Pacifica extends water‑quality monitoring as scientists report widespread bacteria in San Pedro Creek and at Linda Mar

The Pacifica City Council voted unanimously Aug. 26 to extend the city’s agreement with the San Mateo County Resource Conservation District (RCD) for ongoing water‑quality monitoring of San Pedro Creek and Linda Mar (Lindamar) Beach.

The council approved the fifth amendment to the interagency agreement — continuing RCD sampling and microbial source‑tracking work through 2026–2028 — as part of its consent calendar. The monitoring feeds the San Pedro Creek and Pacifica State Beach Total Maximum Daily Load (TMDL) work required under Clean Water Act section 303(d), city and county staff said.

The extension comes after a staff and partner presentation that summarized multi‑year sampling and genetic source‑tracking results. RCD water quality specialist Clifton Herman said the program uses two main tools — bacteria concentration measurement and microbial source tracking (MST) — to determine whether bacteria in the creek are associated with humans, dogs or horses and where in the watershed they appear. “We did see high concentrations at that 1 location,” Herman said, pointing to a storm drain at Seville and Oviedo Court (the site labeled “COSD” in RCD figures) as a recurring hotspot of human‑associated markers.

Why it matters: elevated bacteria are an indicator of possible pathogens that can make people sick, so the monitoring helps target where remediation or outreach can reduce public‑health risk. The RCD and the Lindamar Water Quality…