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New Hampshire Water Quality
131
Utilities in database
0.8M
Residents served
55%
On private wells
2
Key contaminants tracked
Drinking Water in New Hampshire
New Hampshire has 131 community water systems serving approximately 0.8 million residents. Primary water sources include groundwater. The most commonly reported contaminants include disinfection byproducts, nitrates. 55% of New Hampshire residents rely on private wells. DES holds primary enforcement authority under the Safe Drinking Water Act.
Utilities in New Hampshire
101–125 of 131Carroll Water Works
NH0381010 · 875 served
Ossipee Water Dept
NH1841010 · 860 served
Bear View Crossing
NH0043050 · 800 served
Epsom Village Water District
NH0771010 · 800 served
Milton Water Dist
NH1581010 · 800 served
Mountain Lakes Water District
NH1101050 · 787 served
Bennington Water Dept
NH0211010 · 775 served
Meriden Village Water Dist
NH1921020 · 750 served
Marlborough Water Works
NH1481010 · 750 served
No Haverhill Water and Light
NH1101020 · 750 served
River Run Condos
NH0162170 · 750 served
Vlg of Northwood Rdg Wtr Dist
NH1792030 · 688 served
Canaan Water Dept
NH0351010 · 684 served
Warner Village Water Dist
NH2411010 · 660 served
Andover Village Dist
NH0081010 · 650 served
Bartlett Village Pct
NH0161010 · 625 served
Sullivan County Complex
NH2384010 · 625 served
N Walpole Village District/low
NH2401020 · 625 served
Green Hills Ests
NH1973030 · 620 served
Campton Village Pct
NH0341010 · 600 served
New Hampton Village Pct
NH1691010 · 600 served
Hill Water Works
NH1131010 · 600 served
Lov Water
NH0862010 · 590 served
Newfields Vlg Water and Sewer
NH1681010 · 550 served
Birch Hill East
NH0512010 · 550 served
Key Contaminant Concerns in New Hampshire
Nitrates
Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always from human activity — nitrate interferes with the blood's ability to carry oxygen. The United States produces over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination.
DBPs
When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.
New Hampshire Water FAQs
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Data source: Utility data from EPA SDWIS. 131 active community water systems ingested. CCR contaminant data ingestion in progress.
Last updated: 2026-04-22