Merrimack, NH: 2 Violations — 72/100 (2026)
1 ZIP code · 5 water systems · Updated 2026-06-03
Looking at federal monitoring data for Merrimack, NH: the city clears benchmarks set under the Safe Drinking Water Act with room to spare — recorded exceedances are rare, and the systems serving local households have not triggered any pattern of repeat deficiencies in recent cycles.
How Merrimack Compares
Data: EPA SDWIS Last verified: 2026-06-03
Key Facts for Merrimack Residents
- Your city's water systems recorded 2 violations in the past 5 years.
- Average lead level: 0.001 mg/L.
- Homes built before 1986: 56% — older plumbing may contain lead solder.
- Estimated remediation: $2,200 per household.
- CDC health risk index: 11.54.
Merrimack's Water Providers
At present, 3 utilities serve the bulk of Merrimack, NH's residential water connections out of 5 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 Merrimack, New Hampshire (population ~27,604), covering 5 community water systems serving approximately 114,770 people region-wide.
1 of 1 ZIP code (100%) have recorded EPA violations. All violations are monitoring/reporting type.
Home Safety Score
Average Home Safety Score for Merrimack: B (72/100)
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
Merrimack water systems draw from: Groundwater.
Lead & Copper
- Average lead level (90th percentile): 0.0010 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 |
|---|---|---|---|
| Total Organic Carbon | Disinfection Byproducts | 2 | 1 |
| Revised Total Coliform Rule | Microbiological | 2 | 1 |
Areas with Most Violations
| ZIP Code | Safety Score | Violations | Health-Based | System |
|---|---|---|---|---|
| 03054 | B | 2 | 0 | Merrimack Village District |
All ZIP Codes in Merrimack
- 03054 [B] — 2 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.
Merrimack 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
What's in Merrimack's Water?
Based on EPA violation records. Check your ZIP code report for system-specific contaminant data.
Merrimack Infrastructure Age
With 56% 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
Lead solder was standard in copper plumbing until federally banned in 1986; lead pipes were common in service lines pre-1970. Merrimack's median build year of 1985 reflects a housing stock where these older materials are a pervasive feature — not a rare legacy — of the residential plumbing landscape.
Over half of homes in Merrimack 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 Merrimack
At current valuations, Merrimack sits in the low remediation-share tier — the equity impact of fixing documented issues is proportionally minor.
Remediation costs in Merrimack 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 12% above the New Hampshire average.
Merrimack: 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.
Older stock in Merrimack represents 56% of the inventory, and citywide monitoring runs at or above the federal action level — making an in-home read a standard household-level step.
Sources: EPA Lead and Copper Rule, U.S. Census Bureau ACS, CDC childhood lead poisoning prevention guidelines.
Merrimack: Flood History & Water Damage Risk
The National Flood Insurance Program captures decades of claims at the local level, building a record of cumulative community flood exposure. For Merrimack, that record documents 61 claims and 100% of ZIP codes inside FEMA-designated flood zones. What makes those numbers relevant to water quality is the set of mechanisms flooding activates: heavy precipitation that floods treatment intake zones can introduce contaminants upstream of normal filtration; well casings in low-lying areas can be infiltrated by floodwaters carrying bacteria, sediment, and chemical residue; and distribution system pressure changes during flooding can create backflow conditions. These effects become more probable as flood frequency and magnitude increase — and the NFIP record indicates both are meaningful factors locally.
Merrimack has a moderate flood history with 61 FEMA claims averaging $20,975 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>$2,200</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 Merrimack, NH