Data: EPA SDWIS, NWS, State plumbing boards, Rewiring America Last verified: 2026-06-03

Statewide water monitoring for New Hampshire reveals a below-average compliance pattern — health-based violations are documented across several regions, and the aggregate grade reflects shortfalls spread across the state's utility footprint rather than concentrated in one area.

Score Distribution

How New Hampshire's 282 ZIP codes are distributed across safety grades.

Top 10 Safest ZIP Codes in New Hampshire

Highest Home Safety Scores in the state.

10 Lowest-Scoring ZIP Codes in New Hampshire

County Rankings

Water quality breakdown by county. 10 counties with data in New Hampshire.

Most Common Contaminants in New Hampshire

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Overview

We track water quality, weather alerts, plumbing regulations, and energy rebates for 282 ZIP codes across New Hampshire, covering 446 community water systems that serve approximately 811,880 people.

146 of 282 ZIP codes (52%) have recorded EPA violations. 301 health-based violations have been documented.

Plumbing Regulations

New Hampshire follows the International Plumbing Code (2018 edition).

• Plumbing code: IPC (2018)
• Homeowner DIY: Licensed plumber required
• Water heater permit: Required
• Annual backflow test: Required

Full New Hampshire regulations →

Areas with Most Violations

Areas with No Violations

Home Safety Score

Average Home Safety Score for New Hampshire: C (64/100)

Lead & Copper

• Average lead level (90th percentile): 0.0231 mg/L (EPA action level: 0.015 mg/L)
• 33 ZIP codes exceed the EPA lead action level

Radon Risk

• High risk (Zone 1): 32 ZIP codes (11%)
• Moderate risk (Zone 2): 250 ZIP codes
• Low risk (Zone 3): 0 ZIP codes

ZIP Code Reports for New Hampshire

Largest Communities

Lowest Safety Scores

Highest Safety Scores

All 282 ZIP Codes in New Hampshire

• 03601 (Acworth) [D]
• 03602 (Alstead) [B]
• 03809 (Alton) [C] — 11 violations ⚠
• 03810 (Alton Bay) [C]
• 03031 (Amherst) [C] — 1 violation
• 03216 (Andover) [D] — 15 violations ⚠
• 03440 (Antrim) [B]
• 03217 (Ashland) [B] — 1 violation
• 03441 (Ashuelot) [C]
• 03811 (Atkinson) [C] — 9 violations ⚠
• 03032 (Auburn) [B]
• 03218 (Barnstead) [B]
• 03825 (Barrington) [B] — 1 violation
• 03812 (Bartlett) [C] — 11 violations ⚠
• 03740 (Bath) [B] — 1 violation
• 03110 (Bedford) [B]
• 03220 (Belmont) [D] — 1 violation
• 03442 (Bennington) [B]
• 03570 (Berlin) [B] — 1 violation
• 03574 (Bethlehem) [D] — 4 violations ⚠
• 03304 (Bow) [B] — 10 violations ⚠
• 03221 (Bradford) [D]
• 03575 (Bretton Woods) [C]
• 03222 (Bristol) [B]
• 03033 (Brookline) [C]
• 03223 (Campton) [D] — 3 violations ⚠
• 03741 (Canaan) [D] — 14 violations ⚠
• 03034 (Candia) [B] — 2 violations
• 03224 (Canterbury) [B]
• 03225 (Center Barnstead) [C]
• 03813 (Center Conway) [D] — 1 violation
• 03226 (Center Harbor) [B]
• 03814 (Center Ossipee) [F] — 3 violations
• 03227 (Center Sandwich) [D]
• 03815 (Center Strafford) [D]
• 03816 (Center Tuftonboro) [F] — 5 violations ⚠
• 03603 (Charlestown) [C] — 1 violation
• 03036 (Chester) [B] — 1 violation
• 03443 (Chesterfield) [C]
• 03258 (Chichester) [C]
• 03817 (Chocorua) [D] — 3 violations ⚠
• 03743 (Claremont) [B] — 1 violation ⚠
• 03576 (Colebrook) [B] — 2 violations
• 03301 (Concord) [D] — 21 violations ⚠
• 03302 (Concord) [C] — 21 violations ⚠
• 03303 (Concord) [D] — 21 violations ⚠
• 03305 (Concord) [D] — 21 violations ⚠
• 03229 (Contoocook) [B] — 9 violations ⚠
• 03818 (Conway) [C] — 6 violations ⚠
• 03745 (Cornish) [C]
• 03746 (Cornish Flat) [D]
• 03230 (Danbury) [C]
• 03819 (Danville) [B] — 4 violations ⚠
• 03037 (Deerfield) [B]
• 03038 (Derry) [B] — 1 violation
• 03820 (Dover) [B] — 1 violation
• 03821 (Dover) [B] — 1 violation
• 03822 (Dover) [B] — 1 violation
• 03604 (Drewsville) [D]
• 03444 (Dublin) [C]
• 03046 (Dunbarton) [C]
• 03824 (Durham) [B] — 1 violation
• 03231 (East Andover) [D]
• 03040 (East Candia) [C]
• 03041 (East Derry) [D]
• 03826 (East Hampstead) [B] — 4 violations ⚠
• 03827 (East Kingston) [B]
• 03830 (East Wakefield) [D]
• 03832 (Eaton Center) [D]
• 03882 (Effingham) [D] — 11 violations ⚠
• 03233 (Elkins) [D]
• 03748 (Enfield) [B] — 8 violations ⚠
• 03749 (Enfield Center) [D]
• 03042 (Epping) [D] — 9 violations ⚠
• 03234 (Epsom) [C] — 5 violations ⚠
• 03579 (Errol) [B] — 1 violation
• 03750 (Etna) [D]
• 03833 (Exeter) [B] — 2 violations
• 03835 (Farmington) [B]
• 03447 (Fitzwilliam) [C]
• 03043 (Francestown) [B]
• 03580 (Franconia) [C] — 5 violations
• 03235 (Franklin) [B]
• 03836 (Freedom) [C] — 2 violations
• 03044 (Fremont) [B]
• 03751 (Georges Mills) [D]
• 03249 (Gilford) [B] — 14 violations ⚠
• 03237 (Gilmanton) [C]
• 03837 (Gilmanton Iron Works) [D]
• 03448 (Gilsum) [C]
• 03838 (Glen) [F] — 27 violations ⚠
• 03238 (Glencliff) [D] — 12 violations ⚠
• 03045 (Goffstown) [C] — 6 violations ⚠
• 03581 (Gorham) [B]
• 03752 (Goshen) [C]
• 03240 (Grafton) [D]
• 03753 (Grantham) [B] — 4 violations
• 03047 (Greenfield) [D] — 11 violations ⚠
• 03840 (Greenland) [D]
• 03048 (Greenville) [C] — 7 violations
• 03582 (Groveton) [C]
• 03754 (Guild) [D]
• 03841 (Hampstead) [B] — 1 violation
• 03842 (Hampton) [C] — 5 violations ⚠
• 03843 (Hampton) [B] — 5 violations ⚠
• 03844 (Hampton Falls) [B]
• 03449 (Hancock) [B]
• 03755 (Hanover) [B]
• 03450 (Harrisville) [D]
• 03765 (Haverhill) [B] — 4 violations
• 03241 (Hebron) [B]
• 03242 (Henniker) [D] — 1 violation ⚠
• 03243 (Hill) [B]
• 03244 (Hillsborough) [C] — 3 violations
• 03451 (Hinsdale) [B]
• 03245 (Holderness) [D] — 2 violations ⚠
• 03049 (Hollis) [B] — 2 violations ⚠
• 03106 (Hooksett) [B]
• 03051 (Hudson) [B] — 1 violation
• 03845 (Intervale) [C] — 3 violations ⚠
• 03846 (Jackson) [C] — 4 violations ⚠
• 03452 (Jaffrey) [B] — 3 violations
• 03583 (Jefferson) [D]
• 03847 (Kearsarge) [D]
• 03431 (Keene) [B] — 1 violation
• 03435 (Keene) [B] — 1 violation
• 03848 (Kingston) [C] — 2 violations ⚠
• 03246 (Laconia) [B] — 1 violation
• 03247 (Laconia) [B] — 1 violation
• 03584 (Lancaster) [B]
• 03756 (Lebanon) [B] — 2 violations ⚠
• 03766 (Lebanon) [B] — 2 violations ⚠
• 03861 (Lee) [B] — 2 violations ⚠
• 03605 (Lempster) [D]
• 03251 (Lincoln) [B] — 1 violation
• 03585 (Lisbon) [C] — 2 violations
• 03052 (Litchfield) [B]
• 03561 (Littleton) [B] — 1 violation ⚠
• 03252 (Lochmere) [B] — 1 violation
• 03053 (Londonderry) [B] — 5 violations ⚠
• 03307 (Loudon) [D] — 11 violations ⚠
• 03768 (Lyme) [C]
• 03769 (Lyme Center) [D]
• 03082 (Lyndeborough) [D]
• 03823 (Madbury) [D] — 15 violations ⚠
• 03849 (Madison) [F] — 8 violations ⚠
• 03101 (Manchester) [B] — 9 violations ⚠
• 03102 (Manchester) [B] — 9 violations ⚠
• 03103 (Manchester) [B] — 9 violations ⚠
• 03104 (Manchester) [B] — 9 violations ⚠
• 03105 (Manchester) [B] — 9 violations ⚠
• 03107 (Manchester) [B] — 9 violations ⚠
• 03108 (Manchester) [B] — 9 violations ⚠
• 03109 (Manchester) [B] — 9 violations ⚠
• 03111 (Manchester) [B] — 9 violations ⚠
• 03455 (Marlborough) [B]
• 03456 (Marlow) [C]
• 03850 (Melvin Village) [D]
• 03253 (Meredith) [B] — 6 violations ⚠
• 03770 (Meriden) [B] — 1 violation
• 03054 (Merrimack) [B] — 2 violations
• 03588 (Milan) [B] — 1 violation
• 03055 (Milford) [B] — 2 violations
• 03851 (Milton) [C] — 2 violations
• 03852 (Milton Mills) [D]
• 03853 (Mirror Lake) [D]
• 03771 (Monroe) [B] — 9 violations ⚠
• 03057 (Mont Vernon) [D]
• 03254 (Moultonborough) [D] — 12 violations ⚠
• 03589 (Mount Washington) [D]
• 03060 (Nashua) [B]
• 03061 (Nashua) [B]
• 03062 (Nashua) [B]
• 03063 (Nashua) [B]
• 03064 (Nashua) [B]
• 03457 (Nelson) [D]
• 03070 (New Boston) [C]
• 03854 (New Castle) [B] — 1 violation
• 03855 (New Durham) [B] — 21 violations ⚠
• 03256 (New Hampton) [F] — 33 violations ⚠
• 03071 (New Ipswich) [B] — 2 violations
• 03257 (New London) [B]
• 03255 (Newbury) [C] — 2 violations
• 03856 (Newfields) [B]
• 03857 (Newmarket) [B]
• 03773 (Newport) [D] — 2 violations
• 03858 (Newton) [B]
• 03859 (Newton Junction) [C]
• 03860 (North Conway) [C] — 4 violations
• 03862 (North Hampton) [D]
• 03774 (North Haverhill) [B] — 3 violations
• 03073 (North Salem) [C]
• 03259 (North Sandwich) [D]
• 03590 (North Stratford) [C]
• 03260 (North Sutton) [D]
• 03609 (North Walpole) [D]
• 03262 (North Woodstock) [B]
• 03261 (Northwood) [B] — 2 violations
• 03290 (Nottingham) [B] — 1 violation
• 03777 (Orford) [B]
• 03864 (Ossipee) [F] — 4 violations
• 03076 (Pelham) [C] — 6 violations ⚠
• 03458 (Peterborough) [C] — 2 violations
• 03779 (Piermont) [D]
• 03780 (Pike) [C]
• 03592 (Pittsburg) [B]
• 03263 (Pittsfield) [B]
• 03781 (Plainfield) [B]
• 03865 (Plaistow) [C] — 4 violations ⚠
• 03264 (Plymouth) [B] — 2 violations ⚠
• 03801 (Portsmouth) [B] — 3 violations ⚠
• 03802 (Portsmouth) [B] — 3 violations ⚠
• 03803 (Portsmouth) [B] — 3 violations ⚠
• 03804 (Portsmouth) [B] — 3 violations ⚠
• 03593 (Randolph) [D]
• 03077 (Raymond) [B] — 8 violations ⚠
• 03461 (Rindge) [C]
• 03839 (Rochester) [B] — 14 violations ⚠
• 03866 (Rochester) [B] — 14 violations ⚠
• 03867 (Rochester) [B] — 14 violations ⚠
• 03868 (Rochester) [B] — 14 violations ⚠
• 03869 (Rollinsford) [D] — 3 violations ⚠
• 03266 (Rumney) [D] — 3 violations ⚠
• 03870 (Rye) [C] — 1 violation ⚠
• 03871 (Rye Beach) [D]
• 03079 (Salem) [C] — 5 violations ⚠
• 03268 (Salisbury) [C]
• 03269 (Sanbornton) [B] — 1 violation
• 03872 (Sanbornville) [D] — 2 violations ⚠
• 03873 (Sandown) [B]
• 03874 (Seabrook) [B] — 6 violations
• 03875 (Silver Lake) [D]
• 03878 (Somersworth) [B] — 2 violations ⚠
• 03607 (South Acworth) [D]
• 03272 (South Newbury) [D]
• 03273 (South Sutton) [C]
• 03883 (South Tamworth) [D]
• 03462 (Spofford) [C]
• 03284 (Springfield) [D]
• 03464 (Stoddard) [C]
• 03884 (Strafford) [B] — 2 violations
• 03885 (Stratham) [C] — 9 violations ⚠
• 03586 (Sugar Hill) [C]
• 03445 (Sullivan) [D]
• 03782 (Sunapee) [B]
• 03275 (Suncook) [C] — 4 violations ⚠
• 03446 (Swanzey) [B]
• 03886 (Tamworth) [D] — 7 violations ⚠
• 03084 (Temple) [D]
• 03285 (Thornton) [D]
• 03276 (Tilton) [C] — 2 violations
• 03298 (Tilton) [B] — 2 violations
• 03299 (Tilton) [B] — 2 violations
• 03465 (Troy) [B]
• 03595 (Twin Mountain) [B]
• 03887 (Union) [C]
• 03608 (Walpole) [C] — 7 violations
• 03278 (Warner) [B] — 3 violations
• 03279 (Warren) [B] — 11 violations ⚠
• 03280 (Washington) [C]
• 03215 (Waterville Valley) [B] — 1 violation
• 03281 (Weare) [C] — 12 violations ⚠
• 03282 (Wentworth) [C]
• 03466 (West Chesterfield) [C]
• 03784 (West Lebanon) [C]
• 03291 (West Nottingham) [D]
• 03890 (West Ossipee) [D]
• 03468 (West Peterborough) [D]
• 03597 (West Stewartstown) [B]
• 03469 (West Swanzey) [B]
• 03467 (Westmoreland) [C] — 1 violation
• 03598 (Whitefield) [B] — 1 violation ⚠
• 03287 (Wilmot) [B]
• 03086 (Wilton) [B]
• 03470 (Winchester) [C] — 5 violations ⚠
• 03087 (Windham) [B]
• 03289 (Winnisquam) [B] — 5 violations
• 03894 (Wolfeboro) [C] — 2 violations ⚠
• 03896 (Wolfeboro Falls) [D]
• 03897 (Wonalancet) [D]
• 03293 (Woodstock) [B]
• 03785 (Woodsville) [B] — 1 violation

Data Sources

• Water quality: EPA Safe Drinking Water Information System (SDWIS)
• Regulations: State plumbing boards, ICC, IAPMO

Updated daily.

Frequently Asked Questions

Is the water safe to drink in New Hampshire?

New Hampshire has 446 community water systems serving 811,880 people across 282 ZIP codes. There are 809 recorded violations, including 301 health-based. 146 of 282 ZIP codes have at least one violation.

What plumbing code does New Hampshire follow?

New Hampshire follows the IPC plumbing code. A licensed plumber is generally required for plumbing work.

Is lead a concern in New Hampshire's drinking water?

33 ZIP codes in New Hampshire have lead levels exceeding the EPA action level of 0.015 mg/L.

What is the radon risk in New Hampshire?

11% of ZIP codes in New Hampshire fall in EPA Radon Zone 1 (highest risk).