Modesto, California Water Quality Report
Water quality data for 32 water systems serving 240,146 people.
Water Source
Detected Contaminants
| Contaminant | Detected Level | EPA Limit (MCL) | Health Guideline | % of Limit | Status |
|---|---|---|---|---|---|
| lithium | 21.0 | No federal limit | 10.0 ug/L(EPA/USGS HBSL) | 210% | Above guideline |
| PFBS | 0.004 | No federal limit | 2000.0 ug/L(EPA Health Advisory) | 0% | Below guideline |
| PFHpA | 0.004 | No federal limit | 1000.0 ug/L(EWG) | 0% | Below guideline |
| PFHxA | 0.006 | No federal limit | 1000.0 ug/L(EWG) | 0% | Below guideline |
| PFHxS | 0.009 | 0.010 ug/L | 0.001 ug/L(EWG) | 93% | Near limit |
| PFOA | 0.009 | 0.004 ug/L | 0.090 ug/L(EWG) | 215% | Above limit |
| PFOS | 0.026 | 0.004 ug/L | 0.300 ug/L(EWG) | 650% | Above limit |
| PFPeA | 0.007 | No federal limit | 1000.0 ug/L(EWG) | 0% | Below guideline |
Recommended Water Filters
Based on the contaminants detected in your water supply, these filtration systems are recommended:
Reverse Osmosis (RO)
Reverse osmosis systems remove up to 99% of PFAS compounds. Recommended for homes with detected PFAS.
Up to 99% PFAS removal
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Compliance & Violations
Active Violations (15)
51
Jan 1, 2025
52
Oct 1, 2022
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Resolved Violations (273)
03
Jul 1, 2024 — Sep 30, 2024
03
Apr 1, 2024 — Jun 30, 2024
27
Jan 1, 2024 — Dec 31, 2024
27
Jan 1, 2024 — Dec 31, 2024
3A
Apr 1, 2022 — Apr 30, 2022
+ 268 more resolved violations
Frequently Asked Questions
Is Modesto tap water safe to drink?
Modesto's water has 2 contaminants detected above EPA limits. While the water is treated, residents may want to consider additional filtration.
What contaminants are in Modesto tap water?
8 contaminants have been detected in Modesto's water supply across 32 water systems. See the full contaminant table above for details.
How can I improve my water quality in Modesto?
Install a water filter rated for the specific contaminants found in Modesto's water. See our filter recommendations above. You can also request your utility's Consumer Confidence Report for the most current test results.
Does Modesto have any water quality violations?
Yes, Modesto currently has 15 active violations. See the violations section above for details.