King Ranch Colony
What EPA’s and Montana’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
- 56 people
- Connections
- 17
- Water source
- Groundwater
- Based in
- Lewistown, MT
- County
- Fergus
- Owner
- Private
The short answer
1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Nitrate, above the legal limit. 24 health-based violations since 2016.
What handles itWhat was found
Nitrate, uranium, fluoride, arsenic, chromium (total) and total trihalomethanes (TTHM): Montana’s own results, samples taken from March 23, 2020 to Sept. 30, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit1
Nitrate
Comes from the source
36.2ppm
Highest sample; found in 28 of 28
2026 average: 11.5 ppm
From 2020 to 2026, at least 25 samples were above EPA’s legal limit of 10 ppm, the highest 36.2 ppm in 2024. 25 have no follow-up sample on file within 30 days. In 2026, the latest year on file, its three samples averaged 11.5 ppm, above the limit. EPA recorded violations for nitrate at this utility in 2020, 2021, 2022, 2023, 2024, 2025 and 2026. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 17.9 ppm, in 2013, and EPA recorded violations in 2012, 2013, 2014, 2015 and 2019.
What handles it
- NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
- NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
Above the health goal1
Uranium
Comes from the source
1.3ppb
Highest yearly average, 2022
Averaged by year, the highest was 1.3 ppb, in 2022: 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 1.0 ppb, in 2012.
What handles it
- NSF/ANSI 58 look for “Uranium”
Below EPA’s limits1
Fluoride
Forms or is added in treatment
0.3ppm
Highest yearly average, 2022
Averaged by year, the highest was 0.3 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.3 ppm, in 2012.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Arsenic
- Chromium (total)
- Lead
- Total trihalomethanes (TTHM)
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 53
Claim: Nitrate/Nitrite (30 ppm challenge)
For: Nitrate
- NSF/ANSI 58
Claims: Nitrate/Nitrite Reduction, Uranium
For: Nitrate, Uranium
Other certifiers’ wording: Nitrate
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
Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money
Countertop reverse osmosis
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 4, 2026
Certified for: Nitrate
Aquasana SmartFlow Reverse Osmosis (AQ-SFRO2)
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate
Violations since 2016
| Contaminant or rule | Type | Period | Measured | Status |
|---|---|---|---|---|
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2026 to June 30, 2026 | 11.5 MG/L | Archived |
| Nitrate-Nitrite | 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, 2026 to March 31, 2026 | 12.3 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2025 to Dec. 31, 2025 | 10.7 MG/L | Archived |
| Nitrate-Nitrite | 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, 2025 to Sept. 30, 2025 | 13 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2025 to June 30, 2025 | 13.9 MG/L | Archived |
| Nitrate-Nitrite | 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, 2025 to March 31, 2025 | 11.3 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2024 to Dec. 31, 2024 | 36.2 MG/L | Archived |
| Nitrate-Nitrite | 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, 2024 to Sept. 30, 2024 | 12.1 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2024 to June 30, 2024 | 12.3 MG/L | Archived |
| Nitrate-Nitrite | 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, 2024 to March 31, 2024 | 11.9 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2023 to Dec. 31, 2023 | 10.6 MG/L | Archived |
| Nitrate-Nitrite | 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, 2023 to Sept. 30, 2023 | 10.7 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2023 to June 30, 2023 | 12.1 MG/L | Archived |
| Nitrate-Nitrite | 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, 2023 to March 31, 2023 | 13 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2022 to Dec. 31, 2022 | 12.5 MG/L | Archived |
| Nitrate-Nitrite | 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, 2022 to Sept. 30, 2022 | 12.3 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2022 to June 30, 2022 | 12.3 MG/L | Archived |
| Nitrate-Nitrite | 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, 2022 to March 31, 2022 | 12.7 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2021 to Dec. 31, 2021 | 12 MG/L | Archived |
| Nitrate-Nitrite | 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, 2021 to Sept. 30, 2021 | 12.4 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | April 1, 2021 to June 30, 2021 | 12.6 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2020 to Dec. 31, 2020 | 11.7 MG/L | Archived |
| Nitrate-Nitrite | 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, 2020 to March 31, 2020 | 10.6 MG/L | Archived |
| Nitrate-Nitrite | A sample was above the legal limit, for a contaminant judged one sample at a time.EPA: Maximum Contaminant Level Violation, Single Sample | Oct. 1, 2019 to Dec. 31, 2019 | 15.5 MG/L | Archived |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 63 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, uranium, fluoride, arsenic, chromium (total) and total trihalomethanes (TTHM) results here are Montana’s own from 2020 on, with EPA’s national file for 2012 to 2019. King Ranch Colony’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; Montana’s results run from March 23, 2020 to Sept. 30, 2026.
Testing your own tap
No lab Montana certifies is within 75 miles of the area King Ranch Colony serves on the state’s list. Some take samples by mail; the state’s page lists them all.
Montana State Environmental Laboratory: Private well testing packages for bacteria, metals, nutrients, anions, organic chemicals and more, open to the public. Samples can be mailed, sent by the lab's free courier, or dropped off at the lab. Environmental Laboratory, Montana Department of Public Health and Human Services.
All 36 certified labs for MontanaSources
- EPA UCMR 5 occurrence data, file of Oct. 15, 2026
- EPA SDWA bulk download (SDWIS federal data), 2026 Q3
- Montana Department of Environmental Quality, Public Water Supply, results from Jan. 2, 2020 to Oct. 6, 2026, read Oct. 18, 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 MT0000432. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 2 results above a lineWhat each one does to health, where it comes from, and the certification claim that addresses it.Start with Nitrate
- Get the utility’s own reportKing Ranch Colony 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