F4/100
Thief River Falls Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 8,701 residents · Minnesota
What's In Thief River Falls's Tap Water?
31
Contaminants Tested
0
Exceed EPA Limits
1
Above EPA Goals
1 contaminant above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Lead (90th percentile) | 0.007 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
1
Violation (last 5yr)
1
Unresolved
1
Health-Related
TIER 1 — URGENTUnresolved
Violation related to Nitrate
When: January 1, 2025 – January 31, 2025Rule: Surface Water Treatment RuleEnforcement: Informal — resolved cooperativelyVerify on EPA.gov
Understanding violation severity
Tier 1Urgent health risk. Utility must notify all customers within 24 hours.Tier 2Important health or treatment issue. Customers notified within 30 days.Tier 3Administrative or monitoring issue. Reported in the annual water quality report.
Source: EPA Safe Drinking Water Information System (SDWIS) · Updated quarterly
Water Utility Details
Thief River Falls
Population Served
8,701
Water Source
Surface Water
System ID
MN1570003
Frequently Asked Questions About Thief River Falls Water
Is Thief River Falls tap water safe to drink?
Thief River Falls, Minnesota tap water receives a grade of F (4/100), which is considered failing. 0 contaminant(s) exceed EPA maximum contaminant levels and 21 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Thief River Falls's water?
Of the 31 contaminants tested in Thief River Falls's water supply, the most notable include Lead (90th percentile). No contaminants exceed EPA legal limits. 1 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Thief River Falls have any water quality violations?
Yes, Thief River Falls has 21 EPA violation(s) on record, with the most recent in 2025. Violation types include TT, MR. 18 of these are health-based violations, which are the most serious category.
Do I need a water filter in Thief River Falls?
Thief River Falls water meets EPA standards, so a filter is not strictly necessary. However, some residents prefer the added security of a water filter. EPA health goals (MCLGs) are stricter than legal limits and are set at levels with zero expected health risk. 1 contaminant(s) exceed these stricter goals.
Where does Thief River Falls's tap water come from?
Thief River Falls's drinking water is sourced from surface water and supplied by Thief River Falls. The system serves approximately 8,701 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Thief River Falls's water tested?
Under the Safe Drinking Water Act (SDWA), water utilities are required to regularly test for over 90 contaminants. Testing frequency varies by contaminant — some are tested monthly, others quarterly or annually. Thief River Falls's water systems must report results to the EPA and publish an annual Consumer Confidence Report (CCR). The data on this page reflects the latest available EPA testing data.
How does Thief River Falls's water compare to other cities in Minnesota?
Thief River Falls's water quality score of 4/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Minnesota state page to see how all cities in the state compare.
What should I do if I'm concerned about Thief River Falls's water quality?
If you have concerns about Thief River Falls's tap water, consider these steps: (1) Request your utility's annual Consumer Confidence Report for detailed local data. (2) Get your water independently tested through a state-certified laboratory. (3) Consider an NSF-certified water filter rated for the contaminants found in your area. (4) Contact your water utility (Thief River Falls) with specific questions. (5) Report water quality issues to your state drinking water program or the EPA Safe Drinking Water Hotline at 800-426-4791.