SAN DIEGO Thanks to the drought, state and county beaches have been safer over the past year, with less pollution from motor oil, trash and animal waste flowing to the ocean, according to an annual report.
“San Diego in general has really good water quality, especially in dry weather,” said Leslie Griffin, a data analyst at Heal the Bay, the organization that authored the Beach Report Card released Wednesday.
But while safer beaches may seem like a silver lining to critically low levels of rainfall, Heal the Bay’s report and other experts caution that the drought likely hides underlying problems that cause pollution at beaches.
“When the rains come back, then we will start to see a return to baseline conditions that we’ve seen over the years,” said Travis Pritchard, the program director at San Diego Coastkeeper.
Urban runoff is the largest source of pollution at beaches, and the dry spell just means that more contaminants like motor oil, lawn fertilizer and trash have accumulated on land, Pritchard said.
“It’s the water that flows over our streets, sidewalks and lawns and it carries with it all the pollutants that are slowly building up and gathering over time,” he said. “As that goes out to the ocean, that’s where we get the real unsafe, dangerous swimming.”
Tests show unusually high bacteria levels in rivers and Pritchard said he expects levels to spike at beaches once it rains.
While the drought might have inflated scores in Heal the Bay’s report, overall San Diego still is in good shape when it comes to health risks at beaches. Locally, 93 percent of the 72 monitoring stations received an A grade during dry weather in the summer and winter, scoring better than the statewide average, and the average for Southern California coastal counties. And when it rains, 75 percent of locations receive an A, also above state and regional scores. Locations were scored from April 2014 to March 2015.
Mission Bay, however, has a few hot spots, the report says. A monitoring point near the visitors center received an F for the period between April and October. It was the only location in the county to receive an F for this time of the year, and it places fifth in the report’s list of “Top Ten Beach Bummers.” It was the only location in the county on the list since 2013.
Locations in Mission Bay north of Leisure Lagoon and Vacation Isle received C grades. They were the second-worst scores in the county.
Mission Bay and other enclosed bodies often have high bacterial levels because water doesn’t circulate as quickly as in open waterways like oceans, Griffin said.
“The grades tend to struggle there a little more because there’s less water circulation,” she said.
Heal the Bay published its first Beach Report Card in 1991 to give beachgoers a better understanding of the health risks they faced at the coast.
It scores more than 600 locations along the West Coast and assigns them A to F scores based on the health risks posed by water quality. Grades are based on fecal bacteria pollution concentrations in the surf zone, and the higher bacterial concentration, the greater the health risk.