A San Diego County contamination warning sign. File photo
A San Diego County contamination warning sign. File photo

County health officials urged beachgoers Monday to avoid contact with the ocean water due to weekend rain that likely carried bacteria-laden runoff into the ocean via storm drains.

According to the county Department of Environmental Health, coastal waters — including Mission Bay and San Diego Bay — should be avoided for 72 hours after rain.

Swimmers, surfers and other beachgoers were warned that levels of bacteria can rise significantly, especially near outlets that discharge urban runoff into the sea, such as storm drains, creeks and rivers. The runoff may contain large amounts of bacteria from a variety of sources such as animal waste, soil and decomposing vegetation, according to the department.

How long the heightened bacteria levels stick around depends on the intensity of the storm, the volume of runoff and ocean conditions, according to the county.

The rain also prompted authorities to ban swimming at Tijuana Slough National Wildlife Refuge and Border Field State Park. The downpours sent sewage- fouled runoff from the Tijuana River into the surf, according to the county Department of Environmental Health.

Signs warning of contamination hazards will stand between Seacoast Drive and the border until follow-up testing determines the areas are safe for recreational use, county officials said.

—City News Service