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Milford Colony Inc

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
67 people
Connections
11
Water source
Groundwater
Based in
Wolf Creek, MT
County
Lewis and Clark
Owner
Private
Hardness
Soft

The short answer

1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Arsenic, above the legal limit. 5 health-based violations since 2016.

What handles it

What was found

Arsenic, uranium, fluoride, nitrate, chromium (total), haloacetic acids (HAA5) and total trihalomethanes (TTHM): Montana’s own results, samples taken from April 19, 2022 to June 3, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Arsenic

Comes from the source

Above the legal limit

44.8ppb

Highest yearly average, 2022 to 2026

2026: not found

Averaged by year, the highest was 44.8 ppb, in 2023, about 4.5 times EPA’s legal limit of 10 ppb. Its highest single sample was 53 ppb. In 2026, the latest year on file, it wasn’t found in any of its two samples. EPA recorded violations for arsenic at this utility in 2023, 2024 and 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 46.2 ppb, in 2012, and EPA recorded a violation in 2012.

What handles it

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

Above the health goal1

Uranium

Comes from the source

Above the health goal

0.45ppb

Highest yearly average, 2022 to 2026

Averaged by year, the highest was 0.45 ppb, in 2026: below EPA’s legal limit of 30 ppb, but above its health goal of zero. Its highest single sample was 0.5 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 2.0 ppb, in 2016.

What handles it

Below EPA’s limits2

Fluoride

Forms or is added in treatment

Below EPA’s limits

2.0ppm

Highest yearly average, 2022 to 2025

Averaged by year, the highest was 2.0 ppm, in 2025, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 2.8 ppm. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 1.1 ppm, in 2012.

What handles it

Nitrate

Comes from the source

Below EPA’s limits

3.3ppm

One sample

2024, one sample: 3.3 ppm

The highest sample, in 2024, was 3.3 ppm, below EPA’s legal limit of 10 ppm. That is the only year on file, and its one sample was 3.3 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 7.9 ppm, in 2012.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”
4 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Chromium (total)
  • Haloacetic acids (HAA5)
  • 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: Arsenic (Pentavalent)<=50 ppb Reduction

    For: Arsenic

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

  • NSF/ANSI 58

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

    For: Arsenic, Uranium

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

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

Compare five-year costs

The best reverse osmosis systems, ranked

Hardness

Soft, 5 mg/L (0.3 grains per gallon), at its one sampling point, in 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 0.3 grains per gallon, salt includedSoftener or salt-free conditioner?Montana water hardness, utility by utility

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageApril 1, 2025 to June 30, 20250.039 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJan. 1, 2025 to March 31, 20250.032 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageOct. 1, 2024 to Dec. 31, 20240.024 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2024 to Sept. 30, 20240.024 MG/LArchived
ArsenicThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2023 to Sept. 30, 20230.046 MG/LArchived
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 93 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Arsenic, uranium, fluoride, nitrate, chromium (total), haloacetic acids (HAA5) and total trihalomethanes (TTHM) results here are Montana’s own from 2022 on, with EPA’s national file for 2012 to 2019. Milford Colony Inc’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 April 19, 2022 to June 3, 2026.

Testing your own tap

Milford Colony Inc’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.

No lab Montana certifies is within 75 miles of the area Milford Colony Inc 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 Montana

Sources

PWSID MT0001646. Rebuilt from EPA data on Oct. 18, 2026.

Also in Lewis and Clark County

All Montana utilities

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