Grand Isle, LA: High Radon Risk — 37/100 (2026)
1 ZIP code · 1 water system · Updated 2026-06-03
Water monitoring data from Grand Isle, LA tells a below-average story — health violations are present and system-level detail is worth reviewing before drawing conclusions.
How Grand Isle Compares
Data: EPA SDWIS Last verified: 2026-06-03
Grand Isle Water: The Quick Version
- Homes built before 1986: 69% — older plumbing may contain lead solder.
- Estimated remediation: $1,700 per household.
- CDC health risk index: 14.75 — above typical levels.
Water Systems Serving Grand Isle
Consolidated water delivery characterizes Grand Isle, LA: among 1 system in federal records, one utility holds the dominant service position — carrying the rate-setting authority, the infrastructure obligations, and the EPA reporting burden for most residential addresses.
Overview
We track water quality and home safety data for 1 ZIP code in Grand Isle, Louisiana (population ~644), covering 1 community water system serving approximately 334,903 people region-wide.
No EPA violations recorded across any ZIP codes in Grand Isle — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Grand Isle: F (37/100)
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
Grand Isle water systems draw from: Surface water.
Lead & Copper
- Lead data: not yet available for Grand Isle
- 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 |
|---|---|---|---|
| 70358 | F | NEW ORLEANS CARROLLTON WATER WORKS | 334,903 |
All ZIP Codes in Grand Isle
- 70358 [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.
CDC Health Data for Grand Isle
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 Grand Isle's Housing Stock?
With 69% 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, Grand Isle sits firmly in the older category. The median build year of 1976 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 Grand Isle 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.
Grand Isle: Remediation Cost in Perspective
In Grand Isle, property values comfortably outpace what documented remediation typically costs — the equity share is proportionally low.
Remediation costs in Grand Isle are relatively low compared to home values. The $1,100–$2,600 estimated range is a small fraction of median property value. Home values are 56% above the Louisiana average.
Protecting Children from Lead in Grand Isle
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 69% of Grand Isle 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 Grand Isle
Across the years captured by NFIP data, Grand Isle has logged 4293 flood insurance claims and carries 100% of its ZIP codes within FEMA-designated flood zones — a sustained record consistent with high flood exposure. The water quality implications run through several pathways: treatment systems repeatedly stressed by high-volume intake, private wells in FEMA zones facing recurring infiltration risk, and distribution infrastructure that has likely experienced multiple backflow episodes during large events.
Grand Isle has a significant flood history with 4,293 FEMA flood insurance claims on record, averaging $16,141 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>$1,700</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 Grand Isle
- 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 69% 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 Grand Isle, LA