A82/100
Dillon Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 4,300 residents · Montana
What's In Dillon's Tap Water?
32
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 2.02 mg/L | 1.30 mg/L | Over Limit |
Lead (90th percentile) | 0.003 mg/L | 0.015 mg/L | Above Goal |
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2012.
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
DILLON CITY OF
Population Served
4,300
Water Source
Groundwater
System ID
MT0000201
Frequently Asked Questions About Dillon Water
Is Dillon tap water safe to drink?
Dillon, Montana tap water receives a grade of A (82/100), which is considered excellent. Out of 32 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 2 exceed health guidelines (MCLGs). While the water meets federal standards, some residents may still choose to use a filter for additional peace of mind.
What contaminants are in Dillon's water?
Of the 32 contaminants tested in Dillon's water supply, the most notable include Copper (90th percentile), Lead (90th percentile). 1 contaminant(s) exceed EPA legal limits (MCLs). 2 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Dillon have any water quality violations?
Yes, Dillon has 7 EPA violation(s) on record, with the most recent in 2012. Violation types include MR. None of these are classified as health-based violations.
Do I need a water filter in Dillon?
Based on EPA data, using a water filter in Dillon is recommended. 1 contaminant(s) exceed legal limits. An NSF-certified filter — such as a reverse osmosis or activated carbon system — can effectively reduce many common contaminants. Choose a filter certified to remove the specific contaminants found in your area.
Where does Dillon's tap water come from?
Dillon's drinking water is sourced from groundwater and supplied by DILLON CITY OF. The system serves approximately 4,300 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Dillon'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. Dillon'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 Dillon's water compare to other cities in Montana?
Dillon's water quality score of 82/100 earns a grade of A, which is considered excellent. This places Dillon among the better-performing water systems in Montana. Visit our Montana state page to see how all cities in the state compare.
What should I do if I'm concerned about Dillon's water quality?
If you have concerns about Dillon'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 (DILLON CITY OF) 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.