Ontario, CA Water Quality Report
Is Ontario tap water safe? See PFAS and lead contamination levels for Ontario, California. Compare to EPA limits and get filter recommendations.
Quick Answers
Is Ontario, CA tap water safe to drink? Ontario, CA tap water meets most federal EPA limits, but PFAS compounds have been detected at an average of 0.01 ppt across 7 compounds. A certified pitcher filter or reverse osmosis system is recommended for sensitive populations.
What contaminants are in Ontario, CA water? Top PFAS compounds detected in Ontario water: PFOA (0.03 ppt), PFOS (0.01 ppt), PFHxS (0.01 ppt). See the full table for all monitored contaminants and comparison to EPA limits.
What filter should I use in Ontario, CA? Match the filter to what's in California water: reverse osmosis handles PFAS, lead, and arsenic together (90%+ removal); NSF-53 certified pitchers like Clearly Filtered or ZeroWater cover taps you drink from. A standard Brita pitcher will not remove PFAS.
Ontario, CA Water Quality Summary
EPA testing has detected PFAS "forever chemicals" in Ontario, CA drinking water. Recent monitoring found a peak level of 0.03 ppt across 3 water systems, representing an average of 0.01 ppt across 7 detected compounds.
Contamination Level: LOW – Low contamination – PFAS detected but at lower levels; monitoring continues.
Top Detected Compounds
- PFOA: 0.03 ppt
- PFOS: 0.01 ppt
- PFHxS: 0.01 ppt
- PFPeA: 0.01 ppt
- PFHxA: 0.01 ppt
Lead in Ontario, CA Water
EPA Lead and Copper Rule testing has recorded 22 lead samples for Ontario water systems, with a 90th-percentile high of 0.005 mg/L (within the EPA 0.015 mg/L action level). There is no safe level of lead for children; if your home was built before 1986, a certified NSF/ANSI 53 lead-removal filter is recommended.
EPA Violations in Ontario, CA
Ontario public water systems have 34 health-based EPA Safe Drinking Water Act violations on record, including Haloacetic Acids, Nitrate, Arsenic, Total Trihalomethanes, Gross Alpha. Health-based violations mean a contaminant exceeded its federal limit or required treatment was not applied.
About the Data
These figures come from the EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR5) testing program, 2023-2025. UCMR5 is the most comprehensive national drinking water survey in US history, covering 66,000+ public water systems. Population of Ontario, CA: approximately 175,265.
ZIP Codes Served
What Ontario, California Residents Should Do
- Enter your exact ZIP code at knowyourexposure.com for address-level data
- If anyone in your household is pregnant or under 5, prioritize a certified PFAS filter now and consider a home test kit
- For long-term protection, an NSF/ANSI 58 reverse osmosis system removes 94-99% of PFAS
- Read the Consumer Confidence Report (CCR) your California utility publishes each year