Londonderry, NH: 2 Health Violations — 76/100 (2026)
1 ZIP code · 9 water systems · Updated 2026-06-03
EPA compliance records for Londonderry tell a largely clear story: violation rates are low, health-based exceedances are uncommon, and the city's grade puts it well above average within NH.
How Londonderry Compares
Data: EPA SDWIS Last verified: 2026-06-03
What You Should Know About Londonderry Water
- Your city's water systems recorded 5 violations in the past 5 years.
- Average lead level: 0.004 mg/L.
- Homes built before 1986: 53% — older plumbing may contain lead solder.
- Estimated remediation: $2,500 per household.
- CDC health risk index: 11.66.
Who Supplies Your Water in Londonderry
Water service in Londonderry, NH is split across 3 utilities out of 9 tracked federally, each operating its own infrastructure and compliance record.
Overview
We track water quality and home safety data for 1 ZIP code in Londonderry, New Hampshire (population ~25,930), covering 9 community water systems serving approximately 155,628 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. 2 health-based violations documented.
Home Safety Score
Average Home Safety Score for Londonderry: B (76/100)
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
Londonderry water systems draw from: Groundwater, Surface water.
Lead & Copper
- Average lead level (90th percentile): 0.0040 mg/L (EPA action level: 0.015 mg/L)
- 0 ZIP codes exceed the EPA lead action level
Radon Risk
Dominant radon zone: Zone 2 (Moderate Risk)
The EPA recommends testing homes in Zone 1 and Zone 2 areas for radon.
Top Contaminants
| Contaminant | Category | Violations | ZIPs Affected |
|---|---|---|---|
| Consumer Confidence Report Rule | Reporting | 6 | 1 |
| Gross Beta | Radionuclides | 2 | 1 |
| Contaminant 0700 | Other | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 03053 | B | 5 | 2 | Londonderry |
All ZIP Codes in Londonderry
- 03053 [B] — 5 violations ⚠
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.
Health Outcomes in Londonderry
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
Top Contaminants in Londonderry Water
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Housing & Infrastructure in Londonderry
With 53% 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
Two dates define the high-risk tiers of residential plumbing from a lead standpoint: 1970, before which lead pipes were commonly installed for service connections, and 1986, before which lead solder was standard in copper plumbing. A median build year of 1985 places Londonderry's housing distribution well within that older risk zone. The bar chart above breaks down how much of the stock falls into each era — and the pre-1986 share alone represents more than half the residential inventory, making plumbing-era risk a defining characteristic of the local water safety picture.
Over half of homes in Londonderry 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 Londonderry Homeowners
Placing remediation in the context of Londonderry's property market, the equity share is low — most homeowners here are weighing a financial commitment that fits comfortably within routine property planning, far from the threshold where remediation becomes a material equity decision rather than a standard upkeep consideration.
Remediation costs in Londonderry are relatively low compared to home values. The $1,350–$4,000 estimated range is a small fraction of median property value. Home values are 27% above the New Hampshire average.
Lead Exposure Risk for Children in Londonderry
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 53% of Londonderry 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.
Flood & Climate Risk in Londonderry
Flood history in Londonderry spans 41 NFIP claims and 100% flood zone coverage — enough to place it in moderate-exposure territory where flood events are genuinely recurring rather than statistical outliers. That distinction matters for water quality assessment because the connection between flooding and water safety is not uniform across communities. In low-exposure areas, flooding rarely generates the conditions needed to compromise treatment or distribution infrastructure. In high-exposure areas, it can do so repeatedly. Moderate-exposure communities sit in between: flood events occur with enough frequency to make periodic infrastructure stress a reasonable concern, particularly for private well owners and residents in lower-elevation FEMA-designated zones.
Londonderry has a moderate flood history with 41 FEMA claims averaging $9,944 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>$2,500</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 Londonderry, NH