Cabin John, MD: High Radon Risk — 45/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Although conditions vary by service area, Cabin John's water systems collectively show below-average compliance within MD — health-based violations are documented throughout the city, and the overall grade reflects a pattern rather than isolated incidents.
How Cabin John Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Cabin John Residents
- Homes built before 1986: 66% — older plumbing may contain lead solder.
- Estimated remediation: $2,900 per household.
- CDC health risk index: 10.24.
Cabin John's Water Providers
2 independent water providers serve Cabin John, MD — 2 systems appear in federal records.
Overview
We track water quality and home safety data for 1 ZIP code in Cabin John, Maryland (population ~1,602), covering 2 community water systems serving approximately 1,900,096 people region-wide.
No EPA violations recorded across any ZIP codes in Cabin John — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Cabin John: D (45/100)
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
Cabin John water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Cabin John
- 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 |
|---|---|---|---|
| 20818 | D | WASHINGTON SUBURBAN SANITARY COMMISSION | 1,900,000 |
All ZIP Codes in Cabin John
- 20818 [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.
Cabin John Community Health Snapshot
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
Cabin John Infrastructure Age
With 66% 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
Lead solder was standard in copper plumbing until federally banned in 1986; lead pipes were common in service lines pre-1970. Cabin John's median build year of 1972 reflects a housing stock where these older materials are a pervasive feature — not a rare legacy — of the residential plumbing landscape.
Over half of homes in Cabin John were built before 1986, when lead solder was banned. Older plumbing may leach lead into drinking water, especially with corrosive water chemistry.
Source: U.S. Census Bureau ACS B25034.
How Remediation Costs Compare in Cabin John
Given current Cabin John valuations, the remediation-to-property-value ratio is low — most homeowners are looking at a proportionally modest share that fits within routine financial planning.
Remediation costs in Cabin John are relatively low compared to home values. The $1,900–$4,100 estimated range is a small fraction of median property value. Home values are 198% above the Maryland average.
Cabin John: Lead Risk & Vulnerable Populations
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.
Even where utility-side monitoring meets Lead and Copper Rule requirements, the 66% pre-rule share in Cabin John keeps interior-plumbing variation as a household-level question that aggregate data cannot resolve.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Cabin John: Flood History & Water Damage Risk
The National Flood Insurance Program captures decades of claims at the local level, building a record of cumulative community flood exposure. For Cabin John, that record documents 13 claims and 100% of ZIP codes inside FEMA-designated flood zones. What makes those numbers relevant to water quality is the set of mechanisms flooding activates: heavy precipitation that floods treatment intake zones can introduce contaminants upstream of normal filtration; well casings in low-lying areas can be infiltrated by floodwaters carrying bacteria, sediment, and chemical residue; and distribution system pressure changes during flooding can create backflow conditions. These effects become more probable as flood frequency and magnitude increase — and the NFIP record indicates both are meaningful factors locally.
Cabin John has a moderate flood history with 13 FEMA claims averaging $12,198 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>$2,900</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 Cabin John
- 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 66% 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 Cabin John, MD