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Stillwater, OK Tap Water Quality 2026

Water quality report for Stillwater, OK — PFAS, lead and copper results, violation history and state inspection findings from EPA SDWIS.

A look at Stillwater's drinking water using EPA enforcement records: violations, lead and copper results, PFAS sampling and state inspection findings.

Main Utility: Stillwater Utilities Authority PWSID: OK1021220 Updated: 2026 Q2
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PFAS above the federal limit

Lead is 2.10 ppb, 14% of the action level and no violations are open. However, PFAS exceeds the federal limit at 1 of 1 sampling points, running as high as 1.53 times the limit.

C

Stillwater earns a C for water quality

Graded on violations, lead, and PFAS, with state inspection findings.

Lead: 2.10 ppb — 14% of the federal action level
PFAS above the federal limit at 1 of 1 sampling points
21 violations since 2015, 16 health-based
No violations currently open
Stillwater's lead level vs. all Oklahoma community water systems
0 ppb5 ppb10 ppb15 ppb
Lead level: 2.10 ppb — 14% of the federal action level
✓ Lower lead than 47% of Oklahoma utilities
Population Served
45047
~17348 connections
Water Source
Surface water
Drawn from surface water — SDWIS source code SW
Active Violations
0
21 since 2015, all resolved

Lead & Copper Testing

Lead (Pb)
90th percentile of tap samples collected across the distribution system
14% of EPA action level
2.10 ppb
Action level: 15 ppb
The 90th-percentile lead result is 2.10 ppb, 14% of the 15 ppb federal action level. The action level is a treatment trigger, not a legal maximum, and it is measured across sampled taps rather than at any single home.

Contaminant Violations (2015–Present)

ContaminantTypeMeasuredLimitPeriodStatus
Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2023 Resolved
Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2023 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE 0.98 RATIO TT 2022 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE 0.96 RATIO TT 2022 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE 0.94 RATIO TT 2022 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE 0.9 RATIO TT 2021 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2018 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2018 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2018 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE — TT 2017 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2017 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2017 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE — TT 2017 Resolved
Bromate MONITORING AND REPORTING — 0.010 mg/L 2017 Resolved
CARBON, TOTAL MONITORING AND REPORTING — TT 2017 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE — TT 2017 Resolved
CARBON, TOTAL MONITORING AND REPORTING — TT 2016 Resolved
CARBON, TOTAL TREATMENT TECHNIQUE — TT 2016 Resolved
CARBON, TOTAL MONITORING AND REPORTING — TT 2016 Resolved
Interim Enhanced Surface Water Treatment Rule TREATMENT TECHNIQUE — — 2016 Resolved
Nitrate-Nitrite MONITORING AND REPORTING — — 2016 Resolved
Understanding violation types MCL violations mean a contaminant exceeded the federal maximum limit — the most serious type.
TT (Treatment Technique) violations mean required treatment procedures weren't followed, but don't necessarily mean contamination occurred.

Violation History

21 violations are on record since 2015, of which 16 were health-based. All have been resolved and none remain open.

About the Main Water System

Utility Stillwater Utilities Authority
PWSID OK1021220
Water source Surface water — Drawn from surface water — SDWIS source code SW
Population served 45,047
Service connections 17,348
Systems serving this area 4
Regulator State primacy agency
Data through 2026 Q2 — EPA SDWIS

Frequently Asked Questions

Is Stillwater tap water safe to drink? ▼
It meets most federal standards, but PFAS exceeds the federal limit at 1 of 1 sampling points. No violations are currently open. Lead is 2.10 ppb, 14% of the action level.
Does Stillwater water have PFAS? ▼
Yes. PFAS exceeds the federal limit at 1 of 1 sampling points, running as high as 1.53 times the limit. Limits are enforced on a running annual average at each sampling point, not on a single sample.
Who supplies water to Stillwater? ▼
Stillwater Utilities Authority (PWSID OK1021220), one of 4 systems serving this area. Surface water. Drawn from surface water — SDWIS source code SW
When was this system last inspected? ▼
It was last inspected on 2026-03-04. No significant deficiencies were recorded.

What Should Stillwater Residents Do?

1
Consider a reverse-osmosis filter
Reverse osmosis removes more than 95% of PFAS. Standard carbon pitchers do not.
2
Check for a lead service line
Lead reaches tap water mainly through service lines and household plumbing. Suppliers now publish an inventory identifying lead lines.
3
Flush before drinking
If water has sat in pipes more than six hours, run the cold tap for two minutes before drinking or cooking.

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