US Water Score: A
| Contaminant | Detected Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| Lead |
0.0
|
15 ppb | 1 ppb | Passed |
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 |
|---|---|---|---|---|
| PFBA | 11.0 ppt | No standard | 500 ppt | No federal MCL shown |
| PFHxS | 7.4 ppt | 10 ppt | 10 ppt | Below comparison value |
| PFOS | 5.6 ppt | 4 ppt | 4 ppt | Above comparison value |
| PFPeA | 3.5 ppt | No standard | — | No federal MCL shown |
| PFHxA | 3.3 ppt | No standard | 400 ppt | No federal MCL shown |
Water Quality Summary
Tap water quality in Montclair, California (91763) receives an overall grade of A (Lower record-based concern) with a score of 89 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is roughly in line with the California state average of 92. Compared to the national average (75), this area performs significantly better. The area is served by Monte Vista Wd, a surface water system providing water to approximately 56,017 people. Notably, 1 PFAS compound exceeds the EPA final MCL value used for comparison — a significant concern given the persistent nature of these chemicals. The area has a clean violation record over the past 5 years — a positive indicator of consistent water quality management.
A score of 89/100 means public water-system records for Montclair, 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.
Common Questions
Based on public water-system records, Montclair, California receives an internal US Water Score grade of A (Lower record-based concern) with a score of 89/100. 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 91763 is served by 1 water system using surface water sources, providing water to approximately 56,017 people. Surface water systems are more susceptible to contamination from agricultural runoff, industrial discharge, and weather events, but typically undergo more extensive treatment including filtration and disinfection.
Lead levels in Montclair, California are 0.0 ppb, which is at or below the health guideline of 1 ppb. This is a positive result, though periodic testing is still recommended.
Yes — 5 PFAS compounds were detected in records associated with water serving Montclair, California, and 1 result 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 Montclair, California have zero violations in the last 5 years. This is a positive indicator of consistent regulatory compliance and water quality management.
Based on detected contaminants (PFAS), residents in Montclair, 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.