64.3
County avg score
13
Cities ranked
38%
A or B grade
31%
D or F grade
13
Health violations
2
PFAS detected
Grade Distribution
How Merrimack cities scored
A
3
23%
Excellent
B
2
15%
Good
C
4
31%
Fair
D
2
15%
Poor
F
2
15%
Failing
Comparison
County vs New Hampshire average
▼ 0.6 pts below state average
City Map
Water quality across Merrimack
Each dot is a city, colored by grade. Click any city to view its full report.
Highlights
Top & bottom cities in Merrimack
Best cities
Worst cities
County context
64.6%
of residents on fluoridated water (CDC, 2020)
323
lbs/yr to surface water · top 10 TRI facilities
Industrial pollution
Top industrial polluters in Merrimack
Industrial polluters nearby
Facilities reporting the most surface-water releases in Merrimack, 2023.
Total reported releases to surface water: 323 lbs
| Facility | Top chemical | To surface water (lbs/yr) |
|---|---|---|
MERRIMACK STATION BOW, NH03304 | Ammonia | 254 |
WATTS REGULATOR CO DBA WEBSTER VALVE FRANKLIN, NH03235 | Copper | 66 |
ELEKTRISOLA INC. BOSCAWEN, NH03303 | Copper | 2 |
BROX INDUSTRIES INC HOOKSETT, NH03106 | — | — |
GE CO HOOKSETT, NH03106 | — | — |
+ 5 more facilities
Source: EPA Toxic Release Inventory (TRI) 2023
Full Rankings
All 13 cities in Merrimack
| # | City | Grade | Score | Score | Population | Violations | Issues |
|---|---|---|---|---|---|---|---|
| 1 | Franklin | A- | 89.8 | 7K | 75 | Health Unresolved | |
| 2 | Boscawen | A- | 88.6 | 4K | 15 | Health Unresolved | |
| 3 | Hooksett | A- | 85.2 | 8K | 78 | Health PFAS Unresolved | |
| 4 | Pembroke | B | 75.8 | 5K | 84 | Health PFAS Unresolved | |
| 5 | Henniker | B- | 73.8 | 3K | 70 | Health Lead Unresolved | |
| 6 | Pittsfield | C+ | 66.6 | 2K | 124 | Health Lead Unresolved | |
| 7 | New London | C+ | 65.7 | 3K | 110 | Health Lead Unresolved | |
| 8 | Warner | C | 64.7 | 878 | 28 | Health Lead Unresolved | |
| 9 | Allenstown | C- | 59.4 | 800 | 58 | Health Lead Unresolved | |
| 10 | Concord | D+ | 51.3 | 44K | 63 | Health Unresolved | |
| 11 | Epsom | D | 47.3 | 2K | 99 | Health Lead Unresolved | |
| 12 | Andover | F | 39.9 | 650 | 89 | Health Lead Unresolved | |
| 13 | Loudon | F | 28 | 808 | 374 | Health Lead Unresolved |