US Water Score: A
| Contaminant | Detected Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| Lead |
1500.0
|
15 ppb | 1 ppb | |
| Copper |
112000.0
|
1300 ppb | 300 ppb |
UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.
| Compound | Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| PFOA | 7.7 ppt | 4 ppt | 4 ppt | Above comparison value |
| PFBA | 6.2 ppt | No standard | 500 ppt | No federal MCL shown |
| PFOS | 5.8 ppt | 4 ppt | 4 ppt | Above comparison value |
| PFBS | 4.4 ppt | 2000 ppt | 100 ppt | Below comparison value |
| PFHxA | 4.3 ppt | No standard | 400 ppt | No federal MCL shown |
| PFPeA | 4.0 ppt | No standard | — | No federal MCL shown |
| PFHxS | 3.6 ppt | 10 ppt | 10 ppt | Below comparison value |
Water Quality Summary
Tap water quality in West Covina, California (91791) receives an overall grade of A (Lower record-based concern) with a score of 86 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 6 points below the California state average of 92. Compared to the national average (75), this area performs significantly better. The area is served by 14 water systems providing water to approximately 168,843 people, using surface water and groundwater sources. Notably, 2 PFAS compounds exceed the EPA final MCL value used for comparison — a significant concern given the persistent nature of these chemicals. Over the past 5 years, water systems here have accumulated 61 violations, including 6 health-based violations.
A score of 86/100 means public water-system records for West Covina, CA show relatively few concerns in the US Water Score model. This is an internal score, not an EPA safety rating, and it does not guarantee conditions at any specific tap.
Health Information
Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.
Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.
Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.
If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.
Copper can leach into water from copper plumbing, especially in newer homes or when water is acidic.
Short-term exposure above 1,300 ppb can cause gastrointestinal distress. Long-term exposure may cause liver or kidney damage. People with Wilson's disease are especially vulnerable.
Copper pipes, fittings, and faucets are the most common source. Corrosive (low-pH) water accelerates copper leaching.
If copper levels are elevated, flush pipes by running water for 15–30 seconds before use. Reverse osmosis and distillation systems effectively remove copper.
Common Questions
Based on public water-system records, West Covina, California receives an internal US Water Score grade of A (Lower record-based concern) with a score of 86/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.
ZIP code 91791 is served by 14 water systems using surface water, groundwater sources, providing water to approximately 168,843 people. Multiple source types mean your water may come from a blend of surface and underground sources.
Lead levels in the public-system record for West Covina, California are 1500.0 ppb, above the currently applicable EPA action level of 15 ppb. EPA's Lead and Copper Rule Improvements lower that action level to 10 ppb when the new requirements take effect. This system-level result does not measure an individual tap; consider a certified lead-removal filter and independent tap testing.
Yes — 7 PFAS compounds were detected in records associated with water serving West Covina, California, and 2 results exceeded the numerical EPA MCL value used for comparison. UCMR5 occurrence results alone are not a regulatory compliance determination. PFAS rules and compliance timelines are evolving; verify current information with the utility and EPA.
Water systems serving West Covina, California have received 61 violations in the last 5 years, including 6 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.
Based on detected contaminants (lead, PFAS, copper), residents in West Covina, California should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.