San Diego County has started using new ocean water-quality testing technology intended to produce faster results and earlier warnings when bacteria reach unhealthy levels.

During a rollout of the DNA-based technology last week, county Board of Supervisors Vice Chairwoman Nora Vargas said the county plans to expand its use of the testing technology, known as droplet digital polymerase chain reaction, or ddPCR, to more than 70 miles of shoreline that the county samples and tests to help protect the public.