EPA data as of Oct 2026 · page updated 2026-10-29

Home hazard report for 20650 — Leonardtown, MD

ZIP 20650 is served by Breton Bay: no health-based violations since 2016, latest lead result 0 ppb, PFAS not tested. St. Mary's County is in EPA radon zone 2.

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Where ZIP 20650 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: Breton Bay

EPA IDMD0180001
People served1,012
Sourcegroundwater (wells)
Connections372

Health-based violations

No health-based violations reported since 2016.

Full record for Breton Bay →

Lead

Jan 20220 ppb
Jan 20210 ppb
Jan 20150 ppb
Jan 20120 ppb
Jan 20093 ppb
Jan 20060 ppb
Jan 20032 ppb
Jan 20000 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 St. Mary's County

EPA radon zone 2 — moderate potential. Predicted average indoor radon between 2 and 4 pCi/L. Test your home; many homes here exceed 4 pCi/L.

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 Low, with relatively low social vulnerability and very high community resilience.

Strong windRelatively High
Coastal floodingRelatively Moderate
DroughtRelatively Moderate
Heat waveRelatively Moderate
HurricaneRelatively Moderate
Ice stormRelatively Moderate
LightningRelatively Moderate
TornadoRelatively Moderate
Winter weatherRelatively Moderate
Cold waveRelatively Low
EarthquakeRelatively Low
HailRelatively Low
LandslideRelatively Low
Riverine floodingRelatively Low
WildfireRelatively 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

SiteStatusDistance
Southern Maryland Wood Treating
Hollywood, Maryland · EPA ID MDD980704852
Cleaned up & deleted7.2 mi

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.

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 20650

Who supplies drinking water to ZIP 20650?

Breton Bay (EPA ID MD0180001), a groundwater (wells) system serving about 1,012 people.

Is there lead in Leonardtown, MD tap water?

The utility’s latest 90th-percentile lead result (Jan 2022) was 0 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 Leonardtown, MD 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 20650 had violations?

No health-based violations reported since 2016.

What natural hazards affect ZIP 20650?

FEMA’s National Risk Index rates the overall natural-hazard risk here as Relatively Low; the highest-rated hazards are strong wind (relatively high), coastal flooding (relatively moderate), drought (relatively moderate).

Are there Superfund sites near 20650?

No active Superfund site within 10 miles of the ZIP center. Sites within 10 miles: Southern Maryland Wood Treating (7.2 mi, Cleaned up & deleted).

Is radon a problem in St. Mary's County?

St. Mary's County is in EPA radon zone 2 (moderate potential). Predicted average indoor radon between 2 and 4 pCi/L. Test your home; many homes here exceed 4 pCi/L.