Well Water Nerd

Well water in Center Harbor, New Hampshire

In Center Harbor, 18% of 68 private wells tested between 2006 and 2020 had lead above the New Hampshire guidance level (15 ug/L), according to NH DHHS.

104 private wells tested 2006 to 2020 in state summaries; 2 individual samples from 1 wells, 1988 to 1993. Data refreshed September 3, 2026.

Separately, a USGS and NHDES statistical model puts the chance that a bedrock well in Center Harbor exceeds 5 ug/L of arsenic at 44% (as low as 20% in parts of town), based on geology rather than tests.

What homeowner tests found

NH DHHS WISDOM private well summaries: private wells tested and reported to the state, 2006 to 2020. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.

ContaminantWells testedAbove state levelMedian95th pctHighestState level
Sodium8049%19.12521,33520 mg/L
Lead
(stagnant)
6818%1.732.219515 ug/L
Iron7917%01,0002,700300 ug/L
Radon2711%69025223,2002,000 pCi/L
Chloride9511%14399820250 mg/L
Copper
(stagnant)
687%0.125.51.3 mg/L
Arsenic825%0.74.4115 ug/L
Manganese794%0100700300 ug/L
Nitrate1040%0.13.56.810 mg/L
Nitrite1040%0001 mg/L
Fluoride890%0.32.42.94 mg/L
Uranium790%0.73430 ug/L

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What this means

Among homeowners in Center Harbor who sent a sample to the state lab, the health-based limits most often exceeded were lead (18% of 68 wells), copper (7% of 68 wells), and arsenic (5% of 82 wells). These are ordinary wells tested by their owners, so the shares are the best available picture of a typical well here, with one caveat: people test more often when they suspect a problem.

Radon was above the New Hampshire guidance level of 2,000 pCi/L in 11% of 27 wells. Radon in water matters because it moves into indoor air during showers and laundry.

Sodium, iron, and chloride exceed the state's advisory level in a sizable share of wells; these are mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in Center Harbor

  • Volatile organic compounds (VOCs)1 leaking underground storage tank site on record locally.
  • PFAS1 unlined landfill on record locally.
  • Sodium49% of 80 local wells tested were above the New Hampshire guidance level.
  • Lead18% of 68 local wells tested were above the New Hampshire guidance level.
  • Iron17% of 79 local wells tested were above the New Hampshire guidance level.
  • Radon11% of 27 local wells tested were above the New Hampshire guidance level.
  • Chloride11% of 95 local wells tested were above the New Hampshire guidance level.
  • Copper7% of 68 local wells tested were above the New Hampshire guidance level.
  • Arsenic5% of 82 local wells tested were above the New Hampshire guidance level.
  • Manganese4% of 79 local wells tested were above the New Hampshire guidance level.

Wells in Center Harbor

297 domestic wells in Center Harbor are on record with the state since 1984. 100% are drilled into bedrock, and the typical well is 445 feet deep (one in ten goes past 806 feet).

In a typical Center Harbor well, bedrock starts about 12 feet down, the median yield is 7.75 gallons per minute, 23% of wells yield under 3 gallons per minute and usually need a storage tank.

Bedrock wells are where arsenic, uranium and radon come from: the water sits in fractures in granite and metamorphic rock and picks up whatever the rock carries. That is why testing for those three matters more here than in a dug or gravel well.

40
1980s
43
1990s
112
2000s
58
2010s
44
2020s

Find your own well's report

The state keeps the driller's report for most wells drilled since 1984. It tells you how deep your well is, where bedrock starts, and how much water it makes, which decides what treatment can work.

  1. Open NHDES OneStop and choose Water Well.
  2. Enter your town and one word of your street name. Leave out the house number and the Road or Street part; a short search matches more.
  3. In the results, click Show for your address to see the report: total depth, depth to bedrock, casing, yield in gallons per minute, static water level, and the driller.
  4. Save Results exports the whole list to a spreadsheet.

Reports exist only for wells drilled since January 1984, when reporting became mandatory, and street names are as they were when the well was drilled.

Contamination sources on record in Center Harbor

NHDES records 1 leaking underground storage tank site and 1 unlined landfill in Center Harbor, among 20 regulated sites in total. Groundwater does not follow property lines, so a well within a few hundred feet of one of these is worth testing for what that site could release.

1
leaking underground storage tank siteGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
1
unlined landfillOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
2
registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
1
locally identified potential contamination sourceTowns inventory these (vehicle repair, labs, salt piles, farms) when they draw wellhead protection maps.
15
other remediation projects

Treatment that fits the local profile

Lead
Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching
Copper
Neutralizing filter to raise pH; Point-of-use reverse osmosis
Radon
Aeration (bubble-up or diffused) whole-house; Granular activated carbon whole-house (lower levels only)
Sodium
Point-of-use reverse osmosis; Distillation
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Fluoride
Point-of-use reverse osmosis; Activated alumina; Distillation

Book a free water test in Center Harbor

A licensed local water treatment company tests your tap water in your home, walks you through the numbers, and quotes treatment only if something needs fixing. Free, about 30 minutes, no obligation.

What are you worried about?

The test is free and there is no obligation. Your details go only to the company named above, and we log the time and address of this request.

Common questions

How deep are wells in Center Harbor?

The typical domestic well in Center Harbor is 445 feet deep, based on 297 wells reported to the state since 1984. One in ten is deeper than 806 feet. 100% are drilled into bedrock.

How often should I test a private well in Center Harbor?

Test for bacteria and nitrate every year. Test once for arsenic, uranium, radon, fluoride, manganese and PFAS, then again every three to five years or after any change in taste, color, or plumbing.

Sources

  • USGS Water Quality Portal: 7 samples in Center Harbor. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
  • NH DHHS WISDOM private well summaries: summaries for 12 contaminants in Center Harbor, up to 104 wells each. Town summaries of private well tests run by the New Hampshire Public Health Laboratories, published by NH DHHS through the WISDOM environmental public health tracking portal. Exceedance shares use New Hampshire guidance levels, which are stricter than EPA for arsenic (5 ug/L), manganese (0.3 mg/L), radon (2,000 pCi/L) and sodium (20 mg/L). Statistics for small counts are suppressed (*). Retrieved September 3, 2026.
  • NHDES Water Well Inventory: 318 well records in Center Harbor, 297 domestic. Well construction records reported to the New Hampshire Department of Environmental Services Water Well Board. Only aggregates are shown; owner names and addresses are never stored. Retrieved September 3, 2026.
  • NHDES OneStop regulated sites: 20 regulated sites located in Center Harbor. Remediation sites, underground storage tanks, solid waste facilities and potential contamination sources from the New Hampshire Department of Environmental Services OneStop database. Retrieved September 3, 2026.

Non-detects count as samples and are treated as zero when computing medians. Exactly at the limit counts as not above it. A sample belongs to the town containing the well's reported coordinates.