TapWaterMap

IA / Thompson

IA · Tap water records

Thompson tap water, in plain English

Here is what the EPA's own data shows about tap water in Thompson. According to EPA SDWIS data retrieved October 2026, Thompson is served by 3 active community water systems, together reported to serve about 1,003 people.

As of October 2026, EPA records show 4 violations across the community water system(s) serving Thompson, going back to the earliest EPA record. 1 of these are classified by the EPA as health-based (a contaminant recorded above the limit the EPA tracks); the rest are monitoring or reporting violations. Each is listed by system below, with its status.

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What the EPA has on record, by system

Thompson Water Works

499 served · groundwater · PWSID IA9585017

Crystal Lake Water Supply

255 served · groundwater · PWSID IA4115092

Leland Water Supply

249 served · groundwater · PWSID IA9549073

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 October 2026. Records cover the EPA's full reporting history for these systems. Verify at EPA ECHO.