- EPA's UCMR 5 testing looked for 30 contaminants here and found 1.
- Lithium: found in 4 of 4 samples, average 68.9 µg/L, highest 80.8 µg/L (EPA UCMR 5 testing, Mar 2023–Dec 2023)
- Lead, 90th percentile: 12 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2026–Jun 30, 2026). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
Public EPA test results
Can you drink Great Falls tap water? What EPA records show
EPA MT0000525 · serves Great Falls, MT · about 60,000 people (EPA SDWIS)
This report shows EPA's federal records for this water system: UCMR 5 testing, lead testing and violations. It isn't a test of the water at your tap, and it has no Water Score.
Public EPA test results
Great Falls City of (EPA MT0000525)
EPA data as of October 14, 2026. For Great Falls's main utility, Great Falls City of: We found no health-based violations in EPA's records for this system (MT0000525) since July 1, 2021, as of October 14, 2026. PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
What EPA records show for Great Falls City of, as of October 14, 2026
We found no health-based violations in EPA's records for this system (MT0000525) since July 1, 2021, as of October 14, 2026.
Source: EPA ECHO record for Great Falls City of (SDWIS). Data as of October 14, 2026.
Lead, 90th percentile: 12 ppb at the latest result in EPA records for a monitoring period that ran on or after July 1, 2021, at or below EPA's 15 ppb action level (EPA SDWIS, monitoring period Jan 1, 2026–Jun 30, 2026). The 90th percentile is a system-wide measure from homes sampled under EPA's lead rule; it isn't a result for your home.
EPA's UCMR 5 testing looked for 30 contaminants here and found 1.
PFOA and PFOS were not detected at or above EPA's reporting level in EPA's UCMR 5 testing.
Source: EPA records (SDWIS, UCMR 5). SDWIS: data as of Oct 14, 2026. EPA UCMR 5 data, samples through June 2026.
Your water bill names your utility.
Does Great Falls City of use chloramine?
EPA treatment records (state-reported) list chloramines for Great Falls City of. EPA record