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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
51–75 of 131Cogswell Springs Water Works
NH1121010 · 3,000 served
Little Pond Estates
NH0192080 · 3,000 served
Woodstock Water Dept
NH2571020 · 2,950 served
Charlestown Water Works
NH0411010 · 2,850 served
Winchester Water Dept
NH2531010 · 2,800 served
Conway Water and Sewer
NH0511010 · 2,745 served
Groveton Water Sys
NH1781010 · 2,650 served
Gorham Water and Sewer Dept
NH0921010 · 2,630 served
Lancaster Water Dept
NH1291010 · 2,500 served
Tilton Northfield Water Dist
NH2351010 · 2,500 served
Locke Lake
NH0142010 · 2,280 served
Woodsville Water and Light
NH1101040 · 2,075 served
Paradise Shores
NH1612010 · 2,060 served
Hillsborough Water Works
NH1141010 · 2,000 served
Alton Water Works
NH0061010 · 1,800 served
North Hinsdale Water Dept
NH1151010 · 1,800 served
Wilton Water Works
NH2521010 · 1,790 served
Bethlehem Village Dist
NH0241010 · 1,750 served
N Swanzey Water and Fire Prct
NH2301010 · 1,700 served
Rollinsford Water Sewer Dist
NH2011010 · 1,688 served
Sunapee Water Works
NH2271010 · 1,680 served
Whitefield Water
NH2501010 · 1,640 served
Pittsfield Aqueduct
NH1911010 · 1,630 served
Belmont Water Dept
NH0201010 · 1,612 served
Epping Water and Sewer Dept
NH0761010 · 1,600 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