Unsafe bacteria levels discovered at the coast, Bay

On the Bay, individuals should avoid water contact at Lakeshore, Erckenbrack and Marlin Park this week, according to environmental health services data for the past week.

Half Moon Bay has been dealing with the harmful impact of stormwater runoffs causing unsafe bacteria levels at its beaches for many years, Harbor District General Manager James Pruett said. Beaches that continue to see the fecal bacteria — including the Pillar Point area and Venice Beach — receive stormwater runoff from a variety of output, Pruett said.

“It’s not the beach that is generating bacteria, not the harbors that are generating bacteria for the coastside,” he said.

A 2021 staff report from the California Water Board evaluated data from the county over the past decade and found that Venice Beach, as well as all of the tested areas around Pillar Point harbor, maintained above-average levels of contaminants.

“The water quality concern for people using the beach is increased risk of illness resulting from exposure to pathogens, which is directly linked to the level of indicator bacteria in the water,” the report read.

Studies have shown that “dog-associated markers” were frequently detected near freshwater creeks, and grease, litter and organic matter continue to play a role. At, and around, the harbor, waste from commercial fishing, structure runoff and fueling facilities can also contribute to the bacteria ecosystem, per the staff report.

Ultimately, however, stormwater runoff is well-documented as the “primary transport mechanism” for fecal bacteria during the wet seasons.

The California Water Board aims to alleviate that bacteria through regular monitoring mechanisms both of the contaminants themselves as well as the sanitary sewer collection systems, the harbor district, and the cities responsible for protecting against excess stormwater runoff.

The Harbor District has worked to contain other potential sources of bacteria, offering a free pump-out service for boat sewage materials and testing, inspecting and repairing all stormwater pipes. Public restrooms are also provided on-site, Pruett said, but bacteria remains.

“When you walk your dog on the coastside, be sure to pick it up,” he said.

Many other beaches on the coast, including Surfer’s Beach, Roosevelt Beach and Dune Beach don’t face impairment, according to the staff report. Harmful bacteria trends upwards during the wet season, and individuals should always stay out of the water three days after a storm event, according to the county.