Worden Ballantine Yellowstone
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
- 800 people
- Connections
- 320
- Water source
- Groundwater
- Based in
- Ballantine, MT
- County
- Yellowstone
- Owner
- Local government
The short answer
1 result is above EPA’s legal limit, and 3 more are above the health goal. The worst: Nitrate, above the legal limit. 8 health-based violations since 2016.
What handles itWhat was found
Lead and copper: EPA SDWIS monitoring periods ending 2015 to 2025.
Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 2.5 ppm, for the period ending Sept. 30, 1999. None since is on file, so it is not counted as a current finding.
Nitrate, uranium, arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total): Montana’s own results, samples taken from Jan. 20, 2020 to Sept. 29, 2026, with EPA’s 2012 to 2019 file for earlier years.
Above the legal limit1
Nitrate
Comes from the source
12.4ppm
Highest sample; found in 84 of 84
2026 average: 2.9 ppm
From 2020 to 2025, 13 samples were above EPA’s legal limit of 10 ppm, the highest 12.4 ppm in 2025. The next sample at the same point, within 30 days, kept the average above the limit for nine; four have no follow-up sample on file within 30 days. In 2026, the latest year on file, its nine samples averaged 2.9 ppm. EPA recorded violations for nitrate at this utility in 2020, 2021, 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 12.4 ppm, in 2019, and EPA recorded a violation in 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 goal3
Uranium
Comes from the source
11.8ppb
Highest yearly average, 2025
Averaged by year, the highest was 11.8 ppb, in 2025: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 12.3 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 10.3 ppb, in 2019.
What handles it
- NSF/ANSI 58 look for “Uranium”
Lead
Comes from pipes, often your own
3.0ppb
90th percentile, 2023 to 2025
In the latest period, 9 in 10 homes sampled were at or below 3.0 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.
What handles it
- NSF/ANSI 53 look for “Lead Reduction”
- NSF/ANSI 58 look for “Lead Reduction”
Arsenic
Comes from the source
2.0ppb
Highest yearly average, 2020 to 2025
2025 average: 1.5 ppb
Averaged by year, the highest was 2.0 ppb, in 2020: below EPA’s legal limit of 10 ppb, but above its health goal of zero. In 2025, the latest year on file, its two samples averaged 1.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2016.
What handles it
- NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
- NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
Below EPA’s limits3
Total trihalomethanes (TTHM)
Forms or is added in treatment
37ppb
Highest yearly average, 2020 to 2026
2026, one sample: 14 ppb
Averaged by year, the highest was 37 ppb, in 2024, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 14 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 41 ppb, in 2018.
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
20ppb
Highest yearly average, 2020 to 2026
2026, one sample: 3.5 ppb
Averaged by year, the highest was 20 ppb, in 2024, below EPA’s legal limit of 60 ppb. In 2026, the latest year on file, its one sample was 3.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 12.8 ppb, in 2013.
What handles it
No certification claim covers this compound yet.
Fluoride
Forms or is added in treatment
0.55ppm
Highest yearly average, 2022 to 2025
2025 average: 0.35 ppm
Averaged by year, the highest was 0.55 ppm, in 2022, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 0.6 ppm. In 2025, the latest year on file, its two samples averaged 0.35 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.6 ppm, in 2016.
What handles it
- NSF/ANSI 58 look for “Fluoride Reduction”
- NSF/ANSI 53 look for “Fluoride”
One compound tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
- Chromium (total)
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
Claims: Nitrate/Nitrite (30 ppm challenge), Lead Reduction, Arsenic (Pentavalent)<=50 ppb Reduction
For: Nitrate, Lead, Arsenic
Other certifiers’ wording: Arsenic (III) (50 ppb influent level)
- NSF/ANSI 58
Claims: Nitrate/Nitrite Reduction, Uranium, Lead Reduction, Arsenic (Pentavalent)<=50 ppb Reduction
For: Nitrate, Uranium, Lead, Arsenic
Other certifiers’ wording: Nitrate; Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)
At the tap, or for the whole house?
Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. 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, Lead, Arsenic
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, Lead, Arsenic
Culligan 10-Cup Pitcher with ZeroWater Technology (ZEROP10)
Pitcher
- IAPMO listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 401checked Oct. 9, 2026
Certified for: Nitrate, Lead
Brondell Capella RC250 Reverse Osmosis System
Under-sink reverse osmosis
- WQA listing:NSF/ANSI 42NSF/ANSI 53NSF/ANSI 58NSF/ANSI 401checked Oct. 9, 2026
Certified for: Lead, Arsenic
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, 2025 to June 30, 2025 | 11.2 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 | Jan. 1, 2025 to March 31, 2025 | 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 | Jan. 1, 2024 to March 31, 2024 | 11 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 | 10 MG/L | Archived |
| Surface Water Treatment Rule | Water drawn from a river, lake or reservoir was not filtered as required.EPA: Failure to Filter (SWTR) | March 22, 2021 | — | Unaddressed |
| 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, 2020 to June 30, 2020 | 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 | Jan. 1, 2020 to March 31, 2020 | 10.1 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, 2019 to June 30, 2019 | 12 MG/L | Archived |
| Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 9 monitoring or reporting violations not shown. | ||||
What this report can’t tell you
Everything else. Nitrate, uranium, arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride and chromium (total) results here are Montana’s own from 2020 on, with EPA’s national file for 2012 to 2019. Worden Ballantine Yellowstone’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 Jan. 20, 2020 to Sept. 29, 2026.
Testing your own tap
The lab Montana certifies closest to the area Worden Ballantine Yellowstone serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.
Energy Laboratories, Inc.
Billings, MT · about 27 miles
Certified for bacteria, minerals and other inorganics, organic chemicals
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
- Certified labs: Montana Department of Public Health and Human Services, Water Laboratory Certification Program, certified laboratories, 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 MT0000022. Rebuilt from EPA data on Oct. 18, 2026.
What to do next
- Read up on the 4 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 reportWorden Ballantine Yellowstone 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