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City of LewistownWater quality report

Serves
5,923
Connections
2,906
Water source
Groundwater
Based in
Lewistown, MT
County
Fergus
Owner
Local government
The ZIP code it serves

59457

PWSID MT0000271 · EPA data

Read this first

Nothing in the federal data for this utility is above a health goal. That covers PFAS, lithium, lead and copper; it does not cover everything, so read what this report cannot tell you below.

1 health-based violation since 2016. Details are below.

What was found, stop by stop

  • Below the health goal
  • Above the health goal
  • Above the legal limit
  • No federal data

  1. At the source

    EPA UCMR 5 sampled this utility for 29 PFAS and lithium from Feb. 18, 2025 to Aug. 18, 2025. None was found above EPA’s reporting levels.

  2. In treatment

    No federal results for this stop. Disinfection byproduct, chlorine and fluoride levels are in City of Lewistown’s own annual report, which it must send you every year.

  3. In the pipes

    No lead and copper results on file with EPA for this utility.

  4. At your tap

    The last stretch is your own plumbing. A certified lab test is the only way to know what reaches your glass. Lead in your water: what to do

Tested and not found

Below EPA’s minimum reporting level in every sample taken from Feb. 18, 2025 to Aug. 18, 2025. Not found means not measured above that level, which is not the same as zero.

All 31 compounds tested and not found
  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • Lead
  • Lithium
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFBS
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

Contaminant or ruleTypePeriodMeasuredStatus
Coliform (TCR)Too many samples in a month tested positive for coliform bacteria.EPA: Maximum Contaminant Level Violation, Monthly (TCR)March 1, 2016 to March 31, 2016—Resolved
Health-based violations only. Resolved and archived mean the utility returned to compliance or the state closed the record. 4 monitoring or reporting violations not shown.

What this report cannot tell you

  • Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in City of Lewistown’s own annual report, which it must send you every year.
  • 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.
  • Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from Feb. 18, 2025 to Aug. 18, 2025.

Other Montana utilities

All Montana utilities

Sources

What to do next

  1. Every contaminant TapBuff tracks

    Nothing here is above a health goal in the federal data, which does not cover everything.

  2. Read the utility’s own report

    City of Lewistown must send you a water quality report every year. It lists nitrate, arsenic and byproduct levels this page cannot.

  3. Test your own tap for lead

    Your service line, solder and fixtures decide the lead at your faucet, not the utility’s average.

  4. NSF/ANSI standards, decoded

    A filter for taste or chlorine is a preference, not a need. The standards say what each kind can do.