EPA data as of Oct 2026 · page updated 2026-10-30

Crystal Lake Water Supply

Crystal Lake Water Supply (EPA ID IA4115092) in Thompson, IA supplies groundwater (wells) to about 255 people: 1 violation since 2016, latest lead result 0 ppb, PFAS not tested.

Service area

EPA service-area boundary (state-supplied or EPA-modeled)
Water utility service area PFOA/PFOS ≥ 4 ppt Lead > 15 ppb 5+ violations Superfund site (active) proposed cleaned up Circles: other water systems flagged nearby; size = people served. Tap any symbol for details.

System facts

People served255
Connections147
Sourcegroundwater (wells)
WholesalerNo

Health-based violations

Contaminant or ruleHealth-based violations since 2016
Nitrite1

A health-based violation means a contaminant exceeded its legal limit (MCL) or a required treatment technique was not met, as reported by the state to EPA’s SDWIS. All are listed as resolved or archived; the latest began Oct 2022.

Lead

Jan 20230 ppb
Jan 20220 ppb
Jan 20210 ppb
Jan 20200 ppb
Jul 20191 ppb
Jan 20192 ppb
Jul 20182 ppb
Jan 201810 ppb

90th-percentile lead per sampling round (90% of the homes sampled were at or below this level). Black line: EPA’s 15 ppb action level; under the Lead and Copper Rule Improvements the action level becomes 10 ppb from 2027.

PFAS

This system was not part of EPA’s 2023–2025 nationwide PFAS testing (UCMR 5).

ZIP codes served

ZIP codes whose center lies in this system’s service area.

What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.

Questions

Has Crystal Lake Water Supply had drinking water violations?

Health-based violations since 2016: Nitrite. All are listed as resolved.

What is the lead level in Crystal Lake Water Supply water?

The latest 90th-percentile lead result (Jan 2023) was 0 ppb. EPA’s action level is 15 ppb (10 ppb from 2027).

Does Crystal Lake Water Supply have PFAS in its water?

This system was not part of EPA’s 2023–2025 nationwide PFAS testing (UCMR 5 covers systems serving over 3,300 people and a sample of smaller ones).