New Hampshire Water Quality — 119 Cities Tested

Analysis

New Hampshire water quality overview

New Hampshire's drinking water quality is fair overall, with an average score of 62.3 out of 100 across 119 cities tested. The median score is 66, serving a total population of 870,435 residents. 37% of cities scored a D or F, pointing to significant water quality challenges in parts of the state. PFAS "forever chemicals" were detected in 21 of 119 cities tested (18%). 15 cities exceed the 2024 EPA maximum contaminant levels. 58 cities have lead levels exceeding the EPA action level of 15 ppb, often indicating aging infrastructure with lead service lines or lead solder. The state relies on a mix of water sources: 74 cities use groundwater while 45 draw from surface water such as rivers, lakes, and reservoirs.

Key Concerns

Issues to watch in New Hampshire

21 cities

PFAS Detected

18% of tested cities have PFAS in their water supply.

58 cities

Lead Exceedances

Lead levels above the EPA action level of 15 ppb (90th percentile).

118 cities

Health Violations

19,091 total violations recorded, 116 with unresolved issues.

28 cities

Failing Systems

Received a grade of F, indicating serious water quality issues.

Contaminant Data

Explore contaminants in New Hampshire

Lead in New Hampshire → Ranked by 90th percentile level (ppb) PFAS in New Hampshire → Ranked by compounds detected Copper in New Hampshire → Ranked by 90th percentile level (mg/L)

More contaminants tested in New Hampshire

HAA5 → Chromium-6 → Arsenic → Nitrate → Strontium → 1,4-Dioxane → Manganese → Vanadium → Chlorate → Molybdenum → Cobalt → Lithium → NDMA →

State context

21

Superfund sites in New Hampshire

EPA National Priorities List

46.2%

of New Hampshire residents on fluoridated water

CDC, 2020

346

lbs released to surface water

Top 10 TRI facilities, 2023

19.5%

of New Hampshire domestic wells exceed EPA arsenic limit

USGS, 846 samples · 10 µg/L MCL

Domestic well chemistry

Private-well water in New Hampshire

Based on USGS Powell Domestic-Well Database — 629 private wells sampled across New Hampshire. These wells are not regulated by the EPA; if you draw your tap from a private well, the public-system grade above does not apply to you.

6.0 µg/L

Median arsenic in domestic wells

P90 20.0 µg/L · max 146.0 µg/L

78 µg/L

Median manganese in domestic wells

14.1% exceed 300 µg/L aesthetic limit

Industrial pollution

Top industrial water polluters in New Hampshire

Industrial polluters nearby

The 10 facilities reporting the most pounds released to surface water in New Hampshire, 2023.

Total reported releases to surface water: 346 lbs

Facility	Top chemical	To surface water (lbs/yr)
MERRIMACK STATION Electric Utilities · GRANITE SHORE POWER LLC BOW, NH03304	Ammonia	254
WATTS REGULATOR CO DBA WEBSTER VALVE Fabricated Metals · WATTS WATER TECHNOLOGIES FRANKLIN, NH03235	Copper	66
SPRAGUE RIVER ROAD TERMINAL Petroleum Bulk Terminals · HARTREE PARTNERS LP NEWINGTON, NH03801	1,2,4-Trimethylbenzene	11
MARMON UTILITY LLC Electrical Equipment · BERKSHIRE HATHAWAY INC MILFORD, NH03055	Copper	5
FREUDENBERG-NOK SEALING TECHNOLOGIES Miscellaneous Manufacturing · FREUDENBERG-NOK GENERAL PTNR BRISTOL, NH03222	Zinc compounds	4

+ 3 more facilities

Source: EPA Toxic Release Inventory (TRI) 2023

Test your own tap

Get your New Hampshire water tested

City-level data shows the source and infrastructure picture — but lead and other home-plumbing issues only show up at your tap. Find a state-certified lab, see what to test for, and what it costs.

Grade Distribution

How New Hampshire cities scored

A: 21 B: 28 C: 26 D: 16 F: 28

Best Cities

Worst Cities

City Map

Water quality across New Hampshire

Each dot is a city, colored by its water quality grade. Size reflects population served. Click any city to view its full water report.

All Cities

119 cities in New Hampshire

Full rankings →

#	City	Grade	Score	Population	Violations
1	Litchfield	A	93.5	7K	1
2	Claremont	A	90.3	9K	44
3	Antrim	A-	89.9	920	12
4	Franklin	A-	89.8	7K	75
5	Somersworth	A-	89.7	12K	38
6	Bristol	A-	89.7	4K	5
7	Keene	A-	89.2	30K	22
8	Hanover	A-	89.2	9K	50
9	Lancaster	A-	89	2K	44
10	Bedford	A-	88.8	5K	9
11	Nashua	A-	88.7	89K	4
12	Boscawen	A-	88.6	4K	15
13	Barnstead	A-	87.5	2K	74
14	Chester	A-	87.3	578	60
15	Rye	A-	86.7	4K	6
16	Marlborough	A-	86.7	850	75
17	Unity	A-	86.4	625	89
18	Littleton	A-	85.8	7K	77
19	Peterborough	A-	85.3	5K	46
20	Hooksett	A-	85.2	8K	78
21	Amherst	A-	85.1	512	114
22	Merrimack	B+	84.2	26K	42
23	Dover	B+	84	29K	58
24	Berlin	B+	83.3	10K	3
25	Whitefield	B+	81.9	2K	16
26	Grantham	B+	81	3K	50
27	Lincoln	B+	81	3K	17
28	Jaffrey	B+	80.9	4K	45
29	Portsmouth	B+	80.7	43K	14
30	Newton	B+	80.1	533	111
31	Newmarket	B	79.3	5K	239
32	Durham	B	78.8	16K	55
33	Farmington	B	77.5	3K	17
34	Epping	B	76.7	2K	106
35	Pembroke	B	75.8	5K	84
36	Hudson	B	75.4	17K	68
37	Bennington	B	75.4	1K	73
38	Wilton	B	75.2	2K	28
39	Tilton	B-	74.4	1K	254
40	Henniker	B-	73.8	3K	70
41	Woodstock	B-	73.8	3K	24
42	Lebanon	B-	72.9	10K	128
43	Newfields	B-	72.7	550	22
44	Troy	B-	71.5	1K	52
45	Hinsdale	B-	71.2	3K	231
46	Newport	B-	71.1	5K	168
47	Hampstead	B-	71	7K	96
48	Gorham	B-	70.9	3K	64
49	Waterville Valley	B-	70.6	3K	13
50	Laconia	C+	69.7	21K	94
51	Northumberland	C+	69.3	3K	43
52	Seabrook	C+	68.2	14K	221
53	Sunapee	C+	67.3	2K	82
54	Plainfield	C+	66.9	1K	182
55	Wolfeboro	C+	66.8	6K	129
56	New Castle	C+	66.7	910	29
57	Pittsfield	C+	66.6	2K	124
58	Colebrook	C+	66.6	1K	69
59	Brentwood	C+	66.5	1K	7
60	Sandown	C+	66	1K	187
61	New London	C+	65.7	3K	110
62	Rollinsford	C+	65.6	2K	47
63	Franconia	C+	65.4	1K	120
64	Ashland	C+	65.3	2K	105
65	Lisbon	C	64.9	1K	65
66	Warner	C	64.7	878	28
67	Plymouth	C	64.2	7K	255
68	Northwood	C	64.1	996	118
69	Winchester	C-	59.5	3K	62
70	Northfield	C-	59.5	3K	188
71	Meredith	C-	59.4	5K	292
72	Allenstown	C-	59.4	1K	58
73	Charlestown	C-	58.1	3K	217
74	Stow	C-	56.8	1K	284
75	Jackson	C-	55.6	755	92
76	Swanzey	D+	53.3	3K	291
77	Bethlehem	D+	51.8	2K	65
78	Concord	D+	51.3	44K	63
79	Kingston	D+	51.2	627	16
80	Manchester	D+	50.9	124K	20
81	Wakefield	D+	50.1	2K	78
82	Greenville	D	48.9	2K	153
83	Walpole	D	48.7	2K	210
84	Madison	D	47.6	1K	61
85	Salem	D	47.4	22K	292
86	Epsom	D	47.3	2K	99
87	Haverhill	D	46.7	4K	246
88	Alton	D	46.1	2K	214
89	Goffstown	D	45.9	5K	61
90	Hillsborough	D	45.9	3K	224
91	Bartlett	D	45.1	8K	555
92	Milford	F	43	10K	195
93	Conway	F	42.8	12K	597
94	Rochester	F	42.5	26K	317
95	Derry	F	42.5	21K	390
96	Raymond	F	40.2	5K	154
97	Canaan	F	40.1	1K	121
98	Andover	F	39.9	650	89
99	Londonderry	F	39	9K	605
100	Weare	F	38.9	599	259
101	Windham	F	38.4	3K	169
102	Exeter	F	37.5	14K	203
103	Danville	F	36.5	1K	249
104	Stratham	F	36	2K	387
105	Freedom	F	35.1	975	160
106	Pelham	F	35	2K	220
107	Enfield	F	33.2	2K	211
108	Tamworth	F	32	966	417
109	Gilford	F	31	4K	1030
110	Barrington	F	31	2K	619
111	Belmont	F	30	4K	444
112	Campton	F	30	3K	532
113	Plaistow	F	30	2K	382
114	Hopkinton	F	29	2K	119
115	Ossipee	F	29	2K	791
116	Loudon	F	28	948	374
117	New Hampton	F	28	666	133
118	Thornton	F	27.1	1K	355
119	Moultonborough	F	27	3K	627

Counties

Browse New Hampshire counties

Belknap 8 cities · avg 53.3 Carroll 10 cities · avg 43.1 Cheshire 8 cities · avg 70.1 Coos 6 cities · avg 76.8 Grafton 17 cities · avg 61.9 Hillsborough 17 cities · avg 67.6 Merrimack 15 cities · avg 61.6 Middlesex 1 city · avg 56.8 Rockingham 23 cities · avg 59.3 Strafford 7 cities · avg 67 Sullivan 7 cities · avg 74.4

ZIP Codes

Browse New Hampshire by ZIP code

Look up water quality by ZIP code to find the systems serving your area.

View all New Hampshire ZIP codes →

FAQ

Frequently asked questions about New Hampshire's water

Is New Hampshire's tap water safe to drink?

New Hampshire's water quality varies by city. The statewide average grade is C (62.3/100). 41% of cities scored an A or B, while 37% received a D or F. Check your specific city for detailed results.

Which New Hampshire cities have the best water quality?

The top-rated cities are Litchfield (A), Claremont (A), Antrim (A-). These cities scored highest based on violation history, lead levels, PFAS contamination, and regulatory compliance.

Which New Hampshire cities have the worst water quality?

The lowest-rated cities are Moultonborough (F), Thornton (F), New Hampton (F). We recommend residents in these areas consider water filtration and review their city's specific contaminant data.

How many New Hampshire cities have PFAS in their water?

21 out of 119 cities tested positive for PFAS "forever chemicals" (18%). 15 cities exceed the 2024 EPA maximum contaminant levels. Reverse osmosis or activated carbon filters can help reduce PFAS exposure.

Do any New Hampshire cities have dangerous lead levels?

58 cities exceed the EPA lead action level of 15 ppb. Lead contamination typically comes from aging pipes and lead service lines rather than the water source itself. An NSF 53-certified filter can effectively remove lead from tap water.

New Hampshire Water Quality Report