Saint Leonard, MD: High Radon Risk — 40/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Monitoring data across Saint Leonard reveals a persistent pattern of below-average compliance in MD — multiple service areas carry documented health violations, and the data has shown little overall improvement over recent EPA reporting cycles.
How Saint Leonard Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Saint Leonard Water
- Homes built before 1986: 48% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 12.39 — above typical levels.
Who Supplies Your Water in Saint Leonard
Saint Leonard, MD is covered by 2 major water utilities out of 2 federally tracked systems, each managing its own pipes, treatment processes, and EPA filings. What a household gets from the tap depends on which provider's system serves that address.
Overview
We track water quality and home safety data for 1 ZIP code in Saint Leonard, Maryland, covering 2 community water systems serving approximately 6,481 people.
No EPA violations recorded across any ZIP codes in Saint Leonard — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Saint Leonard: D (40/100)
The score combines three factors:
| Factor | What It Measures |
|---|---|
| Water Quality | EPA violations and compliance history |
| Lead Levels | 90th percentile lead concentration vs EPA action level |
| Radon Risk | EPA radon zone classification |
Water Sources
Saint Leonard water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Saint Leonard
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 1 (High Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 20685 | D | SCIENTISTS CLIFFS | 1,425 |
All ZIP Codes in Saint Leonard
- 20685 [D]
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Lead/copper: EPA Lead and Copper Rule sampling data
- Radon: EPA Map of Radon Zones
Updated daily.
Health Outcomes in Saint Leonard
Source: CDC PLACES (County-level estimates). Water contamination can correlate with respiratory and chronic health conditions.
Compared to National Average
Vertical line = national average. ■ Above national · ■ Below national
Housing & Infrastructure in Saint Leonard
With 48% of homes built before 1986, lead solder in plumbing is a potential concern. The EPA banned lead solder in 1986, but many older homes retain original plumbing.
Source: U.S. Census Bureau American Community Survey (ACS).
Housing Age Profile
With a median build year of 1983, Saint Leonard's housing stock reflects a city built across multiple eras. A substantial share of homes predate 1986 — the year lead solder in plumbing was federally banned — meaning the risk from plumbing materials is unevenly distributed across the city's neighborhoods and property types.
Most homes in Saint Leonard were built after 1986, reducing the risk of lead contamination from plumbing. Older homes should still be tested.
Source: U.S. Census Bureau ACS B25034.
Cost Context: What Remediation Means for Saint Leonard Homeowners
Equity impact data for Saint Leonard lands in the favorable tier — remediation claims a small slice of what properties here are worth.
Remediation costs in Saint Leonard are relatively low compared to home values. The $1,600–$3,300 estimated range is a small fraction of median property value. Home values are 1% above the Maryland average.
Lead Exposure Risk for Children in Saint Leonard
Why children are most at risk: The CDC states there is no safe level of lead exposure for children. Children under 6 absorb lead more readily than adults, and even low levels can cause developmental delays, learning difficulties, and behavioral problems.
When older housing represents 48% of the local inventory or aggregate readings approach the federal action level, an in-home check becomes the standard way to translate citywide averages into the specific reality of an individual Saint Leonard address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Saint Leonard
Over the multi-decade window covered by the National Flood Insurance Program, Saint Leonard has accumulated 51 claims — a total that suggests more than isolated flood exposure. With 100% of ZIP codes in designated flood zones, the water-quality implications of flooding move from hypothetical to periodically relevant: treatment intake can be compromised, wells can be infiltrated, and distribution backflow can occur.
Saint Leonard has a moderate flood history with 51 FEMA claims averaging $15,411 per payout. 100% of ZIP codes fall within FEMA flood zones. Flood events can contaminate drinking water and overwhelm treatment systems.
How flooding affects water quality: Flood events can introduce sewage, agricultural runoff, and industrial chemicals into water supplies. Even after floodwaters recede, contamination can persist in wells and aging infrastructure. Flood damage can add significantly to the estimated <strong>$2,400</strong> remediation cost per household.
Residents in flood-prone areas should consider flood insurance even outside FEMA zones — over 25% of flood claims come from low-to-moderate risk areas. After any flood event, test your water before drinking.
Source: FEMA National Flood Insurance Program (NFIP) claims data, FEMA flood zone designations.
What You Can Do in Saint Leonard
- Test your water at home. City-level data shows averages — your tap may differ. NSF-certified test kits cost $20-40 and give results in days.
- Install a certified water filter. An NSF-certified pitcher or under-sink filter removes most common contaminants.
- Check your home's plumbing. With 48% of homes built before 1986, lead solder is a real possibility.
- Review your water system's CCR. Your utility publishes an annual Consumer Confidence Report with detailed test results. Request it or find it online.
Deep Dive Reports
Detailed analysis for Saint Leonard, MD