Cobb Island, MD Water Safety: 55/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
The systems supplying Cobb Island vary in performance across MD benchmarks — most meet minimum federal standards, but documented violations in select areas are on record.
How Cobb Island Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Cobb Island Water
- Homes built before 1986: 70% — older plumbing may contain lead solder.
- Estimated remediation: $1,600 per household.
- CDC health risk index: 13.16 — above typical levels.
Who Supplies Your Water in Cobb Island
Water supply in Cobb Island, MD follows a divided structure: 2 utilities account for the largest share of residential service out of 2 total systems, each managing its own distribution network and EPA reporting. Because these systems operate independently, rate decisions and compliance outcomes are determined separately.
Overview
We track water quality and home safety data for 1 ZIP code in Cobb Island, Maryland, covering 2 community water systems serving approximately 1,135 people.
No EPA violations recorded across any ZIP codes in Cobb Island — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Cobb Island: C (55/100)
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
Cobb Island water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Cobb Island
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate 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 |
|---|---|---|---|
| 20625 | C | Swan Point | 945 |
All ZIP Codes in Cobb Island
- 20625 [C]
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 Cobb Island
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 Cobb Island
With 70% 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
While newer cities carry lower aggregate plumbing risk from lead-era construction, Cobb Island sits firmly in the older category. The median build year of 1949 indicates that more than half the housing stock was built before 1986, when lead solder was still legally used in residential copper plumbing — and a substantial portion likely predates 1970, when lead pipes were still commonly installed for service lines. These two thresholds together define the elevated plumbing risk environment that older housing cities carry, independent of what the municipal water supply delivers to the meter.
Over half of homes in Cobb Island 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.
Cost Context: What Remediation Means for Cobb Island Homeowners
In Cobb Island, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Cobb Island are relatively low compared to home values. The $800–$2,600 estimated range is a small fraction of median property value. Home values are 43% below the Maryland average.
Lead Exposure Risk for Children in Cobb Island
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.
Wherever 70% of local housing was built before solder rules changed — as is the case in Cobb Island — a faucet-level sample closes the gap that aggregate utility data cannot.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Cobb Island
Cobb Island's flood exposure sits in the moderate range: 21 NFIP claims on record and 100% of ZIP codes within FEMA-designated flood zones. Residents with private wells or older infrastructure have reasonable grounds to factor flood timing into their water quality awareness.
Cobb Island has a moderate flood history with 21 FEMA claims averaging $18,614 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>$1,600</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 Cobb Island
- 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 70% of homes built before 1986, lead solder is a real possibility.
Deep Dive Reports
Detailed analysis for Cobb Island, MD