Hat Rock Water Company
What EPA’s and CDC’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
- 150 people
- Connections
- 41
- Water source
- Groundwater
- Based in
- Hermiston, OR
- County
- Umatilla
- Owner
- Private
The ZIP code it serves
The short answer
1 result is above the health goal. The worst: Uranium, above the health goal. 4 health-based violations since 2016.
What handles itWhat was found
Uranium, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5) and arsenic: Oregon’s yearly averages per water system, as CDC’s Environmental Public Health Tracking Network publishes them, 2020 to 2023, with EPA’s 2012 to 2019 file for earlier years.
Above the health goal1
Uranium
Comes from the source
3.6ppb
Highest yearly average, 2023
Averaged by year, the highest was 3.6 ppb, in 2023: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 4.2 ppb, in 2014.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits3
Nitrate
Comes from the source
6.0ppm
Highest yearly average, 2020 to 2023
Averaged by year, the highest was 6.0 ppm, in 2023, 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 14 ppm, in 2016, and EPA recorded violations in 2014, 2015, 2016 and 2017.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Total trihalomethanes (TTHM)
Forms or is added in treatment
27.4ppb
Highest yearly average, 2022
Averaged by year, the highest was 27.4 ppb, in 2022, below EPA’s legal limit of 80 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 14.2 ppb, in 2014.
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
6.1ppb
Highest yearly average, 2022
Averaged by year, the highest was 6.1 ppb, in 2022, below EPA’s legal limit of 60 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.7 ppb, in 2014.
What handles it
No certification claim covers this compound yet.
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- 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 |
|---|---|---|---|---|
| Revised Total Coliform Rule | Coliform results required a check of the system, and the check or its fixes were not done on time.EPA: Treatment Technique, Level 1 Assessment (RTCR) | July 22, 2019 | — | Resolved |
| Nitrate | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Jan. 1, 2017 to March 31, 2017 | 12.6 MG/L | Resolved |
| Nitrate | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | July 1, 2016 to Sept. 30, 2016 | 11.6 MG/L | Resolved |
| Nitrate | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Jan. 1, 2016 to March 31, 2016 | 14 MG/L | Resolved |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 69 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Uranium, nitrate, total trihalomethanes (TTHM), haloacetic acids (HAA5) and arsenic results here are Oregon’s yearly averages as CDC publishes them, from 2020 on, with EPA’s national file for 2012 to 2019. Hat Rock Water Company’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; CDC’s yearly averages for Oregon cover 2020 to 2023.
Testing your own tap
The 3 labs Oregon certifies closest to the area Hat Rock Water Company serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Pendleton Wastewater Treatment Plant
Pendleton, OR · about 26 miles
Certified for bacteria
Umpqua Research Company - Table Rock
Pendleton, OR · about 26 miles
Certified for bacteria, nitrate
Matrix Sciences dba KTL
Pasco, WA · about 40 miles
Certified for nitrate, lead and copper, metals, minerals and other inorganics
Oregon State University Extension Well Water Program: Nitrate screening of well water at many of its groundwater education events. The screening is free. Water Testing Guidance for Private Wells, OSU Well Water Program.
All 91 certified labs for OregonSources
- 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 Oregon supplied to CDC, 2020 to 2023, read Oct. 8, 2026. TapBuff’s comparisons with EPA’s limits are its own, not CDC’s or Oregon’s.
- EPA Six-Year Review 4 compliance monitoring data, 2012 to 2019, file of Feb. 5, 2024
- Certified labs: Oregon Environmental Laboratory Accreditation Program, drinking water labs, as listed in TNI LAMS, read Oct. 13, 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 OR4101309. 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 reportHat Rock Water Company 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