June 14, 2026
Modesto, CA Water Quality Report 2026
Unlock the full breakdown — detected levels vs. legal limits, plus what removes each one.
Full contaminant breakdown
EPA Six-Year Review compliance monitoring, 2012–2019 — the most recent national compliance dataset EPA has published. See the sections above for more recent violation and PFAS records.
| Contaminant | Avg. detected | Highest sample | Federal limit | Avg. vs. limit |
|---|---|---|---|---|
| Trichloroethylene (TCE)EPA health goal: zero | 6.85 ppb | 54 ppb | 5 ppb | 137% — above |
| Tetrachloroethylene (PCE)EPA health goal: zero | 6.5 ppb | 22 ppb | 5 ppb | 130% — above |
| DBCPEPA health goal: zero | 0.135 ppb | 0.7 ppb | 0.2 ppb | 67% |
| Nitrate | 5210 ppb | 21000 ppb | 10000 ppb | 52% |
| Nitrate + nitrite | 5230 ppb | 16000 ppb | 10000 ppb | 52% |
| Total trihalomethanes (TTHMs) | 38.1 ppb | 98.2 ppb | 80 ppb | 48% |
| UraniumEPA health goal: zero | 13.2 ppb | 71.5 ppb | 30 ppb | 44% |
| Haloacetic acids (HAA5) | 25.8 ppb | 61.1 ppb | 60 ppb | 43% |
| ArsenicEPA health goal: zero | 3.46 ppb | 12 ppb | 10 ppb | 35% |
| Radium (combined)EPA health goal: zero | 1.12 pCi/L | 1.19 pCi/L | 5 pCi/L | 22% |
| Selenium | 5.53 ppb | 6.2 ppb | 50 ppb | 11% |
| Barium | 162 ppb | 310 ppb | 2000 ppb | 8% |
| 1,1-Dichloroethylene | 0.43 ppb | 0.99 ppb | 7 ppb | 6% |
| Chromium (total) | 6.4 ppb | 6.4 ppb | 100 ppb | 6% |
| Fluoride | 154 ppb | 1200 ppb | 4000 ppb | 4% |
| Nitrite | 0.0425 ppb | 0.95 ppb | 1000 ppb | <1% |
Also tested, no detections: 1,1,1-Trichloroethane, 1,1,2-Trichloroethane, 1,2,4-Trichlorobenzene, 1,2-Dichloroethane, 1,2-Dichloropropane, 2,4,5-TP (Silvex), 2,4-D, Alachlor, Antimony, Asbestos, Atrazine, Benzene, Benzo(a)pyrene, Beryllium, Cadmium, Carbofuran, Carbon tetrachloride, Chlordane, Chlorite, Chlorobenzene, Copper, Cyanide, DEHA (adipate), DEHP (phthalate), Dalapon, Dichloromethane, Dinoseb, Dioxin (2,3,7,8-TCDD), Diquat, Endothall, Endrin, Ethylbenzene, Ethylene dibromide (EDB), Glyphosate, Heptachlor, Heptachlor epoxide, Hexachlorobenzene, Hexachlorocyclopentadiene, Lead, Lindane, Mercury (inorganic), Methoxychlor, Oxamyl, PCBs, Pentachlorophenol, Picloram, Simazine, Styrene, Thallium, Toluene, Toxaphene, Vinyl chloride, Xylenes (total), cis-1,2-Dichloroethylene, o-Dichlorobenzene, p-Dichlorobenzene, trans-1,2-Dichloroethylene.
Reverse osmosis (drinking water)
The treatment category most often matched to dissolved contaminants like lead, arsenic, nitrate, fluoride, and radiological contaminants detected in this system.
Shop reverse osmosis →Whole-house carbon filtration
The treatment category most often matched to disinfection byproducts (TTHMs, haloacetic acids), chlorine taste and odor, and organic compounds detected in this system.
Shop whole-house systems →Source: U.S. EPA Six-Year Review 4 compliance monitoring data (2012–2019), the most recent nationwide compliance dataset EPA has released, reported at the water-system level. A detection is not a violation. “Avg. vs. limit” compares the average of laboratory detections to the federal MCL or action level; individual faucets can differ — household plumbing affects lead and copper, and a state-certified laboratory test of your own tap is the only way to confirm levels in your home. Treatment categories are general matches, not a certification claim for a specific product and contaminant.
Water Utility: City of Modesto,
Population Served: 218,771 residents
Data Sources: EPA SDWIS + EPA UCMR5
Report Year: 2026
Modesto, California drinking water is supplied by City of Modesto,. All US public water systems must test drinking water and report results to the EPA under the Safe Drinking Water Act. This report summarizes health-based violations and PFAS detections recorded in federal databases to help you make informed decisions about home water filtration.
EPA Health-Based Violation History
The following contaminants exceeded EPA maximum contaminant levels (MCLs) at this utility since 2010:
| Contaminant | Violation Years | Filter Solution |
|---|---|---|
| Nitrate | 2013 | Under Sink Filters |
Source: EPA Safe Drinking Water Information System (SDWIS), updated quarterly. Health-based violations only.
PFAS "Forever Chemical" Detections
PFAS compounds were detected in this water system during EPA's Fifth Unregulated Contaminant Monitoring Rule (UCMR5) testing program (2023-2025). EPA has set maximum contaminant levels of 4 parts per trillion (ppt) for PFOA and PFOS individually.
| PFAS Compound | Level Detected | Solution |
|---|---|---|
| PFOS | 0.0040 ug/L | PFAS Filters |
| PFHxS | 0.0031 ug/L | PFAS Filters |
| PFOA | 0.0055 ug/L | PFAS Filters |
| PFHxA | 0.0030 ug/L | PFAS Filters |
| PFPeA | 0.0038 ug/L | PFAS Filters |
| PFHpA | 0.0036 ug/L | PFAS Filters |
| PFBS | 0.0034 ug/L | PFAS Filters |
Source: EPA UCMR5 occurrence data. Levels in micrograms per liter (ug/L = parts per billion). 1 ug/L = 1,000 ppt.
Should You Filter Your Modesto Water?
Even utilities with no EPA violations may have contaminants present below legal limits but above health guidelines. The EPA sets maximum contaminant levels based on what is feasible and affordable to treat at scale -- not necessarily what carries zero health risk. Many independent health organizations recommend filtration for households with children, pregnant women, or immunocompromised individuals regardless of utility compliance status.
Protect Your Modesto Home Water
PureWaterGuys.com carries filtration systems certified to reduce PFAS compounds like PFOA and PFOS. We ship to all California addresses with free expert guidance on the right system.
Shop PFAS Water Filters →Take the Water QuizFrequently Asked Questions
Is Modesto tap water safe to drink?
City of Modesto, is required to meet EPA federal drinking water standards. However, meeting legal standards is not the same as being contaminant-free. Trace levels of disinfection byproducts, PFAS compounds, and other regulated contaminants are common in US municipal water systems.
Does Modesto water have PFAS?
PFAS compounds were detected in this utility's water during EPA UCMR5 monitoring. A certified PFAS filter -- such as reverse osmosis or activated carbon block -- can significantly reduce these compounds at your tap.
What water filter works best for Modesto?
A whole-house carbon block filter removes chlorine, chloramines, and many VOCs. For PFAS, arsenic, and nitrates, a reverse osmosis under-sink system provides the highest reduction rates. Take our free 2-minute quiz to find the right system for your home and budget.
Data sourced from EPA SDWIS and UCMR5 federal databases. PureWaterGuys.com is not affiliated with any municipal water utility. Contact your utility's annual Consumer Confidence Report (CCR) for complete local data.