A
90

Excellent Water Quality

Rialto, CA 92376

San Bernardino County · Population served: 373,616 · Data updated March 2026

Water Systems Serving This Area

🏔
WEST VALLEY WATER DISTRICT
Surface water · Pop. 104,498
PWSID: CA3610004
🏔
RIALTO, CITY OF
Surface water · Pop. 54,453
PWSID: CA3610038
🌊
SAN BERNARDINO CITY
Groundwater · Pop. 214,665
PWSID: CA3610039

PFAS / Forever Chemicals

11 detected 1 above EPA limits
CompoundLevelEPA MCLHealth GuidelineStatus
PFPeA18.0 pptNo standardUnregulated
PFHxA17.0 pptNo standard400 pptUnregulated
PFOA7.3 ppt4 ppt4 pptExceeded
PFBA5.7 pptNo standard500 pptUnregulated
PFBS4.6 ppt2000 ppt100 pptBelow limit
PFBS4.4 ppt2000 ppt100 pptBelow limit
PFHxA4.0 pptNo standard400 pptUnregulated
PFHxS4.0 ppt10 ppt10 pptBelow limit

Water Quality Summary

Understanding Your Water in Rialto

Tap water quality in Rialto, California (92376) 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 3 water systems providing water to approximately 373,616 people, using surface water and groundwater 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.

Your Score 90/100 A
vs State 9 pts above California avg (81)
vs National 15 pts above national avg (75)

What a Grade A Means

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.

Surface water: sourced from rivers, lakes, or reservoirs
Groundwater: drawn from underground aquifers via wells

Common Questions

Frequently Asked 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 92376 is served by 3 water systems using surface water, groundwater sources, providing water to approximately 373,616 people. Multiple source types mean your water may come from a blend of surface and underground sources.

No lead data is currently available for ZIP code 92376. 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 — 11 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.

Explore Nearby

Water Quality in Nearby ZIP Codes