Monrovia, MD: High Radon Risk — 40/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Monrovia, MD water systems: poor compliance record, lower-tier safety grade.
How Monrovia Compares
Data: EPA SDWIS Last verified: 2026-06-03
Monrovia Water: The Quick Version
- Homes built before 1986: 45% — older plumbing may contain lead solder.
- Estimated remediation: $1,700 per household.
- CDC health risk index: 11.57.
Water Systems Serving Monrovia
Federal drinking water records identify 3 systems in Monrovia, MD. The leading 3 providers serve the largest share of residential connections, each operating as a separate entity with its own rate authority, infrastructure management, and EPA compliance obligations — so service conditions are not uniform city-wide.
Overview
We track water quality and home safety data for 1 ZIP code in Monrovia, Maryland (population ~7,815), covering 3 community water systems serving approximately 86,354 people region-wide.
No EPA violations recorded across any ZIP codes in Monrovia — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Monrovia: 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
Monrovia water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Monrovia
- 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 |
|---|---|---|---|
| 21770 | D | New Design - Frederick County | 74,911 |
All ZIP Codes in Monrovia
- 21770 [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.
CDC Health Data for Monrovia
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
How Old Is Monrovia's Housing Stock?
With 45% 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
Two regulatory milestones define plumbing-era risk in residential housing: 1970, when lead pipes were still commonly installed for service lines, and 1986, when lead solder was banned from new copper plumbing. A median build year of 1981 places Monrovia in the middle zone between those thresholds — with a meaningful share of housing predating both cutoffs. The distribution shown above breaks out those eras explicitly, clarifying where concentrated risk sits across the residential inventory.
Most homes in Monrovia 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.
Monrovia: Remediation Cost in Perspective
Remediation costs in Monrovia are small relative to typical property values — the cost-to-value ratio here is favorable.
Remediation costs in Monrovia are relatively low compared to home values. The $1,100–$2,300 estimated range is a small fraction of median property value. Home values are 40% above the Maryland average.
Protecting Children from Lead in Monrovia
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.
Practically, the structural drivers in Monrovia — 45% pre-rule stock and citywide monitoring at or beyond the regulatory benchmark — make an in-home draw the practical way to translate aggregate averages into the specific conditions at one address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
What You Can Do in Monrovia
- 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 45% 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 Monrovia, MD