Excellent Water Quality
| Compound | Level | EPA MCL | Health Guideline | Status |
|---|---|---|---|---|
| PFPeA | 18.0 ppt | No standard | — | Unregulated |
| PFHxA | 17.0 ppt | No standard | 400 ppt | Unregulated |
| PFOA | 7.3 ppt | 4 ppt | 4 ppt | Exceeded |
| PFBA | 5.7 ppt | No standard | 500 ppt | Unregulated |
| PFBS | 4.6 ppt | 2000 ppt | 100 ppt | Below limit |
| PFHpA | 3.5 ppt | No standard | — | Unregulated |
| PFHxS | 3.5 ppt | 10 ppt | 10 ppt | Below limit |
Water Quality Summary
Tap water quality in Rialto, California (92377) receives an overall grade of A (Excellent) with a score of 90 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 9 points above the California state average of 81. Compared to the national average (75), this area performs significantly better. The area is served by 2 water systems providing water to approximately 158,951 people, using surface water sources. Notably, 1 PFAS compound exceeds EPA limits — 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 90/100 means the water supply in Rialto, CA meets or exceeds all EPA standards with minimal issues. Contaminant levels are well within safe limits, and the water system has maintained a strong compliance record. While no water supply is guaranteed perfect at the tap due to household plumbing, this is among the best-scoring areas in the country.
Common Questions
Based on EPA data, tap water in Rialto, California receives a grade of A (Excellent) with a score of 90/100. This indicates the water meets federal standards and has relatively few concerns. However, individual homes may still have localized issues such as lead from old plumbing.
ZIP code 92377 is served by 2 water systems using surface water sources, providing water to approximately 158,951 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.
No lead data is currently available for ZIP code 92377. This may mean lead testing results haven't been reported recently, or the serving water system uses monitoring waivers. You can request a free lead test kit from most water utilities or purchase a certified home testing kit.
Yes — 7 PFAS compounds were detected in water serving Rialto, California, and 1 exceeds EPA maximum contaminant levels. PFAS are persistent chemicals linked to cancer, immune system effects, and developmental issues. A reverse osmosis or activated carbon filter certified for PFAS removal is recommended.
Water systems serving Rialto, 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 Rialto, 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.
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