No open health-based violations on EPA record in the last 10 years; latest legal-limit breach in the period starting July 2025.
Serves about 13,000 people (413 connections) with surface water from its own intake, and buys water from Stillwater Utilities Authority.
From EPA's record for OK1020910. PurityMap is independent of Osu Water Plant.
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13 health-based violations in the last 10 years, from EPA's SDWIS compliance database.
| Period | Contaminant | Measured | Legal limit | EPA status |
|---|---|---|---|---|
| Jul–Sep 2025 | Total trihalomethanes (TTHM) | 0.081 mg/L | 0.080 mg/L | Resolved |
| Apr–Jun 2025 | Total trihalomethanes (TTHM) | 0.082 mg/L | 0.080 mg/L | Resolved |
| From March 2023 | Surface Water Treatment Rule | – | – | Resolved |
| Oct–Dec 2019 | Total trihalomethanes (TTHM) | 0.081 mg/L | 0.080 mg/L | Resolved |
| Apr–Jun 2019 | Total trihalomethanes (TTHM) | 0.088 mg/L | 0.080 mg/L | Resolved |
| Period | Contaminant | Measured | Legal limit | EPA status |
|---|---|---|---|---|
| Apr–Jun 2019 | Total trihalomethanes (TTHM) | 0.086 mg/L | 0.080 mg/L | Resolved |
| Apr–Jun 2019 | Total trihalomethanes (TTHM) | 0.088 mg/L | 0.080 mg/L | Resolved |
| Jan–Mar 2019 | Total trihalomethanes (TTHM) | 0.088 mg/L | 0.080 mg/L | Resolved |
| Jan–Mar 2019 | Total trihalomethanes (TTHM) | 0.084 mg/L | 0.080 mg/L | Resolved |
| Jan–Mar 2019 | Total trihalomethanes (TTHM) | 0.084 mg/L | 0.080 mg/L | Resolved |
| Oct–Dec 2018 | Total trihalomethanes (TTHM) | 0.082 mg/L | 0.080 mg/L | Resolved |
| Oct–Dec 2018 | Total trihalomethanes (TTHM) | 0.085 mg/L | 0.080 mg/L | Resolved |
| Jul–Sep 2018 | Total trihalomethanes (TTHM) | 0.082 mg/L | 0.080 mg/L | Resolved |
EPA required this system to test for 30 unregulated and emerging contaminants, from January 2024 to October 2024.
| Contaminant | Result | Limit | Status | Sampled | Source |
|---|---|---|---|---|---|
| Perfluorobutanoic acid (PFBA) | 7.9 ng/L | No federal or state limit; shown for transparency | Detected, no limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Hexafluoropropylene oxide dimer acid (HFPO-DA) (GenX chemicals) | < 5 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | < 5 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | < 6 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Nonafluoro-3,6-dioxaheptanoic acid (NFDHA) | < 20 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoro (2-ethoxyethane) sulfonic acid (PFEESA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| 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 | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorodecanoic acid (PFDA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorododecanoic acid (PFDoA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoroheptanesulfonic acid (PFHpS) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoroheptanoic acid (PFHpA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorohexanesulfonic acid (PFHxS) | < 3 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorohexanoic acid (PFHxA) | < 3 ng/L | 400,000 ng/L Michigan EGLE state MCL (strictest US state) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorononanoic acid (PFNA) | < 4 ng/L | 10 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorooctanesulfonic acid (PFOS) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorooctanoic acid (PFOA) | < 4 ng/L | 4.0 ng/L federal MCL (2024) | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoropentanesulfonic acid (PFPeS) | < 4 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoropentanoic acid (PFPeA) | < 3 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorotetradecanoic acid (PFTA) | < 8 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluorotridecanoic acid (PFTrDA) | < 7 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
| Perfluoroundecanoic acid (PFUnA) | < 2 ng/L | No federal or state limit; shown for transparency | Not detected above the reporting limit | 2024-01-08 to 2024-10-08 | UCMR5 Analytical Results: OSU WATER PLANT (OK1020910) |
Screening tells you if something is worth a closer look; a lab result is the number you can act on.
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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.
Get PurityMap updates about this water system.
Follow this water →According to EPA's record, Osu Water Plant uses surface water from its own intake, and buys water from Stillwater Utilities Authority.
EPA's record shows 13 health-based violations for Osu Water Plant in the 10 years to July 9, 2026. No open health-based violations on EPA record in the last 10 years. The latest legal-limit breach on record was in the period starting July 2025. EPA also lists 3 missed or late tests or reports in 10 years. The record comes from EPA's SDWIS compliance database.
Lead was not detected at the 90th percentile of tap samples in Osu Water Plant's latest lead and copper round, which ended in December 2026. The federal action level is 15 µg/L.
PurityMap has no verified website for Osu Water Plant. Your water bill lists the ways to contact your supplier and pay. PurityMap does not take payments.