St. Mary's County, Maryland
28 ZIP codes · Home Safety Score unavailable · 0 of 28 tracked ZIP records scored · Updated
Data: ZipCheckup Home Safety Score model 4.0.0; EPA SDWIS, UCMR 5, EPA radon zones, EPA AirData Last verified:
ZIP Code Risk Map
Water Quality Map: St. Mary's County, Maryland
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.5 (asthma 10.7%, diabetes 11.4%)
Estimated additional annual cost per homeowner: $2,959, driven primarily by sea_level
52.9% of homes built before 1978 (lead paint era)
Violation History (2023–2024)
→ Stable trendEPA violation counts by year across St. Mary's County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 10 violations. Past 5 years: 12 total (12 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
Infrastructure Overview
Modeled area-level indicator, not a failure probability. Sources: Census ACS housing age, EPA DWINS infrastructure needs, EPA SDWIS violations, and EPA lead indicators.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $2,959
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
45,306 housing units in St. Mary's County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in St. Mary's County
Remediation costs are relatively manageable for most homeowners in St. Mary's County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Health Outcomes vs National Average
CDC PLACES data for St. Mary's County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving St. Mary's County
8 community water systems serving St. Mary's County.
Show all 8 water systems
19 total water systems serve St. Mary's County.
Systems with the most violations in St. Mary's County
5 water systems with recorded EPA violations.
All ZIP Codes in St. Mary's County
28 ZIP codes tracked in St. Mary's County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 20606 | Abell | — | — | $464K | |
| 2 | 20609 | Avenue | — | — | $475K | |
| 3 | 20618 | Bushwood | — | — | $292K | |
| 4 | 20619 | California | — | — | 12 (1 health) | $364K |
| 5 | 20620 | Callaway | — | — | 1 | $369K |
| 6 | 20621 | Chaptico | — | — | 4 | $563K |
| 7 | 20624 | Clements | — | — | 3 | $424K |
| 8 | 20626 | Coltons Point | — | — | — | |
| 9 | 20627 | Compton | — | — | — | |
| 10 | 20628 | Dameron | — | — | $412K | |
| 11 | 20630 | Drayden | — | — | 1 | $585K |
| 12 | 20634 | Great Mills | — | — | 9 (1 health) | $335K |
| 13 | 20635 | Helen | — | — | — | |
| 14 | 20636 | Hollywood | — | — | 11 | $470K |
| 15 | 20650 | Leonardtown | — | — | 13 | $464K |
| 16 | 20653 | Lexington Park | — | — | 19 (3 health) | $342K |
| 17 | 20656 | Loveville | — | — | 2 | — |
| 18 | 20659 | Mechanicsville | — | — | 11 | $388K |
| 19 | 20660 | Morganza | — | — | — | |
| 20 | 20667 | Park Hall | — | — | 5 | — |
| 21 | 20670 | Patuxent River | — | — | 7 | — |
| 22 | 20674 | Piney Point | — | — | $399K | |
| 23 | 20680 | Ridge | — | — | $392K | |
| 24 | 20684 | Saint Inigoes | — | — | $376K | |
| 25 | 20686 | Saint Marys City | — | — | — | |
| 26 | 20687 | Scotland | — | — | $772K | |
| 27 | 20690 | Tall Timbers | — | — | $559K | |
| 28 | 20692 | Valley Lee | — | — | 2 | $382K |
Recommended Buyer Guides for St. Mary's County
Editorial-only picks, screened against the EPA detections on file.
- Best Lead Paint Test Kits — 52.9% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for St. Mary's County, Maryland
Overview
St. Mary's County in Maryland covers 28 tracked ZIP records. No Home Safety Score is published because the required model evidence is incomplete for every tracked record; missing evidence is not treated as zero.
14 of 14 ZIP codes with a reported violation count in the available EPA record have recorded EPA violations. 3 health-based violations appear in the available health breakdown.
← Back to Maryland Home Safety Profile
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- PFAS screening: EPA UCMR 5
- Radon zones: EPA Map of Radon Zones
- Air quality: EPA AirData annual AQI
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Reporting periods vary by source. Missing data is shown as unavailable, not as zero.