San Mateo County Tightens Farmworker Housing Water Rules

SAN MATEO COUNTY, CA — San Mateo County will require regular water testing and inspections at farmworker housing sites after an investigation found bacterial contamination in 55% of systems tested.

The Board of Supervisors approved the program Oct. 20, establishing new oversight for 32 water systems serving 49 farmworker housing units in unincorporated San Mateo County. The requirements take effect Nov. 19, according to a county announcement.

Previously, small water systems serving farmworker housing with four or fewer connections generally operated without routine oversight. County officials typically intervened only when reports identified an imminent health hazard.

The county launched a broader investigation into farmworker housing conditions after the January 2023 mass shooting at two Coastside farms that killed seven farmworkers and critically injured another person. The tragedy exposed unsafe living conditions in employer-provided housing.

As part of that investigation, inspectors tested 38 water systems that lacked regular state monitoring and found coliform bacteria, E. coli or both in 21 systems.

County officials said corrective actions were completed at all affected systems, and follow-up testing confirmed the water was safe to drink.

“After the tragedy in January 2023, we made a promise that every farmworker on the Coastside would live in a safe and healthy home,” Supervisor Ray Mueller said in the announcement.

Under the new program, operators must test for bacteria every three months, meet water quality, quantity and pressure standards, and allow regular county inspections.

The county also established a $1,706 annual permit fee per system. Applications submitted by June 30, 2027, qualify for a full subsidy, with financial assistance gradually decreasing in subsequent years.