Lewistown, MT
Contamination score
Higher = more contaminated vs. other cities.
Reported illness & cancer claims
No claims reported yet. Be the first to add one.
Claims are aggregated from public records and community reports and may be unverified. If you believe your illness is linked to local water, request a consultation.
Self-reported issues
No issues reported yet. Be the first to report one.

Public water systems
Spring Creek Colony Lewistown
- PWSID:
- MT0000433
- Source:
- Ground water
- Serves:
- 48 people
Deerfield Hutterite Colony
- PWSID:
- MT0000431
- Source:
- Ground water
- Serves:
- 51 people
King Ranch Colony
- PWSID:
- MT0000432
- Source:
- Ground water
- Serves:
- 56 people
Mountain Acres Mb Hm Pk
- PWSID:
- MT0003809
- Source:
- Ground water
- Serves:
- 320 people
Lewistown City Of
- PWSID:
- MT0000271
- Source:
- Ground water
- Serves:
- 5,923 people
EPA & DEP violations
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Oct 1, 2025 · 8 months ago · Source ↗
Consumer Confidence Rule — Other violation
medium severityResolvedConsumer Confidence Rule Other violation (Resolved).
EPA SDWIS · Other · Began Jul 1, 2025 · 11 months ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Jul 1, 2025 · 11 months ago · Source ↗
Consumer Confidence Rule — Other violation
medium severityResolvedConsumer Confidence Rule Other violation (Resolved).
EPA SDWIS · Other · Began Jul 1, 2025 · 11 months ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Apr 1, 2025 · 1 year ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Jan 1, 2025 · 1 year ago · Source ↗
Total Haloacetic Acids (HAA5) — MR violation
medium severityArchivedTotal Haloacetic Acids (HAA5) MR violation (Archived).
EPA SDWIS · MR · Began Jan 1, 2025 · 1 year ago · Source ↗
TTHM — MR violation
medium severityArchivedTTHM MR violation (Archived).
EPA SDWIS · MR · Began Jan 1, 2025 · 1 year ago · Source ↗
Lead and Copper Rule — MR violation
medium severityUnaddressedLead and Copper Rule MR violation (Unaddressed).
EPA SDWIS · MR · Began Dec 30, 2024 · 1 year ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Oct 1, 2024 · 1 year ago · Source ↗
Revised Total Coliform Rule — MON violation
medium severityResolvedRevised Total Coliform Rule MON violation (Resolved).
EPA SDWIS · MON · Began Sep 1, 2024 · 1 year ago · Source ↗
Consumer Confidence Rule — Other violation
medium severityUnaddressedConsumer Confidence Rule Other violation (Unaddressed).
EPA SDWIS · Other · Began Jul 1, 2024 · 1 year ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Jul 1, 2024 · 1 year ago · Source ↗
Revised Total Coliform Rule — MON violation
medium severityResolvedRevised Total Coliform Rule MON violation (Resolved).
EPA SDWIS · MON · Began Jun 1, 2024 · 2 years ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Apr 1, 2024 · 2 years ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Jan 1, 2024 · 2 years ago · Source ↗
Nitrate-Nitrite — MR violation
medium severityResolvedNitrate-Nitrite MR violation (Resolved).
EPA SDWIS · MR · Began Oct 1, 2023 · 2 years ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Oct 1, 2023 · 2 years ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Jul 1, 2023 · 2 years ago · Source ↗
Nitrate-Nitrite — MCL violation
high severityHealth-basedArchivedNitrate-Nitrite MCL violation (Archived).
EPA SDWIS · MCL · Began Apr 1, 2023 · 3 years ago · Source ↗
Water-related lawsuits
No lawsuits on record.
In the news & sources
No coverage linked yet.