Chickasaw Winstar Casino
What EPA’s records show in this utility’s water: PFAS and lithium; nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 8,376 people
- Connections
- 23
- Water source
- Groundwater
- Based in
- Ada, OK
- Owner
- Native American
The short answer
1 result is above the health goal, and 1 more is above EPA’s health benchmark. The worst: Lithium, above EPA’s health benchmark. No health-based violations on file since 2016.
What handles itWhat was found
PFAS and lithium: EPA UCMR 5, samples taken from March 4, 2024 to Sept. 23, 2024.
Uranium, total trihalomethanes (TTHM), fluoride, arsenic, chromium (total), haloacetic acids (HAA5) and nitrate: EPA’s compliance monitoring file, samples taken from Aug. 28, 2012 to Aug. 13, 2019. Newer results are in the utility’s annual water quality report.
PFAS: None of the six PFAS in EPA’s 2024 drinking water rule was found in this utility’s samples. None of the other 23 PFAS tested for was found either.
EPA’s 2024 PFAS rule, compound by compound
| PFAS | EPA’s limit | Result |
|---|---|---|
| PFOA | 4.0 ppt | Not foundNot found in any of 8 samples, below 4 ppt |
| PFOS | 4.0 ppt | Not foundNot found in any of 8 samples, below 4 ppt |
| PFHxS | 10 ppt | Not foundNot found in any of 8 samples, below 3 ppt |
| PFNA | 10 ppt | Not foundNot found in any of 8 samples, below 4 ppt |
| HFPO-DA (GenX) | 10 ppt | Not foundNot found in any of 8 samples, below 5 ppt |
| PFBS | Index only | Not foundNot found in any of 8 samples, below 3 ppt |
| Hazard IndexPFHxS, PFNA, HFPO-DA and PFBS together | 1 | Doesn’t applyDoesn’t apply: no sampling location found two or more of the four |
| Results from EPA’s UCMR 5 sampling. “Below” is the lab’s reporting level: a result under it reads as not found, which is not the same as zero. The limits are EPA’s 2024 rule, with compliance due from 2029; EPA has since proposed changes to some of them, explained on each compound’s page. PFBS has no limit of its own and counts only toward the Hazard Index, which adds up the four, each against EPA’s health-based level, from each sampling location’s average, as EPA’s UCMR 5 summary does. It counts only where two or more of the four were found, and is above the limit from 1.5. | ||
Above the health goal1
Uranium
Comes from the source
1.7ppb
Highest yearly average, 2014 to 2018
2018: not found
Averaged by year, the highest was 1.7 ppb, in 2015: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 8.6 ppb. In 2018, the latest year on file, it wasn’t found in its one sample.
What handles it
- NSF/ANSI 58 look for “Uranium”
Above EPA’s health benchmark1
Lithium
Comes from the source
23.4ppb
Highest sample, Sept. 23, 2024; found in 8 of 8
The highest sample was 23.4 ppb, about 2.3 times EPA’s health reference level of 10 ppb. That is a screening level, not an enforceable limit.
What handles it
No certification claim covers this compound yet.
Below EPA’s limits2
Total trihalomethanes (TTHM)
Forms or is added in treatment
10.9ppb
Highest yearly average, 2012 to 2019
2019 average: 8.4 ppb
Averaged by year, the highest was 10.9 ppb, in 2012, below EPA’s legal limit of 80 ppb. Its highest single sample was 12.9 ppb. In 2019, the latest year on file, its two samples averaged 8.4 ppb.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Fluoride
Forms or is added in treatment
0.21ppm
Highest yearly average, 2014 to 2018
2018, one sample: 0.15 ppm
Averaged by year, the highest was 0.21 ppm, in 2014, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.22 ppm. In 2018, the latest year on file, its one sample was 0.15 ppm.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
34 compounds tested and not foundIncluding all six PFAS in EPA’s 2024 rule. Below the reporting level in every sample. Not found is not the same as zero.
From routine monitoring
- Arsenic
- Chromium (total)
- Haloacetic acids (HAA5)
- Lead
- Nitrate
PFAS and lithium, from EPA’s UCMR 5 sampling
- 11Cl-PF3OUdS
- 4:2 FTS
- 6:2 FTS
- 8:2 FTS
- 9Cl-PF3ONS
- ADONA
- HFPO-DA (GenX)
- NEtFOSAA
- NFDHA
- NMeFOSAA
- PFBA
- PFBS
- PFDA
- PFDoA
- PFEESA
- PFHpA
- PFHpS
- PFHxA
- PFHxS
- PFMBA
- PFMPA
- PFNA
- PFOA
- PFOS
- PFPeA
- PFPeS
- PFTA
- PFTrDA
- PFUnA
What handles it
A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”
- NSF/ANSI 58
Claim: Uranium
For: Uranium
At the tap, or for the whole house?
These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.
Filters with those claims on a certifier’s listing
None of the filters TapBuff has checked so far carry these claims. Search the certifier listings for the claim above.
Compare five-year costsDisinfectant
Chickasaw Winstar Casino reported disinfecting with chlorine, not chloramine, at all 4 of its sampling points, in its 2024 sampling for EPA.
Chlorine leaves water that sits out for a few days, CDC says. A filter certified for it carries a chlorine claim under NSF/ANSI 42; a shower filter, a free chlorine claim under NSF/ANSI 177. This is what the utility reported for that sampling. Its annual water quality report says what it uses now.
Violations since 2016
No health-based violations on file with EPA since 2016.
What this report can’t tell you
Newer results, and everything else. Nitrate, arsenic, fluoride, chromium, uranium and disinfection byproduct results here come from EPA’s national compliance file, which ends in 2019. Chickasaw Winstar Casino’s own annual report, which it must send you every year, has newer results and the contaminants this page does not show.
Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.
What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.
Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 samples are from March 4, 2024 to Sept. 23, 2024; EPA’s compliance samples are from Aug. 28, 2012 to Aug. 13, 2019.
Testing your own tap
TapBuff hasn’t read Oklahoma’s list of certified labs yet. The national page links every state’s own list.
Certified labs, state by stateSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Disinfectant: EPA UCMR 5 occurrence data, additional data elements, file of Oct. 15, 2026
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID 062004336. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Lithium
- Get the utility’s own reportChickasaw Winstar Casino must send you a water quality report every year. It has newer results than EPA’s national file, which ends in 2019.How to read it
- Test your own tap for leadYour service line, solder and fixtures decide the lead at your faucet, not the utility’s average.Lead in your water: what to do
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs