By analyzing water quality data and beach warnings posted in the summer of 2001 for Huntington Beach a popular coastal resort reputed to have inspired Jan and Dean's "Surf City" researchers found that the public was incorrectly notified about coastal water quality as much as 41 percent of the time.
Errors were caused by a combination of factors, including infrequent sampling and testing, rapid changes in water quality and a state warning system that only allows water to be determined safe or unsafe.
The research was headed by Stanley Grant, chair of the chemical engineering and materials sciences department at UCI. Results were published in three companion papers this week on the Web site for Environmental Science & Technology, a publication of the American Chemical Society.
"Our existing warning system fails at precisely the moment it's needed most," said Grant. "When water quality is relatively good, the warning system works fine. But when it's not, the warning system is so error prone, you'd do just as well to base your decision to go in the water on the flip of a coin."
As part of a solution, the researchers have proposed that coastal states like California adopt a warning system that provides the public a range of risk, much like the forecasts provided by daily weather reports. "We're all pretty comfortable with interpreting weather reports, in which information is conveyed to the public as a probability for example, there's a 30 percent chance of rain today," Grant said. "Of course, a lot of science goes into the generation of weather forecasts, and water quality forecasts will be no different."