Mendon, IL: High Radon Risk — 70/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
The water systems supplying Mendon show a track record of above-average compliance with federal standards — consistently among the better performers in IL.
How Mendon Compares
Data: EPA SDWIS Last verified: 2026-06-03
Mendon Water: The Quick Version
- Average lead level: 0.0015 mg/L.
- Homes built before 1986: 72% — older plumbing may contain lead solder.
- Estimated remediation: $2,400 per household.
- CDC health risk index: 13.78 — above typical levels.
Water Systems Serving Mendon
A single utility carries the primary residential water load in Mendon, IL — the dominant provider across 1 federally tracked system.
Overview
We track water quality and home safety data for 1 ZIP code in Mendon, Illinois, covering 1 community water system serving approximately 2,026 people.
No EPA violations recorded across any ZIP codes in Mendon — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Mendon: B (70/100)
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
Mendon water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0015 mg/L (EPA action level: 0.015 mg/L)
- 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 |
|---|---|---|---|
| 62351 | B | Mendon | 953 |
All ZIP Codes in Mendon
- 62351 [B]
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 Mendon
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 Mendon's Housing Stock?
With 72% 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, Mendon sits firmly in the older category. The median build year of 1977 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 Mendon 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.
Mendon: Remediation Cost in Perspective
Across the Mendon housing market, the estimated remediation share lands in a middle tier — not a minor footnote, but not a prohibitive burden either; the cost-to-value ratio reflects a moderate equity commitment, one that sits above routine maintenance territory and warrants a dedicated line in the household budget.
Remediation costs are moderate relative to home values in Mendon. The estimated $1,600–$3,300 range is manageable for most homeowners but still worth budgeting for. Home values are 18% below the Illinois average.
Protecting Children from Lead in Mendon
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.
Although utility-side compliance with federal Lead and Copper requirements remains the system reference, that compliance does not extend down into interior plumbing. With 72% of Mendon stock built before the solder ban and aggregate readings at or beyond the action mark, a household-level sample becomes the practical way to close that information gap.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Mendon
Mendon's flood exposure sits in the moderate range: 2 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.
Mendon has a moderate flood history with 2 FEMA claims averaging $9,636 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.
Deep Dive Reports
Detailed analysis for Mendon, IL