Well Water in Concord Area, New Hampshire

Merrimack County · Population ~44,000 (Concord); surrounding towns ~20,000 · Aquifer: Glacial Till / Bedrock / Merrimack River Valley

Hardness: Moderate to Hard

The Concord area includes the state capital and its surrounding bedroom communities of Bow, Hopkinton, and Dunbarton. While Concord proper has a public water system, many homes in the surrounding towns rely entirely on private wells. The area's bedrock geology produces the classic NH contaminant profile: arsenic, radon, and uranium from granitic and metamorphic formations.

Arsenic in the Capital Region

The Concord area sits on a mix of granitic, metamorphic, and sedimentary bedrock. The NH Geological Survey has mapped arsenic probability across the region, and many surrounding towns show moderate to high risk.

Bow, Hopkinton, and Dunbarton — all heavily dependent on private wells — have documented arsenic exceedances. The bedrock type varies significantly across the area, creating high well-to-well variability. Your neighbor's test results tell you nothing about your well.

See our arsenic guide for the full picture on NH arsenic.

Radon and Uranium

Central NH's bedrock produces elevated radon and uranium in groundwater. The same radioactive decay chain that creates radon in your basement also dissolves into your well water.

When radon-containing water is used for showering, dishwashing, or laundry, the gas is released into indoor air — contributing to your total radon exposure. This is a cancer risk that many homeowners don't think about.

Test your water for radon if you haven't already, especially if your home also has elevated indoor air radon (which is very common in central NH). See our radon guide.

Manganese

Manganese is common in NH groundwater and is frequently elevated in the Concord area. While primarily an aesthetic concern at lower levels (black staining, metallic taste), manganese at higher concentrations is a health concern, particularly for infants and children.

The EPA has a lifetime health advisory of 300 µg/L for manganese, but health effects can occur at lower levels in young children. If your water stains fixtures black or has a metallic taste, test for manganese.

Testing Recommendations

If you're on a well in the Concord area, test for: arsenic, radon, uranium, manganese, bacteria, nitrates, hardness, pH, and conductivity.

For treatment options and NH rebates (up to $5,000-$10,000), see our resources page.

NH Treatment Rebates: If your well water exceeds any health-based standards, you may be eligible for $5,000-$10,000 in state rebates toward a treatment system. Check your eligibility.

Every well is different. Two wells on the same street can produce completely different water. The data on this page reflects documented conditions in the Concord Area area, but the only way to know what's in your water is to test it.

Sources

  • NH Geological Survey — Arsenic and Uranium in Merrimack County Wells
  • USGS — Trace Elements in Groundwater of New Hampshire
  • NH DES — Private Well Testing Data for Central NH