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

Home hazard report for 52361 — Williamsburg, IA

ZIP 52361 is served by Williamsburg Public Water Supply: no health-based violations since 2016, latest lead result 3 ppb, PFAS not tested. Iowa County is in EPA radon zone 1.

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Where ZIP 52361 is

Dashed: ZIP area · blue: utility service area · scroll or pinch to zoom
ZIP code areaZIP center 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.

Drinking water: Williamsburg Public Water Supply

EPA IDIA4884023
People served3,345
Sourcegroundwater (wells)
Connections1,332

Health-based violations

No health-based violations reported since 2016.

Full record for Williamsburg Public Water Supply →

Lead

Jan 20243 ppb
Jan 20232 ppb
Jul 20223.7 ppb
Jan 20222.9 ppb
Jan 20212.5 ppb
Jul 20204 ppb
Jan 20206.6 ppb
Jul 201918.3 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 (“forever chemicals”)

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

Radon in Iowa County

EPA radon zone 1 — highest potential. Predicted average indoor radon above 4 pCi/L — EPA’s action level. Test your home.

Radon is a colorless, odorless radioactive gas from soil and rock, and the leading cause of lung cancer among non-smokers. EPA recommends fixing a home at 4 pCi/L or above and considering it from 2 pCi/L. A short-term test kit costs about $15–30. How radon zones work →

Natural hazard risk

FEMA rates the overall natural-hazard risk of this neighborhood (census tract) as Relatively Moderate, with relatively high social vulnerability and very high community resilience.

Strong windVery High
TornadoVery High
HailRelatively High
Riverine floodingRelatively High
Winter weatherRelatively High
Cold waveRelatively Moderate
DroughtRelatively Moderate
Heat waveRelatively Moderate
Ice stormRelatively Moderate
LightningRelatively Moderate
WildfireRelatively Moderate
LandslideRelatively Low
EarthquakeVery Low
HurricaneVery Low

FEMA National Risk Index (December 2025): expected annual losses from each hazard combined with social vulnerability and community resilience, rated relative to all U.S. census tracts. Hazards not listed are not applicable here. It describes the area, not a single building; flood insurance maps (FEMA FIRMs) decide flood-insurance requirements.

Live conditions: river gauges and flood levels · tornado warnings · wildfire detections · earthquakes — our sister maps, updated from NOAA, USGS and NASA every few minutes.

Superfund sites nearby

No site on EPA’s Superfund National Priorities List lies within 10 miles of the center of this ZIP code.

EPA Superfund National Priorities List (NPL): the country’s most serious known hazardous-waste sites, each with an EPA cleanup record (linked). Distance is measured from the ZIP center to the site’s reference point; being near a site does not by itself mean exposure — EPA site pages describe what was found and how it is being cleaned up.

Buying a home in Williamsburg? See the 2026 conforming, FHA and jumbo loan limits for Iowa County →

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 about 52361

Who supplies drinking water to ZIP 52361?

Williamsburg Public Water Supply (EPA ID IA4884023), a groundwater (wells) system serving about 3,345 people.

Is there lead in Williamsburg, IA tap water?

The utility’s latest 90th-percentile lead result (Jan 2024) was 3 ppb; EPA’s action level is 15 ppb, falling to 10 ppb from 2027. Lead mostly comes from service lines and home plumbing, so the only way to know your tap is to test it.

Does Williamsburg, IA water have PFAS?

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).

Has the water system in 52361 had violations?

No health-based violations reported since 2016.

What natural hazards affect ZIP 52361?

FEMA’s National Risk Index rates the overall natural-hazard risk here as Relatively Moderate; the highest-rated hazards are strong wind (very high), tornado (very high), hail (relatively high).

Are there Superfund sites near 52361?

No active Superfund site within 10 miles of the ZIP center.

Is radon a problem in Iowa County?

Iowa County is in EPA radon zone 1 (highest potential). Predicted average indoor radon above 4 pCi/L — EPA’s action level. Test your home.