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Huntley Yellowstone Co Water and Sewer

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
230 people
Connections
150
Water source
Groundwater
Based in
Huntley, MT
County
Yellowstone
Owner
Local government
Hardness
Very hard
The ZIP code it serves

59037

The short answer

2 results are above the health goal. The worst: Arsenic, above the health goal. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2007 to 2024.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.6 ppm, for the period ending Dec. 31, 2016. None since is on file, so it is not counted as a current finding.

Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, nitrate, chromium (total) and uranium: Montana’s own results, samples taken from Dec. 9, 2020 to Sept. 16, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

2.5ppb

Highest yearly average, 2022 to 2024

2024 average: 2.5 ppb

Averaged by year, the highest was 2.5 ppb, in 2022: below EPA’s legal limit of 10 ppb, but above its health goal of zero. Its highest single sample was 3.0 ppb. In 2024, the latest year on file, its two samples averaged 2.5 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 3.0 ppb, in 2013.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Lead

Comes from pipes, often your own

Above the health goal

2.0ppb

90th percentile, 2022 to 2024

In the latest period, 9 in 10 homes sampled were at or below 2.0 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

Below EPA’s limits4

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

26ppb

Highest yearly average, 2021 to 2025

2025, one sample: 5.1 ppb

Averaged by year, the highest was 26 ppb, in 2021, below EPA’s legal limit of 80 ppb. In 2025, the latest year on file, its one sample was 5.1 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 9.7 ppb, in 2013.

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

Below EPA’s limits

15ppb

Highest yearly average, 2021 to 2025

2025, one sample: 2.4 ppb

Averaged by year, the highest was 15 ppb, in 2021, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, its one sample was 2.4 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 8.6 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.55ppm

Highest yearly average, 2022

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. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.55 ppm, in 2013.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

0.59ppm

Highest sample; found in 9 of 16

2026 average: 0.17 ppm

The highest sample, in 2025, was 0.59 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its two samples averaged 0.17 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 0.38 ppm, in 2016.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
2 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • Uranium

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: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: 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

Compare five-year costs

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Hardness

Very hard, typically 259 mg/L (15.2 grains per gallon), across 4 sampling points, 2017 to 2025.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 15.2 grains per gallon, salt includedSoftener or salt-free conditioner?Montana water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Lead and Copper RuleA required study or plan for corrosion control was not done on time.EPA: OCCT/SOWT Study/RecommendationApril 10, 2017—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 3 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, nitrate, chromium (total) and uranium results here are Montana’s own from 2020 on, with EPA’s national file for 2012 to 2019. Huntley Yellowstone Co Water and Sewer’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 Dec. 9, 2020 to Sept. 16, 2026.

Testing your own tap

Huntley Yellowstone Co Water and Sewer’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Montana certifies.

The lab Montana certifies closest to the area Huntley Yellowstone Co Water and Sewer 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 15 miles

    Certified for bacteria, minerals and other inorganics, organic chemicals

    (800) 735-4489

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 Montana

Sources

PWSID MT0000254. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Yellowstone County

All Montana utilities

What to do next