Water Quality: Redwood City, CA
3 water systems • 93,569 people served
Multiple Health ViolationsWater Quality Summary
Redwood City is served by 3 public water systems with a combined service population of 93,569 people, and has 66 EPA Safe Drinking Water Act violations on record. Critically, 11 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Redwood City's violation count is 37% above the national average for California. Contaminants associated with violations include E. coli, Fecal Coliform, TTHM, Total Haloacetic Acids (HAA5).
Contaminants Found
Causes gastrointestinal illness; certain strains (e.g., O157:H7) can cause severe kidney failure and death.
Common source: Fecal contamination from humans or animals entering the water supply
EPA limit: Zero (no E. coli permitted in drinking water)
Indicates direct fecal contamination; associated with diarrhea, cramps, nausea, and potential severe illness.
Common source: Human and animal fecal waste
EPA limit: Zero tolerance (any positive triggers violations)
Total trihalomethanes are linked to increased risk of bladder cancer and adverse reproductive outcomes.
Common source: Reaction of chlorine disinfectants with naturally occurring organic matter in water
EPA limit: 0.080 mg/L (80 ppb)
Haloacetic acids are associated with increased cancer risk and potential reproductive and developmental effects.
Common source: Reaction of chlorine disinfectants with organic matter in treated water
EPA limit: 0.060 mg/L (60 ppb)
Water Systems Serving Redwood City
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| CITY OF REDWOOD CITY | CA4110022 | Surface Water | 92,819 | 3 |
| COUNTY SERVICE AREA 11 | CA4100582 | Groundwater | 450 | 30 |
| COUNTY SERVICE AREA 7 | CA4100509 | Surface Water | 300 | 33 |
Concerned About Your Water?
A home water filter can remove common contaminants. NSF-certified filters are tested against EPA standards.
Consider a reverse osmosis system for comprehensive filtration or a carbon filter for basic improvement.
Other Cities in California
Data Sources
Drinking water violation data from the EPA Safe Drinking Water Information System (SDWIS). Data includes all recorded violations for active community water systems.