Water Quality: Paso Robles, CA
9 water systems • 35,803 people served
Multiple Health ViolationsWater Quality Summary
Paso Robles is served by 9 public water systems with a combined service population of 35,803 people, and has 130 EPA Safe Drinking Water Act violations on record. Critically, 105 of those are health-based violations, meaning one or more contaminants were detected above EPA-established safe levels — a serious public health concern. Paso Robles's violation count is 171% above the national average for California. Contaminants associated with violations include Arsenic, Barium, Lead, Stage 2 DBP, TTHM.
Contaminants Found
Long-term exposure increases risk of skin, bladder, and lung cancers, as well as cardiovascular and neurological effects.
Common source: Natural rock deposits, agricultural pesticides, industrial waste
EPA limit: 0.010 mg/L (10 ppb)
Increases blood pressure and causes cardiovascular effects with long-term exposure.
Common source: Natural rock deposits, oil drilling operations, coal power plant waste
EPA limit: 2 mg/L
Causes neurological damage, developmental delays in children, and kidney damage in adults even at low exposure levels.
Common source: Old plumbing pipes, lead solder, brass fixtures
EPA limit: Action Level: 0.015 mg/L (15 ppb)
Trihalomethanes and haloacetic acids that increase cancer risk and may cause adverse reproductive outcomes.
Common source: Chlorine disinfection reacting with natural organic matter in source water
EPA limit: TTHM: 0.080 mg/L; HAA5: 0.060 mg/L
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 Paso Robles
| System Name | PWSID | Source | Population | Violations |
|---|---|---|---|---|
| CITY OF PASO ROBLES WATER DIVISION | CA4010007 | Surface Water | 31,176 | 1 |
| HERITAGE RANCH CSD | CA4010012 | Surface Water | 2,956 | 57 |
| CROWN POINTE ESTATES AT MALIBU, LLC | CA5610006 | Groundwater | 690 | 1 |
| WALNUT HILLS MUTUAL WATER CO | CA4000670 | Groundwater | 486 | 0 |
| GREEN RIVER MUTUAL WATER CO. | CA4000554 | Groundwater | 350 | 6 |
| RANCHO SALINAS MBWC | CA4000803 | Groundwater | 50 | 3 |
| ALMIRA WATER ASSOCIATION | CA4000631 | Groundwater | 40 | 46 |
| MUSTANG SPRINGS MUTUAL WATER | CA4000775 | Groundwater | 30 | 10 |
| ADA'S LODGES | CA4000839 | Groundwater | 25 | 6 |
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.