Drinking water quality · 2026
· Verified
What's in Ontario Municipal Utilities Company, CA tap water
58 contaminants were measured in the Ontario Municipal Utilities Company, CA water system's 2026 annual report. Each is shown below against its federal limit.
- Reporting year
- 2026
- Contaminants measured
- 58
- Over federal limit
- 0
- Approaching the limit
- 0
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
2 PFAS compounds above EPA limits in Ontario Municipal Utilities Company, CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFOA (Perfluorooctanoic acid)
● Over EPA limit (7.5×)2.2× the national p90 (13.649999999999999 ng/L across detecting U.S. systems)
PFOS (Perfluorooctane sulfonic acid)
● Over EPA limit (1.3×)below national p90 (19.900000000000006 ng/L across detecting U.S. systems)
PFHxS (Perfluorohexane sulfonic acid)
● Below limitbelow national p90 (12.049999999999997 ng/L across detecting U.S. systems)
PFPeA
● Detected (no federal limit)below national p90 (15.95999999999999 ng/L across detecting U.S. systems)
PFHxA
● Detected (no federal limit)near national p90 (12.190000000000003 ng/L across detecting U.S. systems)
PFBA
● Detected (no federal limit)below national p90 (18 ng/L across detecting U.S. systems)
Where your water comes from · EPA SDWIS
Ontario Municipal Utilities Company, CA's drinking water comes from ground water, drawn from 18 sources.
Source
- WELL · 14
- WELL NO. · 3
- WELL 41 - RAW
Treatment
- WELL 43 - TREATED (CL2)
- WELL 37 AND 39 IX FINISHED BLEND EFF
- WELLS 37 AND 39 IX COMBINED VESSEL EFF
- + 15 more
Distribution
Also buys water from CHINO BASIN DESALTER AUTH. - DESALTER 2, JURUPA COMMUNITY SD, and 3 more.
Historical readings · EPA Six-Year Review (2012–2019)
3 contaminants historically over EPA limits in Ontario Municipal Utilities Company, CA
Every U.S. public water system reports compliance-monitoring data to EPA. The Six-Year Review releases the 2012–2019 window as a single dataset — here's what your system reported, year by year. Values shown are the highest detection per analyte per year, compared to the federal MCL.
| Contaminant | Worst detection | EPA limit | Years (2012–2019) |
|---|---|---|---|
NITRITE worst: 2013 | 4.9 mg/L 4.9× | 1 mg/L | '12'13 |
NITRATE worst: 2017 | 14 mg/L 1.4× | 10 mg/L | '12'13'14'15'16'17'18'19 |
NITRATE NITRITE worst: 2017 | 12 mg/L 1.2× | 10 mg/L | '17 |
TTHM worst: 2019 | 0.077 mg/L 96% | 0.08 mg/L | '12'13'14'15'16'17'18'19 |
DBCP worst: 2012 | 0.00016 mg/L 80% below national p90 | 0.0002 mg/L | '12'13'14'15'16'17'18'19 |
HAA5 worst: 2015 | 0.043 mg/L within | 0.06 mg/L | '12'13'14'15'16'17'18'19 |
EDB worst: 2018 | 0.000021 mg/L within | 0.00005 mg/L | '18 |
ARSENIC worst: 2013 | 0.0024 mg/L within below national p90 | 0.01 mg/L | '13'17 |
FLUORIDE worst: 2012 | 0.5 mg/L within | 4 mg/L | '12'13'14'15'17 |
CHROMIUM worst: 2013 | 0.0088 mg/L within near national p90 | 0.1 mg/L | '12'13'14'15'17 |
BARIUM worst: 2013 | 0.14 mg/L within near national p90 | 2 mg/L | '13'14'15'17'19 |
DBAA worst: 2012 | 0.0059 mg/L | — | '12'13'14'15'16'17'18'19 |
DCAA worst: 2012 | 0.0041 mg/L | — | '12'13'14'15'16'17'18'19 |
MBAA worst: 2012 | 0.0018 mg/L | — | '12'13'14'15'16'18'19 |
MCAA worst: 2012 | 0.004 mg/L | — | '12'14'15'17'19 |
TCAA worst: 2012 | 0.0031 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMODICHLOROMETHANE worst: 2012 | 0.023 mg/L | — | '12'13'14'15'16'17'18'19 |
BROMOFORM worst: 2012 | 0.013 mg/L | — | '12'13'14'15'16'17'18'19 |
CHLOROFORM worst: 2012 | 0.014 mg/L | — | '12'13'14'15'16'17'18'19 |
DIBROMOCHLOROMETHANE worst: 2012 | 0.025 mg/L | — | '12'13'14'15'16'17'18'19 |
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| PerchlorateA chemical used in rocket fuel and fireworks that can also form during disinfection. | 2.6999999999999997 UG/LAverageSource water | 6 UG/LMCL | Within the limit |
Other
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Tce | 0.98 UG/LAverageSource water | 5 UG/LMCL | Within the limit |
| Carbon Tetrachloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Chlorobenzene | Not detected UG/LHighest single sampleSource water | 70 UG/LMCL | None detected |
| Cis Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Dichloroethane 12 | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
| Dichloroethylene 11 | Not detected UG/LHighest single sampleSource water | 6 UG/LMCL | None detected |
| Dichloropropane 12 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| O Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 600 UG/LMCL | None detected |
| P Dichlorobenzene | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Pce | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Styrene | Not detected UG/LHighest single sampleSource water | 100 UG/LMCL | None detected |
| Trans Dichloroethylene 12 | Not detected UG/LHighest single sampleSource water | 10 UG/LMCL | None detected |
| Trichlorobenzene 124 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Trichloroethane 111 | Not detected UG/LHighest single sampleSource water | 200 UG/LMCL | None detected |
| Trichloroethane 112 | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Vinyl Chloride | Not detected UG/LHighest single sampleSource water | 0.5 UG/LMCL | None detected |
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Combined RadiumCombined radium-226 and radium-228 — naturally occurring radioactive elements. | 0.11841666666666667 PCI/LAverageSource water | 5 PCI/LMCL | Within the limit |
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA)ADONA, a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS)4:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS)6:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS)8:2 fluorotelomer sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Hexafluoropropylene oxide dimer acidHFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA)Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA)Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoro(2-ethoxyethane)sulfonic acid (PFEESA)Perfluoro(2-ethoxyethane)sulfonic acid, a PFAS-related compound. | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorodecanoic acid (PFDA)Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorododecanoic acid (PFDoA)Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroheptanesulfonic acid (PFHpS)Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluorononanoic acidPerfluorononanoic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoropentanesulfonic acid (PFPeS)Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroundecanoic acid (PFUnA)Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' | Not detected NG/LHighest single sampleSource water | None set | None detected |
| Perfluoroheptanoic acidPerfluoroheptanoic acid, a PFAS 'forever chemical.' | 1.2833333333333334 NG/LAverageSource water | None set | Detected — no federal limit |
VOCs & pesticides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Benzene | Not detected UG/LHighest single sampleSource water | 1 UG/LMCL | None detected |
| ChloroethaneA volatile organic compound used in some industrial processes. | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Chloromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dichlorodifluoromethane | Not detected UG/LHighest single sampleSource water | None set | None detected |
| Dichloromethane | Not detected UG/LHighest single sampleSource water | 5 UG/LMCL | None detected |
| Ethylbenzene | Not detected UG/LHighest single sampleSource water | 300 UG/LMCL | None detected |
| Toluene | Not detected UG/LHighest single sampleSource water | 150 UG/LMCL | None detected |
| XylenesA group of industrial solvents found in gasoline and paint. | Not detected UG/LHighest single sampleSource water | 1750 UG/LMCL | None detected |
People also ask about Ontario Municipal Utilities Company, CA's water
+Is Ontario Municipal Utilities Company, CA tap water safe to drink in 2026?
Every one of the 58 contaminants measured in Ontario Municipal Utilities Company, CA's 2026 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Ontario Municipal Utilities Company, CA tap water?
58 contaminants were measured in Ontario Municipal Utilities Company, CA's 2026 Consumer Confidence Report, spanning other, pfas ("forever chemicals"), and vocs & pesticides. 26 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Where does the data on this page come from?
Every value is transcribed from Ontario Municipal Utilities Company, CA's 2026 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Ontario Municipal Utilities Company, CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2026 report; a new report will replace it once the utility publishes its next annual update.