Holtsville, NY: High Radon Risk — 53/100 (2026)
1 ZIP code · 2 water systems · Updated 2026-06-03
Holtsville's water safety record falls below average in NY — compliance violations span multiple service areas, and several systems have recorded exceedances that trigger federal notification requirements under the Safe Drinking Water Act.
How Holtsville Compares
Data: EPA SDWIS Last verified: 2026-06-03
Holtsville Water: The Quick Version
- Homes built before 1986: 62% — older plumbing may contain lead solder.
- Estimated remediation: $3,000 per household.
- CDC health risk index: 11.13.
Water Systems Serving Holtsville
At present, 2 utilities serve the bulk of Holtsville, NY's residential water connections out of 2 systems active in the area, spread across independent providers with separate infrastructure and compliance obligations.
Overview
We track water quality and home safety data for 1 ZIP code in Holtsville, New York (population ~13,194), covering 2 community water systems serving approximately 1,100,075 people region-wide.
No EPA violations recorded across any ZIP codes in Holtsville — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Holtsville: 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
Holtsville water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Holtsville
- 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 |
|---|---|---|---|
| 11742 | D | SUFFOLK COUNTY WATER AUTHORITY | 1,100,000 |
All ZIP Codes in Holtsville
- 11742 [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 Holtsville
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 Holtsville's Housing Stock?
With 62% 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
Heavily weighted toward older construction, Holtsville's housing stock carries a median build year of 1971. That profile puts a majority of homes in the era when lead-soldered copper plumbing was standard practice.
Over half of homes in Holtsville 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.
Holtsville: Remediation Cost in Perspective
What does remediation cost in financial context for Holtsville homeowners? Proportionally very little — the equity share here is low, and addressing documented issues is a manageable planning question rather than a material financial burden.
Remediation costs in Holtsville are relatively low compared to home values. The $2,000–$4,100 estimated range is a small fraction of median property value. Home values are 31% above the New York average.
Protecting Children from Lead in Holtsville
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.
When older housing represents 62% of the local inventory or aggregate readings approach the federal action level, an in-home check becomes the standard way to translate citywide averages into the specific reality of an individual Holtsville address.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Climate-Related Water Risk for Holtsville
Within the NFIP's national dataset, Holtsville falls in moderate-exposure territory — 8 documented incidents spanning multiple decades, with 100% of local ZIP codes sitting inside FEMA flood boundaries. That combination warrants inclusion in any thorough local water quality review.
Holtsville has a moderate flood history with 8 FEMA claims averaging $8,734 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>$3,000</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 Holtsville
- 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 62% 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 Holtsville, NY