Comstock
What EPA’s and Minnesota’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
- 95 people
- Connections
- 52
- Water source
- Groundwater
- Based in
- Comstock, MN
- County
- Clay
- Owner
- Local government
The ZIP code it serves
The short answer
Nothing in EPA’s and Minnesota’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. 1 health-based violation since 2016.
What was found
Nitrate, haloacetic acids (HAA5) and total trihalomethanes (TTHM): Minnesota’s yearly summaries per water system, 2024 to 2025, with EPA’s 2012 to 2019 file for earlier years.
Fluoride, arsenic and chromium (total): EPA’s compliance monitoring file, samples taken from Feb. 28, 2012 to Oct. 23, 2019. Newer results are in the utility’s annual water quality report.
Below EPA’s limits2
Fluoride
Forms or is added in treatment
0.73ppm
Highest yearly average, 2012 to 2019
2019 average: 0.68 ppm
Averaged by year, the highest was 0.73 ppm, in 2014, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.76 ppm. In 2019, the latest year on file, its five samples averaged 0.68 ppm.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
Nitrate
Comes from the source
0.7ppm
Highest yearly average, 2024 to 2025
Averaged by year, the highest was 0.7 ppm, in 2025, below EPA’s legal limit of 10 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.36 ppm, in 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Haloacetic acids (HAA5)
- Lead
- Total trihalomethanes (TTHM)
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Stage 1 Disinfectants and Disinfection Byproducts Rule | Treatment was not run by a certified operator as required.EPA: Treatment Technique No Certif. Operator | Jan. 1, 2024 | — | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 12 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, haloacetic acids (HAA5) and total trihalomethanes (TTHM) results here are Minnesota’s own yearly summaries from 2024 on, with EPA’s national file for 2012 to 2019. Fluoride, arsenic and chromium (total) come from EPA’s file alone, which ends in 2019. Comstock’s own annual report, which it must send you every year, has newer results for those 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 didn’t sample this utility; Minnesota’s yearly summaries cover 2024 to 2025; EPA’s compliance samples are from Feb. 28, 2012 to Oct. 23, 2019.
Testing your own tap
The lab Minnesota certifies closest to the area Comstock serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
RMB Environmental Laboratories, Inc. – Detroit Lakes
Detroit Lakes, MN · about 46 miles
Certified for bacteria, nitrate, lead and copper, metals
Sources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Minnesota Department of Health, Minnesota Public Health Data Access, results from Jan. 1, 2023 to Dec. 31, 2025, read Oct. 8, 2026
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Minnesota Department of Health, accredited labs in Minnesota accepting drinking water samples from private well users, read Oct. 10, 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 MN1140002. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Nothing here is above a health goalIn EPA’s and Minnesota’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 reportComstock must send you a water quality report every year. It covers contaminants this page does not show, and has newer results than EPA’s national file for the ones here that come from it.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