Marlborough, NH Water Safety: 75/100 (2026)
1 ZIP code · 3 water systems · Updated 2026-06-03
Compared to statewide averages in NH, Marlborough scores well — health violations are below the norm and systems generally operate within federal standards.
How Marlborough Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Marlborough Residents
- Homes built before 1986: 71% — older plumbing may contain lead solder.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 12.22 — above typical levels.
Marlborough's Water Providers
In Marlborough, NH, residential water supply is distributed across multiple utilities rather than concentrated in one. The 3 leading providers out of 3 tracked systems each control their own infrastructure, file separate EPA compliance reports, and set independent rate schedules.
Overview
We track water quality and home safety data for 1 ZIP code in Marlborough, New Hampshire, covering 3 community water systems serving approximately 2,148 people.
No EPA violations recorded across any ZIP codes in Marlborough — an excellent indicator of water quality.
Home Safety Score
Average Home Safety Score for Marlborough: B (75/100)
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
Marlborough water systems draw from: Groundwater.
Lead & Copper
- Lead data: not yet available for Marlborough
- 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.
Areas with No Violations
| ZIP Code | Safety Score | System | Population |
|---|---|---|---|
| 03455 | B | Marlborough Water Works | 750 |
All ZIP Codes in Marlborough
- 03455 [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.
Marlborough Community Health Snapshot
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
Marlborough Infrastructure Age
With 71% 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
Marlborough's housing stock is predominantly older, with a median build year of 1976 that reflects decades of construction before federal plumbing standards were tightened. The 1986 ban on lead solder and the pre-1970 era of lead service lines are both relevant benchmarks here — a significant share of the residential inventory predates one or both of those cutoffs, creating an elevated baseline for plumbing-related lead risk that aggregate water quality data may not fully reflect at the household level.
Over half of homes in Marlborough 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.
How Remediation Costs Compare in Marlborough
Setting Marlborough remediation figures against its property market, the resulting ratio sits comfortably in the low tier — a classification that reflects the kind of household financial position where most homeowners can identify documented issues, schedule the work, and absorb the cost without it registering as a significant budget disruption.
Remediation costs in Marlborough are relatively low compared to home values. The $1,200–$3,300 estimated range is a small fraction of median property value. Home values are 31% below the New Hampshire average.
Marlborough: Lead Risk & Vulnerable Populations
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.
If 71% of the Marlborough inventory comes from before the federal ban on lead-bearing solder — and if utility samples sit at or near 0.015 mg/L — the gap between citywide averages and one specific faucet becomes a practical concern rather than a theoretical one. That is why one-home reads exist as a separate measurement. A certified filter through retailer networks addresses confirmed exposure where it appears in a household.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Marlborough: Flood History & Water Damage Risk
NFIP records stretching across multiple decades show Marlborough accumulating 3 claims and carrying 100% of its ZIP codes inside FEMA flood zones — evidence of meaningful exposure that extends beyond isolated incidents. The mechanisms linking flooding to water quality haven't changed: treatment facilities can be overwhelmed, wells can be infiltrated, and distribution systems can experience backflow. For a community at this exposure level, those mechanisms shift from hypothetical to periodically relevant.
Marlborough has a moderate flood history with 3 FEMA claims. 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>$2,200</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 Marlborough, NH