EPA data as of Oct 2026 · page updated 2026-10-30
New Hampshire: drinking water & radon
New Hampshire has 682 active community water systems. Since 2016, 215 reported health-based violations; 211 had a latest lead result above 15 ppb; 15 measured PFOA or PFOS at or above 4 ppt.
Water systems682
With violations215
Radon zone 1 ZIPs30
ZIPs likely on wells149
Radon zones in New Hampshire
tap a countyZone 1 · highestZone 2 · moderateZone 3 · low
Most health-based violations
| New Hampton Village PCT 600 people | 50 |
| Contoocook Village PCT 1,600 people | 26 |
| Bethlehem Village Dist 1,750 people | 26 |
| Rolling Ridge 58 people | 16 |
| Exeter Water Dept 12,236 people | 16 |
| Muirfield Cluster 69 people | 12 |
| New Castle Water Works 910 people | 11 |
| Profile Apartments 90 people | 11 |
| Rockhouse Mountain 480 people | 10 |
| Northpointe Water 48 people | 9 |
Highest latest lead (90th percentile)
| Alton Water Works 1,800 people | 210 ppb |
| Lands END 50 people | 199 ppb |
| Greenville Water Dept 1,100 people | 110 ppb |
| Mountain View APTS 100 people | 72 ppb |
| Deer Cove Water 135 people | 47 ppb |
| Wediko School 280 people | 46 ppb |
| Waterville Estate VLG Dist/W 1,250 people | 37 ppb |
| Black Mountain Meadow Condos 43 people | 31 ppb |
| Meeting House Water 35 people | 28 ppb |
| 20 Jaffrey Rd 32 people | 25 ppb |
Highest PFOA / PFOS
| Hudson Water Dept 16,700 people | 9 ppt |
| Salem Water Dept 21,080 people | 8.5 ppt |
| Rye Water Dist 4,300 people | 8.3 ppt |
| Litchfield 6,920 people | 8.1 ppt |
| Seabrook Water Dept 14,000 people | 8 ppt |
| Hampstead Area Water 7,153 people | 7.5 ppt |
| Portsmouth Water Works 33,000 people | 7 ppt |
| Jaffrey Water Works 3,800 people | 6.6 ppt |
| Pembroke Water Works 5,200 people | 6.5 ppt |
| Londonderry 6,255 people | 6.4 ppt |
Largest systems
| Manchester Water Works 123,500 people | 123,500 |
| Pennichuck Water Works 88,853 people | 88,853 |
| Concord Water Dept 44,215 people | 44,215 |
| Portsmouth Water Works 33,000 people | 33,000 |
| Keene Water Dept 30,000 people | 30,000 |
| Dover Water Dept 29,000 people | 29,000 |
| Merrimack Village Dist 25,500 people | 25,500 |
| Rochester Water Dept 25,000 people | 25,000 |
| Salem Water Dept 21,080 people | 21,080 |
| Derry Water Dept 17,528 people | 17,528 |
All ZIP codes in New Hampshire
280 ZIP codes.
03031Amherst03032Auburn03033Brookline03034Candia03036Chester03037Deerfield03038Derry03040East Candia03041East Derry03042Epping03043Francestown03044Fremont03045Goffstown03046Dunbarton03047Greenfield03048Greenville03049Hollis03051Hudson03052Litchfield03053Londonderry03054Merrimack03055Milford03057Mont Vernon03060Nashua03061Nashua03062Nashua03063Nashua03064Nashua03070New Boston03071New Ipswich03073North Salem03076Pelham03077Raymond03079Salem03082Lyndeborough03084Temple03086Wilton03087Windham03101Manchester03102Manchester03103Manchester03104Manchester03105Manchester03106Hooksett03108Manchester03109Manchester03110Bedford03111Manchester03215Waterville Valley03216Andover03217Ashland03218Barnstead03220Belmont03221Bradford03222Bristol03223Campton03224Canterbury03225Center Barnstead03226Center Harbor03227Center Sandwich03229Contoocook03230Danbury03231East Andover03233Elkins03234Epsom03235Franklin03237Gilmanton03238Glencliff03240Grafton03241Hebron03242Henniker03243Hill03244Hillsborough03245Holderness03246Laconia03247Laconia03249Gilford03251Lincoln03252Lochmere03253Meredith03254Moultonborough03255Newbury03256New Hampton03257New London03258Chichester03259North Sandwich03260North Sutton03261Northwood03262North Woodstock03263Pittsfield03264Plymouth03266Rumney03268Salisbury03269Sanbornton03272South Newbury03273South Sutton03275Suncook03276Tilton03278Warner03279Warren03280Washington03281Weare03282Wentworth03284Springfield03285Thornton03287Wilmot03289Winnisquam03290Nottingham03291West Nottingham03293Woodstock03298Tilton03299Tilton03301Concord03302Concord03303Concord03304Bow03305Concord03307Loudon03431Keene03435Keene03440Antrim03441Ashuelot03442Bennington03443Chesterfield03444Dublin03445Sullivan03446Swanzey03447Fitzwilliam03448Gilsum03449Hancock03450Harrisville03451Hinsdale03452Jaffrey03455Marlborough03456Marlow03457Nelson03458Peterborough03461Rindge03462Spofford03464Stoddard03465Troy03466West Chesterfield03467Westmoreland03468West Peterborough03469West Swanzey03470Winchester03561Littleton03570Berlin03574Bethlehem03575Bretton Woods03576Colebrook03579Errol03580Franconia03581Gorham03582Groveton03583Jefferson03584Lancaster03585Lisbon03586Sugar Hill03588Milan03589Mount Washington03590North Stratford03592Pittsburg03593Randolph03595Twin Mountain03597West Stewartstown03598Whitefield03601Acworth03602Alstead03603Charlestown03604Drewsville03605Lempster03607South Acworth03608Walpole03609North Walpole03740Bath03741Canaan03743Claremont03745Cornish03746Cornish Flat03748Enfield03749Enfield Center03750Etna03751Georges Mills03752Goshen03753Grantham03754Guild03755Hanover03765Haverhill03766Lebanon03768Lyme03769Lyme Center03770Meriden03771Monroe03773Newport03774North Haverhill03777Orford03779Piermont03780Pike03781Plainfield03782Sunapee03784West Lebanon03785Woodsville03801Portsmouth03802Portsmouth03803Portsmouth03804Portsmouth03809Alton03810Alton Bay03811Atkinson03812Bartlett03813Center Conway03814Center Ossipee03815Center Strafford03816Center Tuftonboro03817Chocorua03818Conway03819Danville03820Dover03821Dover03822Dover03823Madbury03824Durham03825Barrington03826East Hampstead03827East Kingston03830East Wakefield03832Eaton Center03833Exeter03835Farmington03836Freedom03837Gilmanton Iron Works03838Glen03839Rochester03840Greenland03841Hampstead03842Hampton03843Hampton03844Hampton Falls03845Intervale03846Jackson03847Kearsarge03848Kingston03849Madison03850Melvin Village03851Milton03852Milton Mills03853Mirror Lake03854New Castle03855New Durham03856Newfields03857Newmarket03858Newton03859Newton Junction03860North Conway03861Lee03862North Hampton03864Ossipee03865Plaistow03866Rochester03867Rochester03868Rochester03869Rollinsford03870Rye03871Rye Beach03872Sanbornville03873Sandown03874Seabrook03875Silver Lake03878Somersworth03882Effingham03883South Tamworth03884Strafford03885Stratham03886Tamworth03887Union03890West Ossipee03894Wolfeboro03896Wolfeboro Falls03897Wonalancet
What this is — and isn’t. These are records your water utility and state reported to the EPA, and the EPA’s radon map for your county. They describe the system and the area, not the water from your own tap or the air in your home. For that, read your utility’s annual Consumer Confidence Report and test: lead and radon tests are inexpensive.
Questions
How many water systems in New Hampshire have violations?
215 of 682 active community water systems in New Hampshire reported at least one health-based violation since 2016 (EPA SDWIS).
What is the radon risk in New Hampshire?
30 ZIP codes are in EPA radon zone 1 (highest potential), 250 in zone 2 and 0 in zone 3. EPA recommends testing every home.