No open EPA violations as of 2026-10-15.
EPA record checked 2026-10-06
From EPA's record for CA3610034. PurityMap is independent of Ontario Municipal Utilities Company.
Every community water system publishes one each year.
Read the report ↗As listed in EPA's records. Your water bill names your supplier.
A ZIP code is a postal area, not a water service area. Your water bill names your supplier.
Are you this utility? Correct this listing →
32 results are on record. These 5 come first: results above a listed reference, then those closest to a legal limit.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Perfluorooctanoic acid (PFOA) | 30 ng/L | 4.0 ng/L federal MCL (2024) | Above EPA's 2024 limit (one sample) | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorooctanesulfonic acid (PFOS) | 5.2 ng/L | 4.0 ng/L federal MCL (2024) | Above EPA's 2024 limit (one sample) | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Water hardness | 7.8 gpg | Aesthetic, no federal health limit | Above a secondary/aesthetic reference | 2025 | Ontario Municipal Utilities Company 2025 Consumer Confidence Report (CCR) |
| Perfluorohexanesulfonic acid (PFHxS) | 4.2 ng/L | 10 ng/L federal MCL (2024) | At or below EPA's 2024 limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Lead (90th percentile) | 0.6 µg/L | 15 µg/L federal action level | Below the listed reference | 2022–2024 monitoring period | Lead & Copper Rule 90th-percentile: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorohexanoic acid (PFHxA) | 7.1 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Within a historical reference; current applicability unverified | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorobutanoic acid (PFBA) | 6.4 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoropentanoic acid (PFPeA) | 6.7 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 1H, 1H, 2H, 2H-perfluorodecane sulfonic acid (8:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 1H, 1H, 2H, 2H-perfluorohexane sulfonic acid (4:2 FTS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 1H, 1H, 2H, 2H-perfluorooctane sulfonic acid (6:2 FTS) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| 9-Chlorohexadecafluoro-3-oxanone-1-sulfonic acid (9Cl-PF3ONS) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Lithium | < 9 µg/L | 10 µg/L EPA health reference level (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2023-02-01 to 2023-11-09 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2023-11-09 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2023-11-09 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorobutanesulfonic acid (PFBS) | < 3 ng/L | 2,000 ng/L EPA health advisory (screening, not a legal limit)Screening level, not a legal limit | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2023-11-09 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2023-11-09 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2023-02-01 to 2024-02-28 | UCMR5 Analytical Results: ONTARIO MUNICIPAL UTILITIES COMPANY (CA3610034) |
0health-based violations in the last 10 years · none open as of 2026-10-15
From EPA SDWIS. A clean violation history means no enforcement action was recorded; it does not cover contaminants without a limit. Meeting a federal limit is a compliance fact, not a health clearance.
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure
Screening: quick check, not lab-grade
Safe Home (EnviroTestKits)
Lead, read as one of three ranges: 0–4, 5–15 or 15+ ppb
Turnaround: 5 minutes
What it can't tell you: It shows a lead range, not an exact level, and tests nothing else unless you pay extra for the optional lab test.
Lab-certified results
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638 · 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Tested your own tap? Read your results →
★ Best choice: Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200), certified for PFOA, PFOS and lead.
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| ★ Best choice | Aquasana Claryum 2-Stage Under-Sink Filter (AQ-5200) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price on Amazon |
| Also good | Aquasana Claryum 3-Stage Max Flow Under-Sink Filter (AQ-6300M) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price at Aquasana |
| Also good | Aquasana Clean Water Machine Countertop Filter (AQ-CWM2) | Certified for PFOA and PFOS (NSF/ANSI 53, WQA) | $$ | Check price at Aquasana |
★ Best choice: HealthShield™, certified for PFOA, PFOS and PFHxS.
| Pick | Product | Certification | Price | Link |
|---|---|---|---|---|
| ★ Best choice | HealthShield™ | Certified for PFOA, PFOS and PFHxS (NSF/ANSI 53, WQA) | $$$$ | Check price at Aquasana |
| $ Budget pick | iSpring WGB32B-PFKS PFAS & Heavy Metals Whole House FilterUse code REFISPRING at checkout: 10% off your first iSpring order. | Brand lab-tested for PFAS, not independently certified for PFOA, PFOS, Perfluorohexanoic acid (PFHxA), PFHxS, Perfluorobutanoic acid (PFBA) and Perfluoropentanoic acid (PFPeA) | $$$ | Check price at iSpring |
Also: lead picks →
PurityMap earns a commission from these links. "Best choice" and "Budget pick" go to certified products first; commission never decides them. As an Amazon Associate, PurityMap earns from qualifying purchases. Affiliate disclosure.
Local help
Call to be connected with a local plumbing provider about lead service lines, repiping or fixture replacement.
One email when a new sampling round is published or a result moves across its reference.
Follow this water →Its official website is ontarioca.gov, its phone number on EPA record is 909-395-2682 and its mailing address is 1425 S. BON VIEW AVE., ONTARIO, CA 91761. These details come from the system's EPA record and a check of its website.
Bills, starting service and stopping service are handled by Ontario Municipal Utilities Company on its official website, ontarioca.gov. PurityMap does not take payments.
EPA's records list Ontario Municipal Utilities Company as serving Ontario, California. Your water bill names your supplier.
PurityMap's record for Ontario Municipal Utilities Company holds results for 29 PFAS substances. 6 were detected, and none is above a federal legal limit. Each result links to its source in the city report.
No open EPA violations as of 2026-10-15: that is what EPA's record shows for Ontario Municipal Utilities Company. The record comes from EPA's SDWIS compliance database.
Ontario Municipal Utilities Company is on EPA record as drawing from surface water.
Start with the hot-or-cold tap check. Where Ontario Municipal Utilities Company reported something related, it's shown below.
Lead at Ontario Municipal Utilities Company: 0.6 µg/L (90th percentile, 2022–2024 monitoring period). Lead has no taste, so a taste neither shows nor rules it out.