Cs Old Concho Water Users
What EPA’s and CDC’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
- 40 people
- Connections
- 31
- Water source
- Groundwater bought from another system
- Based in
- Concho, AZ
- County
- Apache
- Owner
- Private
The ZIP code it serves
The short answer
Nothing in EPA’s and CDC’s records for this utility is above a health goal. That covers PFAS and lithium; nitrate, arsenic and other regulated chemicals; and lead and copper, not everything. 3 health-based violations since 2016.
What was found
PFAS and lithium: EPA UCMR 5, samples taken from June 1, 2025 to Jan. 13, 2026.
Total trihalomethanes (TTHM) and haloacetic acids (HAA5): Arizona’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2021.
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 2 samples, below 4 ppt |
| PFOS | 4.0 ppt | Not foundNot found in any of 2 samples, below 4 ppt |
| PFHxS | 10 ppt | Not foundNot found in any of 2 samples, below 3 ppt |
| PFNA | 10 ppt | Not foundNot found in any of 2 samples, below 4 ppt |
| HFPO-DA (GenX) | 10 ppt | Not foundNot found in any of 2 samples, below 5 ppt |
| PFBS | Index only | Not foundNot found in any of 2 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. | ||
Below EPA’s limits2
Lithium
Comes from the source
13ppb
Highest sample, June 1, 2025; found in 1 of 2
The highest sample was 13 ppb. As EPA rounds results, that is at EPA’s health reference level of 10 ppb, not above it: EPA counts a result as above it from 15 ppb.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
0.6ppb
Highest yearly average, 2021
Averaged by year, the highest was 0.6 ppb, in 2021, below EPA’s legal limit of 80 ppb. That is the only year on file.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
31 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
- Haloacetic acids (HAA5)
- Lead
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
Disinfectant
Cs Old Concho Water Users reported adding no disinfectant at its one sampling point, in its 2025 to 2026 sampling for EPA.
Most utilities add chlorine or chloramine, CDC says. This utility buys its water from another system, so what it reported may leave out treatment done before the water reaches it. This is what the utility reported for that sampling. Its annual water quality report says what it uses now.
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | July 7, 2019 | — | Resolved |
| Groundwater Rule | A significant problem found in a state inspection was not fixed on time.EPA: Failure To Address Deficiency | June 21, 2019 | — | Resolved |
| Revised Total Coliform Rule | Coliform or E. coli results required a detailed review of the system, and it or its fixes were not done on time.EPA: Treatment Technique, Level 2 Assessment (RTCR) | Aug. 14, 2016 | — | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 85 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM) and haloacetic acids (HAA5) results here are Arizona’s yearly averages as CDC publishes them, from 2021 on, with EPA’s national file for 2012 to 2019. Cs Old Concho Water Users’s own annual report, which it must send you every year, has 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 June 1, 2025 to Jan. 13, 2026; CDC’s yearly averages for Arizona cover 2021.
Testing your own tap
The 2 labs Arizona certifies closest to the area Cs Old Concho Water Users serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Sacred Water Testing LLC
Show Low, AZ · about 27 miles
Mohave Environmental Labs
Holbrook, AZ · about 35 miles
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- CDC Environmental Public Health Tracking Network, yearly averages Arizona supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Arizona’s.
- Disinfectant: EPA UCMR 5 occurrence data, additional data elements, file of Oct. 15, 2026
- Certified labs: Arizona Department of Health Services, Arizona certified commercial drinking water laboratories, read Oct. 17, 2026; distances from the Census 2020 ZIP code tabulation area gazetteer
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID AZ0401011. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and CDC’s records for this utility. They don’t cover everything, which is why the next step matters.Every contaminant TapBuff tracks
- Get the utility’s own reportCs Old Concho Water Users must send you a water quality report every year. It covers contaminants this page does not show.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
- Decide if you want a filter at allA filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.NSF/ANSI standards, decoded