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 ranks 42nd among all U.S. states for total drinking water violations, out of 51 states tracked. The state has 6,968 EPA Safe Drinking Water Act violations on record across 710 water systems serving 168 cities. Of those, 1,699 are health-based violations, meaning a regulated contaminant was measured above the EPA-established safe level. New Hampshire's total violation count is 80% below the national average. Water systems in New Hampshire serve approximately 920,024 people. The most frequently cited contaminants in New Hampshire violations include Chlorine Dioxide, Disinfection Byproducts, E. coli, Barium, Fecal Coliform.
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 |
Water Quality in Other States
Alabama 13,972 violations Alaska 73,527 violations Arizona 60,414 violations Arkansas 17,031 violations California 39,276 violations Colorado 42,596 violations Connecticut 28,800 violations Delaware 1,242 violations District of Columbia 115 violations Florida 36,335 violations Georgia 32,159 violations Hawaii 182 violations Idaho 26,078 violations Illinois 30,544 violations Indiana 18,261 violations Iowa 9,389 violations Kansas 19,480 violations Kentucky 9,427 violations Louisiana 32,039 violations Maine 6,830 violations Maryland 5,321 violations Massachusetts 10,561 violations Michigan 15,820 violations Minnesota 3,784 violations Mississippi 25,296 violations Missouri 25,377 violations Montana 20,202 violations Nebraska 5,134 violations Nevada 8,167 violations New Jersey 19,332 violations New Mexico 37,115 violations New York 93,834 violations North Carolina 54,399 violations North Dakota 8,431 violations Ohio 61,604 violations Oklahoma 128,472 violations Oregon 0 violations Pennsylvania 199,265 violations Rhode Island 0 violations South Carolina 13,045 violations South Dakota 19,565 violations Tennessee 20,607 violations Texas 263,180 violations Utah 71,655 violations Vermont 12,362 violations Virginia 15,298 violations Washington 54,459 violations West Virginia 81,622 violations Wisconsin 18,533 violations Wyoming 13,783 violations
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.