Coalby Domestic WC
What EPA’s and Colorado’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.
- Serves
- 239 people
- Connections
- 128
- Water source
- Groundwater influenced by surface water
- Based in
- Cedaredge, CO
- County
- Delta
- Owner
- Private
The short answer
1 result is above the health goal. The worst: Uranium, above the health goal. 16 health-based violations since 2016.
What handles itWhat was found
Uranium, haloacetic acids (HAA5), total trihalomethanes (TTHM), nitrate, arsenic, chromium (total) and fluoride: Colorado’s own results, samples taken from March 31, 2020 to Aug. 12, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the health goal1
Uranium
Comes from the source
0.3ppb
Highest yearly average, 2025
Averaged by year, the highest was 0.3 ppb, in 2025: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits3
Haloacetic acids (HAA5)
Forms or is added in treatment
12.4ppb
Highest yearly average, 2022 to 2026
2026, one sample: 3.7 ppb
Averaged by year, the highest was 12.4 ppb, in 2022, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 3.7 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.2 ppb, in 2014.
What handles it
No certification claim covers this compound yet.
Total trihalomethanes (TTHM)
Forms or is added in treatment
14.3ppb
Highest yearly average, 2020 to 2026
2026, one sample: 4.8 ppb
Averaged by year, the highest was 14.3 ppb, in 2021, below EPA’s legal limit of 80 ppb. Its highest single sample was 29 ppb. In 2026, the latest year on file, its one sample was 4.8 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 12.6 ppb, in 2014.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Nitrate
Comes from the source
0.41ppm
Highest sample; found in 7 of 7
2026, one sample: 0.3 ppm
The highest sample, in 2020, was 0.41 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.38 ppm, in 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Fluoride
- Lead
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 costsViolations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Interim Enhanced Surface Water Treatment Rule | Too many readings in a month showed cloudiness above the filtration standard.EPA: Monthly Turbidity Exceed (Enhanced SWTR) | May 1, 2022 to May 31, 2022 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2022 to Jan. 31, 2022 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2017 to Feb. 28, 2017 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2017 to Jan. 31, 2017 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Dec. 1, 2016 to Dec. 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Nov. 1, 2016 to Nov. 30, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Oct. 1, 2016 to Oct. 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Sept. 1, 2016 to Sept. 30, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Aug. 1, 2016 to Aug. 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | July 1, 2016 to July 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | June 1, 2016 to June 30, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | May 1, 2016 to May 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | April 1, 2016 to April 30, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | March 1, 2016 to March 31, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Feb. 1, 2016 to Feb. 29, 2016 | — | Resolved |
| Surface Water Treatment Rule | Required treatment for surface water or groundwater was not met.EPA: Treatment Technique (SWTR and GWR) | Jan. 1, 2016 to Jan. 31, 2016 | — | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 178 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Uranium, haloacetic acids (HAA5), total trihalomethanes (TTHM), nitrate, arsenic, chromium (total) and fluoride results here are Colorado’s own from 2020 on, with EPA’s national file for 2012 to 2019. Coalby Domestic WC’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 didn’t sample this utility; Colorado’s results run from March 31, 2020 to Aug. 12, 2026.
Testing your own tap
No lab Colorado certifies is within 75 miles of the area Coalby Domestic WC serves on the state’s list. Some take samples by mail; the state’s page lists them all.
All 54 certified labs for ColoradoSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Colorado Department of Public Health and Environment, Water Quality Control Division, results from Jan. 3, 2020 to Oct. 6, 2026, read Oct. 17, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Limits and goals: each contaminant’s page, with its EPA source.
- How this page is built: methodology.
PWSID CO0115185. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on UraniumWhat each one does to health, where it comes from, and the certification claim that addresses it.About Uranium
- Get the utility’s own reportCoalby Domestic WC 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
- Compare certified filtersWhat the filters certified for these results cost over five years, cartridges included.Compare five-year costs