Onalaska, Wisconsin: Is the Tap Water Safe to Drink?
2026 EPA water quality data for 19 community water systems serving 20,454+ residents. See violations, PFAS results, lead test results, and safety grades — free.
Is Onalaska Tap Water Safe to Drink?
Onalaska has 19 community water systems. 18 of 19 graded systems meet all EPA standards (grade A or B), while 1 has recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.
Onalaska Water Quality Overview
Onalaska, Wisconsin is served by 19 community water systems providing water to approximately 20,454 residents. These systems draw from groundwater sources. Onalaska water systems have recorded 4 health-based violations in their history, though none are currently active. Including monitoring and reporting violations, there are 26 total violations on record.
Find Your Water System
Search by ZIP code to find your exact water provider and see its full EPA report.
All 19 water systems in Onalaska
Looking for water quality data across the whole state? See our full Wisconsin tap water safety report covering Wisconsin’s EPA-regulated water systems.
Onalaska Drinking Water: Frequently Asked Questions
Is Onalaska, Wisconsin tap water safe to drink?
Onalaska has 19 community water systems. 18 of 19 graded systems meet all EPA standards (grade A or B), while 1 has recorded violations. No active health-based violations are currently open. Check individual system reports below for specifics.
How many water utilities serve Onalaska, Wisconsin?
19 community water systems serve Onalaska, Wisconsin, providing water to approximately 20,454 people. Different neighborhoods may be served by different utilities. Enter your ZIP code at the top to find your specific provider.
Does Onalaska tap water have lead?
Lead in drinking water typically enters from old pipes and fixtures inside homes and buildings, not from the treatment plant. The EPA requires water systems to monitor for lead under the Lead and Copper Rule. Click any water system above to see its most recent 90th-percentile lead test results. Homes built before 1986 are most likely to have lead plumbing components.
What contaminants have been found in Onalaska drinking water?
EPA violation records for Onalaska water systems are listed on each utility's report page. Common regulated contaminants include disinfection byproducts (TTHMs, HAA5), coliform bacteria, nitrates, and lead. Click any utility above to see its full violation history going back 10 years.
How do I find out which water company serves my address in Onalaska?
Enter your Onalaska ZIP code in the search box at the top of this page. ClearWater will identify the specific water system serving your area and show you its EPA violation history, lead test results, and an overall safety grade. You can also check your water bill or your utility's annual Consumer Confidence Report (CCR).