Skip to content
TapBuff
ZIP

Sweetgrass Water Users Assn

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
100 people
Connections
98
Water source
Surface water bought from another system
Based in
Sweetgrass, MT
County
Toole
Owner
Private
The ZIP code it serves

59484

The short answer

1 result is above EPA’s legal limit, and 1 more is above the health goal. The worst: Total trihalomethanes (TTHM), above the legal limit. 1 health-based violation since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2010 to 2018.

Copper: EPA’s file records a utility’s copper only when it exceeds the action level. The last here was 1.5 ppm, for the period ending Dec. 31, 2013. None since is on file, so it is not counted as a current finding.

Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate: Montana’s own results, samples taken from Aug. 14, 2020 to Aug. 3, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the legal limit1

Total trihalomethanes (TTHM)

Forms or is added in treatment

Above the legal limit

77.3ppb

Highest yearly average, 2020 to 2026

2026 average: 65.5 ppb

Averaged by year, the highest was 77.3 ppb, in 2020, below EPA’s legal limit of 80 ppb. Its highest single sample was 98.9 ppb. In 2026, the latest year on file, its two samples averaged 65.5 ppb. EPA judges this limit at each sampling point, and recorded a violation for total trihalomethanes (TTHM) at this utility in 2025. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 86.5 ppb, in 2014, and EPA recorded a violation in 2015.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Above the health goal1

Lead

Comes from pipes, often your own

Above the health goal

15ppb

90th percentile, 2016 to 2018

In the latest period, 9 in 10 homes sampled were at or below 15 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027, and this result is at or above that. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits2

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

44.8ppb

Highest yearly average, 2020 to 2026

2026 average: 44 ppb

Averaged by year, the highest was 44.8 ppb, in 2023, below EPA’s legal limit of 60 ppb. Its highest single sample was 66.5 ppb. In 2026, the latest year on file, its two samples averaged 44 ppb. EPA recorded no violation for haloacetic acids (HAA5) at this utility since 2020. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 39.6 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

0.27ppm

Highest sample; found in 7 of 7

2026, one sample: 0.052 ppm

The highest sample, in 2021, was 0.27 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its one sample was 0.052 ppm.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

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: Trihalomethanes (TTHM) Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Lead

    Other certifiers’ wording: VOC Reduction

  • NSF/ANSI 58

    Claims: Trihalomethanes (TTHM) Reduction, Lead Reduction

    For: Total trihalomethanes (TTHM), Lead

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 water filters for lead, ranked

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
TTHMThe running average was above the legal limit.EPA: Maximum Contaminant Level Violation, AverageJuly 1, 2025 to Sept. 30, 20250.083 MG/LResolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 16 monitoring or reporting violations not shown.

What this report can’t tell you

  • Everything else. Total trihalomethanes (TTHM), haloacetic acids (HAA5) and nitrate results here are Montana’s own from 2020 on, with EPA’s national file for 2012 to 2019. Sweetgrass Water Users Assn’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 Aug. 14, 2020 to Aug. 3, 2026.

Testing your own tap

Sweetgrass Water Users Assn’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 Sweetgrass Water Users Assn 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 MT0000340. Rebuilt from EPA data on Oct. 18, 2026.

Also in Toole County

All Montana utilities

What to do next