Old Greenwich, CT: High Radon Risk — 35/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Monitoring data across Old Greenwich reveals a persistent pattern of below-average compliance in CT — multiple service areas carry documented health violations, and the data has shown little overall improvement over recent EPA reporting cycles.
How Old Greenwich Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Old Greenwich Water
- Homes built before 1986: 72% — older plumbing may contain lead solder.
- Estimated remediation: $3,600 per household.
Who Supplies Your Water in Old Greenwich
Water supply in Old Greenwich, CT 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 Old Greenwich, Connecticut (population ~7,903), covering 2 community water systems serving approximately 351,989 people region-wide.
No EPA violations recorded across any ZIP codes in Old Greenwich — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Old Greenwich: F (35/100)
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
Old Greenwich water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Old Greenwich
- 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 |
|---|---|---|---|
| 06870 | F | AQUARION-EASTERN FAIRFIELD COUNTY | 351,756 |
All ZIP Codes in Old Greenwich
- 06870 [F]
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.
Housing & Infrastructure in Old Greenwich
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
The lead that enters tap water in older homes often comes not from the municipal supply but from the home's own plumbing — from solder used in copper joints before the 1986 federal ban, or from lead pipes installed before 1970. In Old Greenwich, where the median build year is 1965, these older materials are widespread. More than half the residential stock predates the 1986 solder ban, and a significant fraction predates 1970 as well. For residents in those homes, the city-wide water quality picture is a less relevant frame than the specific materials inside their own walls and under their own street.
Over half of homes in Old Greenwich 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 Old Greenwich Homeowners
In Old Greenwich, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Old Greenwich are relatively low compared to home values. The $2,400–$4,800 estimated range is a small fraction of median property value. Home values are 287% above the Connecticut average.
Lead Exposure Risk for Children in Old Greenwich
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.
Locally, 72% of Old Greenwich homes carry interior plumbing from the era when lead solder was still permitted in new builds, and citywide monitoring approaches or crosses the EPA action benchmark. Households can find a draw-test kit and certified filtration through verified retailers.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Flood & Climate Risk in Old Greenwich
Measured against the full NFIP dataset, Old Greenwich's flood record stands out: 703 claims accumulated over decades and 100% of ZIP codes inside FEMA-designated boundaries add up to a high-exposure profile where water infrastructure has faced recurrent stress.
Old Greenwich has a significant flood history with 703 FEMA flood insurance claims on record, averaging $28,844 per claim. With 100% of ZIP codes in FEMA-designated flood zones, flood risk is a major concern for homeowners and water quality.
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 Old Greenwich
- 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 72% 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 Old Greenwich, CT