California regulations establish the drinking water monitoring requirements that the Bolinas Community Public Utility District (BCPUD) must follow to ensure that water delivered to customers is safe. The testing schedule is established by the California State Water Resources Control Board’s Division of Drinking Water and varies depending on the type of contaminant, the water source, and previous monitoring results.
For BCPUD, testing generally includes:
- Microbiological Testing (Bacteria): Water is routinely sampled throughout the distribution system each month to test for total coliform bacteria and, when necessary, E. coli. These tests verify that the distribution system remains free of bacterial contamination. If a routine sample is positive for total coliform, follow-up samples are collected immediately as required by regulation.
- Disinfection Monitoring: Operators monitor disinfectant residuals (chlorine) to ensure adequate protection against harmful microorganisms while maintaining levels within regulatory limits. This monitoring is performed regularly as part of daily operations.
- Inorganic Chemicals: Water is periodically tested for naturally occurring and man-made inorganic contaminants such as nitrate, fluoride, arsenic, chromium, and other metals. Most of these analyses are performed on schedules ranging from annually to once every several years, depending on state requirements and previous results.
- Organic Chemicals: The District periodically tests for volatile organic compounds (VOCs), synthetic organic compounds (SOCs), pesticides, herbicides, and industrial chemicals that could affect drinking water quality. Monitoring frequency is determined by regulatory requirements and the vulnerability of the water source.
- Radiological Contaminants: State regulations require periodic monitoring for radioactive contaminants, including gross alpha particles, uranium, and radium. These samples are typically collected on multi-year compliance schedules.
- Lead and Copper: Rather than testing water at the treatment facility, BCPUD collects samples from selected customer taps during required monitoring periods to evaluate the potential for lead or copper to leach from household plumbing.
- Emerging Contaminants: The District also participates in state and federal monitoring programs for emerging contaminants when required. Current examples include PFAS (per- and polyfluoroalkyl substances) and lithium monitoring. These programs help regulators better understand the occurrence of these substances in drinking water supplies.
All drinking water samples are analyzed by California-certified laboratories, and the results are reviewed by the State Water Resources Control Board. If any sample exceeds a drinking water standard, BCPUD is required to investigate the cause, take any necessary corrective actions, and notify customers when required by state and federal regulations.
This information is summarized each year in BCPUD’s Consumer Confidence Report (Annual Water Quality Report), which provides customers with the monitoring results and confirms whether the District’s drinking water met all applicable drinking water standards during the reporting year. Test results for some of the constituents found in BCPUD are available Here.