Skip to main content









Donation Heart Ribbon

New Faster Water Quality Test Is Given A Chance In San Diego

San Diego County Supervisors approved a test run for a new DNA-based water testing system on Tuesday.

It could make water monitoring much more accurate.

Photo credit: Urban Adventures

Torrey Pines State Beach in San Diego

San Diego County officials will start testing a DNA-based tool to measure water quality at beaches. That new test could protect public health better than the current system.

Right now, water quality testing is pretty standard in San Diego County. Fill a small beaker with water, add a powdered chemical, put it in a tray and wait.

"The problem with this is because you're culturing out live bacteria. You need them to grow before you can measure. It takes 24 hours. Sometimes up to 48 hours," said San Diego Coastkeeper's Travis Pritchard.

He routinely used the same test county officials use to check for pollution and he agrees that time is a huge issue.

People who monitor San Diego County's ocean water quality want to be able to tell swimmers if the water is dirty now, not whether it was dirty a couple of days ago.

San Diego County supervisors agreed to try out a new federally approved DNA test that works in two to four hours.

"It's good science and it's also good business," said Supervisor Greg Cox.

A faster test means the county will have better information for swimmers and surfers.

"Our goal is to open up the beaches as quickly as we can, once we are able to verify that they're safe for the public to go in," said Cox. "This newer testing will allow us to do that in four hours as opposed to the waiting the 48 hours to get the current lab test results."

The county agreed to spend $59,000 to test the new method. If results are good, the county will work on changing state rules to permit the faster test.

Want more KPBS news?
Find us on Twitter and Facebook, or subscribe to our newsletters.

To view PDF documents, Download Acrobat Reader.