Mainland, PA: High Radon Risk — 53/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Mainland ranks below average for tap water safety in PA — health-based violations are documented across multiple service areas in recent EPA monitoring data.
How Mainland Compares
Data: EPA SDWIS Last verified: 2026-06-03
Water Systems Serving Mainland
Federal drinking water records identify 1 system operating in Mainland, PA. One of those systems serves the overwhelming majority of residential addresses, concentrating infrastructure management, rate authority, and EPA compliance reporting within a single organization.
Overview
We track water quality and home safety data for 1 ZIP code in Mainland, Pennsylvania, covering 1 community water system serving approximately 88,885 people.
No EPA violations recorded across any ZIP codes in Mainland — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Mainland: D (53/100)
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
Mainland water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Mainland
- 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 |
|---|---|---|---|
| 19451 | D | PA AMERICAN NORRISTOWN | 88,885 |
All ZIP Codes in Mainland
- 19451 [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.
Climate-Related Water Risk for Mainland
The National Flood Insurance Program captures decades of claims at the local level, building a record of cumulative community flood exposure. For Mainland, that record documents 2 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.
Mainland has a moderate flood history with 2 FEMA claims averaging $20,250 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>$3,600</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 Mainland
- 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. Homes built before 1986 may have lead solder in pipes. A licensed plumber can assess your risk.
- 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 Mainland, PA