Storm Drains

This was a disturbing and curious finding, inasmuch as enteric viruses are associated with human excrement. Why would pathogens be present in the storm drain system, given that it is completely separate from the sewer system_ Possible sources include illegal sewer connections to the storm drain, leaking sewer lines, malfunctioning septic tanks, and inadequate waste disposal by recreational vehicles, campers or transients.

Several approaches to address pathogen contamination have been implemented while others are being investigated. One obvious and needed approach is to prevent pathogens and pathogen-contaminated runoff from entering the storm drain system in the first place.

Alternatively, pathogens in runoff can be diverted away from nearshore areas, as is the case at the Pico-Kenter storm drain, where the cities of Los Angeles and Santa Monica in 1992 agreed to begin treating the drain's dry-weather flow at the Hyperion Treatment Plant.

A third, ongoing approach is to minimize public exposure to pathogens with warnings and advisories. SMBRP has been instrumental in placing updated warning signs near storm drain outlets and advising beachgoers 1) not to swim within 100 yards of flowing storm drains; and 2) not to swim in the Bay during and for up to three days after a storm.

As long as swimmers abide by these warnings, the Bay's waters should be considered safe to swim in, and not a health risk from pathogens. Potential health risks associated with exposure to chemical contaminants are generally difficult to establish and are considered by public health officials to be relatively low. Obviously, this risk would be greater if a hazardous substance spill occurred.