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Public water system record

City of Great Falls

Serves Great Falls, Cascade County, MT · 60,000 people served

Federal records show 5 health-based violations and no monitoring/reporting issues for City of Great Falls in the last ten years. The most serious issue in this window was a resolved Haloacetic Acids (HAA5) violation.

  • MT0000525
  • GREAT FALLS
  • MT
  • 60,000 served

System profile

Source water Surface water
ZIP 59403
EPA system ID MT0000525

Verify this system on EPA ECHO →

Health-based violations, last 10 years
5
Resolved
5
Unresolved
0
Any acute record
No
Monitoring issues, last 10 years
0

Key facts

  • City of Great Falls draws water from 2 surface water intakes.
  • Highest measured level in the last 10 years: Haloacetic Acids (HAA5), 74.8 µg/L, federal limit 60 µg/L (1.2 times the limit), 2018.
  • Record on file since 1997, with 1 health-based violation before October 19, 2016.
  • Lead pipe inventory: 156 lead and 5,383 unknown out of 22,210 service lines.

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

Contaminant Rule family Start date Status Acute
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 61 µg/L, federal limit 60 µg/L (at or just above the limit)
 220 Apr 1, 2019 Resolved No
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 72.5 µg/L, federal limit 60 µg/L (1.2 times the limit)
 220 Jan 1, 2019 Resolved No
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 74.8 µg/L, federal limit 60 µg/L (1.2 times the limit)
 220 Oct 1, 2018 Resolved No
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 73.8 µg/L, federal limit 60 µg/L (1.2 times the limit)
 220 Jul 1, 2018 Resolved No
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 60.5 µg/L, federal limit 60 µg/L (at or just above the limit)
 220 Apr 1, 2018 Resolved No

Full record since 1997

EPA's records for City of Great Falls go back to 1997. Before October 19, 2016 they list 1 health-based violation (1 resolved) and 3 monitoring or reporting violations.

Violations that began in Health-based Monitoring and reporting
1990s 1 0
2000s 0 3
October 19, 2016 to 2019 5 0

Most recent health-based violation before October 19, 2016: Surface Water Treatment Rule, began August 1997, Resolved.

Show the health-based violation before October 19, 2016
Contaminant Start date Status
Surface Water Treatment Rule
Treatment technique failure
 Aug 1, 1997 Resolved

What the violations mean

Haloacetic Acids (HAA5)

5 incidents

Haloacetic acid byproducts exceeded the federal limit

Long-term exposure to HAAs may increase cancer risk

Where the water comes from

City of Great Falls draws water from 2 surface water intakes. 17 other community water systems and 12 smaller public systems such as schools, businesses or campgrounds buy water from City of Great Falls.

Community systems that buy water from it

Annual water quality report

City of Great Falls must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Montana.

Certified drinking water labs by state EPA guidance for private wells