Greystone MHP
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
- 500 people
- Connections
- 163
- Water source
- Groundwater
- Based in
- Watertown, MN
- County
- Anoka
- Owner
- Private
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. No health-based violations on file since 2016.
What was found
Total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic and nitrate: Minnesota’s yearly summaries per water system, 2023 to 2025, with EPA’s 2012 to 2019 file for earlier years.
Chromium (total) and fluoride: EPA’s compliance monitoring file, samples taken from June 25, 2014 to June 25, 2014. Newer results are in the utility’s annual water quality report.
Below EPA’s limits2
Total trihalomethanes (TTHM)
Forms or is added in treatment
9.1ppb
Highest yearly average, 2023 to 2025
2025 average: 7.8 ppb
Averaged by year, the highest was 9.1 ppb, in 2023, below EPA’s legal limit of 80 ppb. In 2025, the latest year on file, it averaged 7.8 ppb.
What handles it
- NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
- NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
Haloacetic acids (HAA5)
Forms or is added in treatment
6.5ppb
Highest yearly average, 2023 to 2025
2025 average: 5.4 ppb
Averaged by year, the highest was 6.5 ppb, in 2024, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, it averaged 5.4 ppb.
What handles it
No certification claim covers this compound yet.
5 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Fluoride
- Lead
- Nitrate
Violations since 2016
No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.
What this report can’t tell you
Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5), arsenic and nitrate results here are Minnesota’s own yearly summaries from 2023 on, with EPA’s national file for 2012 to 2019. Chromium (total) and fluoride come from EPA’s file alone, which ends in 2019. Greystone MHP’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 2023 to 2025; EPA’s compliance samples are from June 25, 2014 to June 25, 2014.
Testing your own tap
The 3 labs Minnesota certifies closest to the area Greystone MHP serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Water Laboratories, Inc.
Elk River, MN · about 18 miles
Certified for bacteria, nitrate, lead and copper, metals
Instrumental Research, Inc.
Fridley, MN · about 21 miles
Certified for bacteria, nitrate
EMSL Analytical, Inc.
New Hope, MN · about 28 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 MN1020005. 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 reportGreystone MHP 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