WaterQ
California State Report All States
Official Status: March 2026

Is Rancho Cucuamonga tap water safe to drink?

✓ Generally Safe
A

Mostly yes — Rancho Cucuamonga scores 92/100.

Safety Score
92
out of 100

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Rancho Cucuamonga

California

View California state report Data updated: Mar 2026

Is Rancho Cucuamonga tap water safe to drink?

Mostly yes — Rancho Cucuamonga scores 92/100. This report aggregates EPA drinking water data across 1 local system in Rancho Cucuamonga. We found 5 total violations (5 unresolved).

🛡️ Home Water Treatment Needs

Should you invest in filtration or softening for your home in Rancho Cucuamonga?

Requirement Status
Optional
🟢
💡

Expert Advice

Your water quality is excellent. Standard filtration is optional but can further enhance taste.

Buying a Filter?

Wondering if Rancho Cucuamonga tap water needs filtering? We break it down.

Baby Formula Safety

Mixing baby formula with Rancho Cucuamonga tap water? Read this first.

Homebuyer's Perspective

If you're house-hunting in Rancho Cucuamonga, water quality belongs on your due-diligence checklist alongside schools and crime data. The high safety score (92/100) suggests lower risk for plumbing corrosion and appliance scaling.

Property Impact: Positive / Stable

Health & Family Safety

Residents should monitor Lead (90th percentile) levels. Pregnant women and families with young children should consult the specific EPA health goals listed below.

View Health Risk Glossary →

Compliance Record for Rancho Cucuamonga

5
Violations (5yr)
5
Unresolved
1
Contaminants Tracked
0
Exceeding EPA Limit

Based on EPA SDWIS violation records and contaminant test results for all water systems serving Rancho Cucuamonga.

Frequently Asked Questions

Is Rancho Cucuamonga tap water safe to drink?

Mostly yes — Rancho Cucuamonga scores 92/100.

How many water systems serve Rancho Cucuamonga?

Rancho Cucuamonga is served by 1 public water system in our latest EPA-backed dataset.

How can I check water quality for my exact address in Rancho Cucuamonga?

Use the WaterQ search tool to look up your ZIP code and view nearby systems, contaminant levels, and recent violations for Rancho Cucuamonga.

What is the water quality score for Rancho Cucuamonga?

The water quality score for Rancho Cucuamonga is 92 out of 100, based on EPA contaminant data, violation history, and testing results across the 1 system serving the city.

What are the top contaminants in Rancho Cucuamonga?

The top contaminants detected in Rancho Cucuamonga include Lead (90th percentile). View detailed information on our contaminants page.

Water Quality Score
92/100
Grade
A
Water Systems
1
Population
211,069

Rancho Cucuamonga Water Quality Summary

Rancho Cucuamonga, CA receives a water quality score of 92/100 (Grade A) based on EPA Safe Drinking Water Information System (SDWIS) compliance data for 1 public water system serving the area.

Rancho Cucuamonga's water quality is above the national average, with strong compliance records and low contaminant levels. Residents generally receive clean, safe tap water that meets EPA standards.

Rancho Cucuamonga's score of 92 is 3 points above the California state average of 89, and above the nationwide average of roughly 78/100 across all U.S. states.

Water quality data is sourced from the U.S. EPA SDWIS database and updated quarterly. Learn about our scoring methodology → Read our California water quality rankings report →

Key Contaminants

Lead (90th percentile)
0.002 / 0.015 mg/L
0 mg/L MCL: 0.015 mg/L

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Water Systems Serving Rancho Cucuamonga (1)

Related

Compare Rancho Cucuamonga water quality: View all states · Contaminant library · How we score water quality