A84/100
Hamilton Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 159,428 residents · Ohio
What's In Hamilton's Tap Water?
77
Contaminants Tested
1
Exceed EPA Limits
1
Above EPA Goals
2 contaminants above EPA health goals
| Contaminant | Detected | Limit (MCL) | Status |
|---|---|---|---|
Copper (90th percentile) | 12.10 mg/L | 1.30 mg/L | Over Limit |
1,4-dioxane | 0.410 µg/L | — | Above Goal |
EPA Violation History
3
Violations (last 5yr)
0
Unresolved
0
Health-Related
TIER 3Resolved
Disinfection byproduct treatment technique failure
When: August 14, 2024 – December 31, 2024Rule: Ground Water RuleEnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: April 1, 2023 – June 30, 2023Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
TIER 3Resolved
Failed Level 2 Assessment under Revised Total Coliform Rule
This is a paperwork/process violation — it does not mean a contaminant was detected at unsafe levels.
When: October 1, 2021 – December 31, 2021Rule: Stage 2 DBPREnforcement: Resolving — corrective action underway
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
BUTLER CO. WATER DISTRICT 2 PWS
Population Served
116,572
Water Source
Purchased Surface Water
System ID
OH0900303
SOUTHWEST REGIONAL WATER DISTRICT
Population Served
42,856
Water Source
Groundwater
System ID
OH0903912
Frequently Asked Questions About Hamilton Water
Is Hamilton tap water safe to drink?
Hamilton, Ohio tap water receives a grade of A (84/100), which is considered excellent. Out of 77 contaminants tested, 1 exceed EPA maximum contaminant levels (MCLs) and 3 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 Hamilton's water?
Of the 77 contaminants tested in Hamilton's water supply, the most notable include Copper (90th percentile), Lead (90th percentile), 1,4-dioxane. 1 contaminant(s) exceed EPA legal limits (MCLs). 3 contaminant(s) exceed EPA health goals (MCLGs), which are non-enforceable targets set at levels with no known health risk.
Does Hamilton have any water quality violations?
Yes, Hamilton has 7 EPA violation(s) on record, with the most recent in 2024. Violation types include Other, MR, MCL. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Hamilton?
Based on EPA data, using a water filter in Hamilton 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 Hamilton's tap water come from?
Hamilton's drinking water is sourced from purchased surface water and supplied by BUTLER CO. WATER DISTRICT 2 PWS and 1 other water system(s). The system serves approximately 159,428 people. Surface water sources include rivers, lakes, and reservoirs.
How often is Hamilton'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. Hamilton'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 Hamilton's water compare to other cities in Ohio?
Hamilton's water quality score of 84/100 earns a grade of A, which is considered excellent. This places Hamilton among the better-performing water systems in Ohio. Visit our Ohio state page to see how all cities in the state compare.
What should I do if I'm concerned about Hamilton's water quality?
If you have concerns about Hamilton'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 (BUTLER CO. WATER DISTRICT 2 PWS) 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.