UCI study offers blueprint for pinpointing sources of beach water pollution

Innovative tests trigger clean up efforts at popular California beach

A UC Irvine-led study has proved instrumental for significantly improving the quality of beach water at a popular California tourist destination. The same study also provides the blueprint for assisting similar beachside communities with an innovative approach for pinpointing the causes of water pollution.

The research was headed by UCI environmental engineer Stanley Grant and USC microbiologist Jed Fuhrman, working with Alexandria Boehm of Stanford University and Robert Mrše of UCI. Their results will be posted Jan. 9, 2003, on the Research ASAP site of Environmental Science & Technology.

The study reveals that it’s possible to identify and track the specific sources of water pollution by combining bacteria sampling with genetic testing. The research team used this technique while studying the causes of beach pollution in Avalon, Catalina Island—a popular tourist destination for swimming and recreational boating. By combining these methods, the researchers found that decaying sewage pipes in the downtown area adjacent to Avalon Bay had been leaking human waste into the shoreline water.

As a result of this research, Avalon officials sliplined the city’s sewer lines to seal the leaks and are currently investigating connecting pipes from private businesses and homes for further leakage. Their work has already decreased bacteria levels along the shoreline by more than 50 percent, and beach closures declined from 31 in 2001 to 15 in 2002.

This approach provides a new method for coastal agencies to comply with tougher beach water quality laws. Currently, beaches are tested for fecal indicator bacteria using methods that only provide general information on potential sources for pollution. High bacteria content can lead to beach closures.

“Right now, beach communities are faced with bacterial pollution without knowing their sources,” said Grant, who has conducted numerous fecal indicator bacteria tests on Southern California beaches. “But the combination of indicator sampling and genetic testing has the potential to make a real difference in efforts to clean up polluted beaches.”

Study funding came from the state’s Clean Beaches Initiative project, which provided for Proposition 13 grants to be made available to fund 38 projects. The initiative’s major goal is to reduce health risks and increase the public’s access to clean beaches.