WA / Onalaska
WA · Tap water records
Onalaska tap water, in plain English
Here is what the EPA's own data shows about tap water in Onalaska. According to EPA SDWIS data retrieved June 2026, Onalaska is served by 1 active community water system, together reported to serve about 1,983 people.
As of June 2026, EPA records show 16 violations across the community water system(s) serving Onalaska, going back to the earliest EPA record. None were health-based; the records are monitoring or reporting violations (a required test or report was late or missed). Each is listed by system below, with its status.
What the EPA has on record, by system
Lewis Co Water Dist #2
1,983 served · groundwater · PWSID WA5347001 - Monitoring Revised Total Coliform Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in November 2016. All have since returned to compliance, per EPA records.
- Monitoring Consumer Confidence Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 6 times between July 2010 and July 2016. All have since returned to compliance, per EPA records.
- Monitoring TTHM: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2014 and January 2016. All have since returned to compliance, per EPA records.
- Monitoring Total Haloacetic Acids (HAA5): a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 3 times between January 2014 and January 2016. All have since returned to compliance, per EPA records.
- Monitoring Nitrate: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded once in January 2015. All have since returned to compliance, per EPA records.
- Monitoring Lead and Copper Rule: a monitoring or reporting violation (a required test or report was late or missed — not a measured exceedance), recorded 2 times between January 2004 and January 2008. All have since returned to compliance, per EPA records.
What this means
A health-based violation means a contaminant was recorded above the limit the EPA tracks for it. A monitoring or reporting violation means a required test or report was late or missed — not that a contaminant was measured above a limit. “Returned to compliance” means the EPA recorded the issue as resolved.
This page summarizes the EPA's own records and does not assess whether your water is safe to drink. For the most current details, you can verify every record directly with the EPA, and contact your water system with questions.
Source: U.S. EPA Envirofacts SDWIS, retrieved June 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.