Water Quality in New Hampshire
710 water systems • 168 cities • EPA SDWIS Data
710
Water Systems
6,968
Total Violations
1,699
Health-Based Violations
920,024
Population Served
Overview
New Hampshire has 710 active community water systems serving 920,024 people. These systems have accumulated 6,968 EPA Safe Drinking Water Act violations on record, of which 1,699 are health-based violations (meaning a contaminant exceeded safe levels).
Common contaminants found in violations: Chlorine Dioxide, Disinfection Byproducts, E. coli, Barium, Fecal Coliform, TTHM, Total Haloacetic Acids (HAA5), Lead, Asbestos, HAA5.
Cities with Most Violations in New Hampshire
| # | City | Violations | Health-Based | Water Systems | Population |
|---|---|---|---|---|---|
| 1 | Moultonborough | 268 | 52 | 26 | 6,089 |
| 2 | Gilford | 227 | 30 | 22 | 3,801 |
| 3 | Bedford | 205 | 12 | 17 | 1,309 |
| 4 | Lunenburg | 195 | 4 | 3 | 247 |
| 5 | Glen | 157 | 114 | 12 | 2,217 |
| 6 | Nashua | 143 | 44 | 70 | 130,094 |
| 7 | Londonderry | 143 | 6 | 2 | 116 |
| 8 | Exeter | 140 | 62 | 19 | 15,462 |
| 9 | Concord | 137 | 45 | 14 | 47,171 |
| 10 | Merrimack | 137 | 3 | 4 | 25,697 |
Largest Cities in New Hampshire
| # | City | Population | Violations | Water Systems |
|---|---|---|---|---|
| 1 | Nashua | 130,094 | 143 | 70 |
| 2 | Manchester | 125,976 | 112 | 18 |
| 3 | Concord | 47,171 | 137 | 14 |
| 4 | Portsmouth | 44,419 | 68 | 10 |
| 5 | Monroe | 36,428 | 52 | 8 |
| 6 | Keene | 30,434 | 19 | 3 |
| 7 | Dover | 29,346 | 17 | 4 |
| 8 | Merrimack | 25,697 | 137 | 4 |
| 9 | Rochester | 25,510 | 22 | 6 |
| 10 | Salem | 21,300 | 36 | 5 |
All Cities in New Hampshire
| City | Population | Violations | Health Violations | Contaminants |
|---|---|---|---|---|
| Nashua | 130,094 | 143 | 44 | Barium, Chlorine Dioxide, Copper +3 more |
| Manchester | 125,976 | 112 | 17 | Barium, Chlorine Dioxide, Disinfection Byproducts +1 more |
| Concord | 47,171 | 137 | 45 | Chlorine Dioxide, Disinfection Byproducts, E. coli +3 more |
| Portsmouth | 44,419 | 68 | 17 | Chlorine Dioxide, Disinfection Byproducts, E. coli +1 more |
| Monroe | 36,428 | 52 | 18 | Barium, Chlorine Dioxide, Disinfection Byproducts +1 more |
| Keene | 30,434 | 19 | 5 | Disinfection Byproducts, Fecal Coliform |
| Dover | 29,346 | 17 | 1 | Disinfection Byproducts |
| Merrimack | 25,697 | 137 | 3 | Barium, Chlorine Dioxide |
| Rochester | 25,510 | 22 | 5 | Disinfection Byproducts, TTHM, Total Haloacetic Acids (HAA5) |
| Salem | 21,300 | 36 | 4 | Disinfection Byproducts |
| Lakeport | 21,000 | 0 | 0 | |
| Derry | 18,748 | 106 | 44 | Barium, Chlorine Dioxide, Disinfection Byproducts +3 more |
| Hudson | 16,758 | 2 | 0 | |
| Durham | 16,455 | 36 | 18 | Barium |
| Exeter | 15,462 | 140 | 62 | Barium, Chlorine Dioxide, Disinfection Byproducts +3 more |
| Seabrook | 14,074 | 23 | 0 | |
| Somersworth | 12,060 | 7 | 1 | Chlorine Dioxide |
| Lebanon | 11,022 | 34 | 9 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Atkinson | 10,815 | 128 | 42 | Barium, Chlorine Dioxide, Disinfection Byproducts +3 more |
| Milford | 9,644 | 19 | 1 | Chlorine Dioxide |
| Berlin | 9,575 | 1 | 0 | |
| Claremont | 9,000 | 3 | 2 | E. coli |
| Hanover | 8,500 | 0 | 0 | |
| Hooksett | 7,720 | 9 | 4 | Barium |
| Plymouth | 7,439 | 25 | 3 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Franklin | 7,350 | 5 | 0 | |
| Littleton | 6,563 | 3 | 1 | E. coli |
| North Conway | 6,518 | 112 | 2 | Disinfection Byproducts, E. coli |
| Wolfeboro | 6,497 | 50 | 8 | Barium, Disinfection Byproducts |
| Moultonborough | 6,089 | 268 | 52 | Barium, Chlorine Dioxide, Disinfection Byproducts +3 more |
| Pembroke | 5,235 | 6 | 0 | |
| Newmarket | 5,055 | 1 | 0 | |
| Newport | 5,000 | 0 | 0 | |
| Meredith | 4,516 | 48 | 14 | Contaminant 2920, Disinfection Byproducts, E. coli |
| Peterborough | 4,500 | 55 | 0 | |
| Goffstown | 4,443 | 34 | 11 | Chlorine Dioxide, Disinfection Byproducts, Total Haloacetic Acids (HAA5) |
| Intervale | 4,437 | 42 | 27 | Chlorine Dioxide, Disinfection Byproducts, HAA5 +1 more |
| Rye | 4,300 | 2 | 2 | E. coli |
| Jaffrey | 4,200 | 6 | 0 | |
| Gilford | 3,801 | 227 | 30 | Barium, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Raymond | 3,692 | 34 | 11 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Conway | 3,595 | 98 | 50 | Disinfection Byproducts, E. coli, Haloacetic Acids +1 more |
| Bristol | 3,575 | 0 | 0 | |
| Grantham | 3,400 | 8 | 0 | |
| Hinsdale | 3,400 | 101 | 0 | |
| Lincoln | 3,300 | 17 | 12 | TTHM, Total Haloacetic Acids (HAA5) |
| Farmington | 3,250 | 5 | 0 | |
| Waterville Valley | 3,150 | 8 | 0 | |
| Henniker | 3,149 | 16 | 4 | Disinfection Byproducts, Lead |
| North Woodstock | 2,950 | 3 | 0 | |
| Winchester | 2,940 | 4 | 0 | |
| Woodsville | 2,862 | 7 | 2 | Disinfection Byproducts |
| Campton | 2,854 | 104 | 14 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Charlestown | 2,850 | 18 | 0 | |
| New London | 2,750 | 3 | 0 | |
| Northumberland | 2,715 | 8 | 0 | |
| Gorham | 2,685 | 2 | 0 | |
| Tilton | 2,670 | 50 | 0 | |
| Epping | 2,488 | 49 | 29 | Barium, Chlorine Dioxide, E. coli |
| Lancaster | 2,450 | 3 | 3 | Total Haloacetic Acids (HAA5) |
| Alton | 2,263 | 36 | 13 | Barium, Chlorine Dioxide, Disinfection Byproducts +1 more |
| Sunapee | 2,236 | 23 | 14 | Chlorine Dioxide, HAA5, Haloacetic Acids +1 more |
| Glen | 2,217 | 157 | 114 | Asbestos, Chlorine Dioxide, Disinfection Byproducts +4 more |
| Hillsborough | 2,000 | 2 | 0 | |
| Enfield | 1,844 | 46 | 8 | Chlorine Dioxide, Disinfection Byproducts, E. coli +2 more |
| Ashland | 1,815 | 6 | 0 | |
| Epsom | 1,810 | 59 | 32 | Barium, Chlorine Dioxide, E. coli |
| Wilton | 1,790 | 0 | 0 | |
| Bethlehem | 1,750 | 48 | 45 | TTHM, Total Haloacetic Acids (HAA5) |
| Antrim | 1,695 | 4 | 0 | |
| Rollinsford | 1,688 | 6 | 4 | Barium, Disinfection Byproducts, PFOS |
| Whitefield | 1,640 | 10 | 3 | E. coli |
| Belmont | 1,582 | 67 | 3 | Chlorine Dioxide, Disinfection Byproducts |
| Greenville | 1,572 | 17 | 0 | |
| Sanbornville | 1,425 | 25 | 1 | Disinfection Byproducts |
| N Swanzey | 1,400 | 2 | 0 | |
| Brentwood | 1,387 | 2 | 0 | |
| Center Ossipee | 1,380 | 63 | 1 | Chlorine Dioxide |
| Bedford | 1,309 | 205 | 12 | Barium, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Colebrook | 1,300 | 27 | 3 | Barium, Disinfection Byproducts |
| Hillsboro | 1,300 | 22 | 6 | Barium, Chlorine Dioxide |
| Meriden | 1,297 | 11 | 0 | |
| Walpole | 1,287 | 13 | 3 | Chlorine Dioxide, Disinfection Byproducts |
| Madison | 1,200 | 17 | 10 | Haloacetic Acids |
| Troy | 1,200 | 2 | 1 | Disinfection Byproducts |
| Northwood | 1,174 | 43 | 8 | Barium, E. coli, Endrin |
| Franconia | 1,010 | 30 | 4 | Disinfection Byproducts |
| Lisbon | 1,010 | 4 | 0 | |
| Canaan | 984 | 56 | 4 | Disinfection Byproducts, TTHM |
| Jackson | 885 | 15 | 10 | Total Haloacetic Acids (HAA5) |
| Warner | 878 | 18 | 2 | Barium, Disinfection Byproducts |
| Twin Mountain | 875 | 0 | 0 | |
| Barrington | 863 | 49 | 4 | Disinfection Byproducts |
| Bartlett | 854 | 95 | 61 | Asbestos, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Marlborough | 850 | 1 | 0 | |
| Freedom | 845 | 61 | 15 | Chlorine Dioxide, Disinfection Byproducts, E. coli +2 more |
| Loudon | 808 | 57 | 28 | Barium, Chlorine Dioxide, Disinfection Byproducts |
| Allenstown | 800 | 6 | 0 | |
| Haverhill | 790 | 17 | 2 | Total Organic Carbon |
| Stratham | 788 | 119 | 59 | Barium, Chlorine Dioxide, Copper +2 more |
| North Haverhill | 777 | 19 | 2 | Disinfection Byproducts |
| Bellows Falls | 750 | 46 | 0 | |
| Windham | 725 | 79 | 30 | Chlorine Dioxide, Disinfection Byproducts, E. coli +2 more |
| Andover | 722 | 82 | 55 | Chlorine Dioxide, E. coli, Fecal Coliform +3 more |
| Hampton | 685 | 37 | 8 | Barium, Chlorine Dioxide, Disinfection Byproducts +2 more |
| Swanzey | 666 | 14 | 2 | E. coli |
| Windsor | 658 | 40 | 9 | Disinfection Byproducts, E. coli |
| Ossipee | 634 | 39 | 3 | Total Organic Carbon |
| Unity | 625 | 12 | 0 | |
| East Hampstead | 590 | 59 | 23 | Barium, Chlorine Dioxide, Disinfection Byproducts +1 more |
| Newfields | 550 | 4 | 1 | Disinfection Byproducts |
| Hancock | 450 | 5 | 0 | |
| Contoocook | 440 | 22 | 7 | E. coli, Haloacetic Acids |
| Weare | 431 | 65 | 25 | Barium, Chlorine Dioxide, Disinfection Byproducts +1 more |
| West Swanzey | 430 | 46 | 3 | Disinfection Byproducts |
| West Stewartstown | 428 | 1 | 0 | |
| Lochmere | 405 | 1 | 0 | |
| Laconia | 391 | 72 | 3 | Disinfection Byproducts, E. coli |
| San Francisco | 388 | 59 | 0 | |
| Hales Location | 385 | 3 | 3 | E. coli |
| Pelham | 357 | 24 | 18 | HAA5, Haloacetic Acids |
| Plaistow | 349 | 16 | 7 | Barium, Chlorine Dioxide, E. coli |
| Greenfield | 300 | 20 | 9 | Chlorine Dioxide, Disinfection Byproducts, TTHM +1 more |
| Stratford | 300 | 7 | 0 | |
| Deering | 290 | 11 | 0 | |
| Danville | 266 | 22 | 5 | E. coli |
| Glencliff | 260 | 73 | 14 | Chlorine Dioxide, E. coli |
| Amesbury | 251 | 25 | 7 | Chlorine Dioxide, Copper, E. coli |
| Boston | 250 | 1 | 0 | |
| Rindge | 250 | 11 | 0 | |
| Pawtucket | 250 | 5 | 2 | E. coli |
| Lunenburg | 247 | 195 | 4 | Chlorine Dioxide, Disinfection Byproducts |
| Tamworth | 247 | 39 | 6 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Center Conway | 246 | 4 | 0 | |
| Bow | 243 | 32 | 12 | Barium, Chlorine Dioxide |
| Warren | 242 | 24 | 1 | Disinfection Byproducts |
| Pittsburg | 233 | 8 | 0 | |
| Center Harbor | 225 | 1 | 1 | Disinfection Byproducts |
| Hopkinton | 215 | 6 | 5 | Chlorine Dioxide |
| Newbury | 208 | 1 | 0 | |
| Marblehead | 200 | 1 | 0 | |
| Holderness | 193 | 15 | 6 | Chlorine Dioxide, Disinfection Byproducts |
| Fremont | 185 | 13 | 2 | Chlorine Dioxide, Disinfection Byproducts |
| Errol | 183 | 12 | 1 | Disinfection Byproducts |
| Sandown | 173 | 17 | 3 | Chlorine Dioxide, Disinfection Byproducts |
| Atkinston | 170 | 1 | 0 | |
| Webster | 165 | 24 | 3 | Chlorine Dioxide |
| Fitzwilliam | 161 | 12 | 2 | Chlorine Dioxide, Haloacetic Acids |
| Center Tuftonboro | 143 | 17 | 4 | E. coli |
| New Ipswich | 136 | 50 | 3 | Disinfection Byproducts, HAA5 |
| Sanbornton | 134 | 3 | 0 | |
| Hill | 130 | 2 | 1 | Disinfection Byproducts |
| Francestown | 130 | 3 | 0 | |
| Hebron | 128 | 3 | 1 | Disinfection Byproducts |
| Orford | 128 | 2 | 1 | Disinfection Byproducts |
| N Quincy | 125 | 6 | 1 | Disinfection Byproducts |
| Westborough | 123 | 15 | 9 | Chlorine Dioxide, E. coli, Total Organic Carbon |
| E Wakefield | 120 | 5 | 0 | |
| Arlington | 118 | 2 | 1 | Disinfection Byproducts |
| Londonderry | 116 | 143 | 6 | Barium, Chlorine Dioxide |
| Bennington | 112 | 22 | 1 | Chlorine Dioxide |
| New Durham | 111 | 41 | 7 | Chlorine Dioxide, Disinfection Byproducts, E. coli |
| Bath | 100 | 6 | 1 | Chlorine Dioxide |
| Chester | 100 | 1 | 0 | |
| Portland | 100 | 0 | 0 | |
| Hollis | 100 | 6 | 6 | Haloacetic Acids |
| Great Neck | 100 | 37 | 28 | Chlorine Dioxide, HAA5, Haloacetic Acids +1 more |
| Newton | 100 | 2 | 0 |
Data Sources
Drinking water data from the EPA Safe Drinking Water Information System (SDWIS). Only active community water systems (CWS) serving 100+ people are included.