F0/100
Onalaska Tap Water Quality: Is It Safe to Drink? (2026 Report)
Serving 1,983 residents · Washington
What's In Onalaska's Tap Water?
1
Contaminants Tested
0
Exceed EPA Limits
0
Above EPA Goals
EPA Violation History
No violations in the past 5 years
Full EPA compliance since 2016.
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
LEWIS CO WATER DIST #2
Population Served
1,983
Water Source
Groundwater
System ID
WA5347001
Frequently Asked Questions About Onalaska Water
Is Onalaska tap water safe to drink?
Onalaska, Washington tap water receives a grade of F (0/100), which is considered failing. 0 contaminant(s) exceed EPA maximum contaminant levels and 515 violation(s) are on record. Residents should consider using an NSF-certified water filter to reduce contaminant exposure.
What contaminants are in Onalaska's water?
1 contaminants were tested in Onalaska's water supply. No contaminants exceed EPA legal limits (MCLs) or health goals (MCLGs), which is a positive indicator of water quality.
Does Onalaska have any water quality violations?
Yes, Onalaska has 515 EPA violation(s) on record, with the most recent in 2016. Violation types include MON, Other, MR. 2 of these are health-based violations, which are the most serious category.
Do I need a water filter in Onalaska?
Onalaska 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. All contaminants are within health goals.
Where does Onalaska's tap water come from?
Onalaska's drinking water is sourced from groundwater and supplied by LEWIS CO WATER DIST #2. The system serves approximately 1,983 people. Groundwater is pumped from underground aquifers, which often provides natural filtration.
How often is Onalaska'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. Onalaska'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 Onalaska's water compare to other cities in Washington?
Onalaska's water quality score of 0/100 earns a grade of F, which is considered failing. This is a concerning score that suggests significant water quality issues. Visit our Washington state page to see how all cities in the state compare.
What should I do if I'm concerned about Onalaska's water quality?
If you have concerns about Onalaska'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 (LEWIS CO WATER DIST #2) 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.