Well Water Nerd

Well water in Conway, New Hampshire

In Conway, 3% of 116 tested private well samples exceeded the EPA limit for nitrate (10 mg/L), based on public data from USGS Water Quality Portal.

73 private wells tested 2006 to 2020 in state summaries; 116 individual samples from 53 wells, 1984 to 2022. Data refreshed September 3, 2026.

Separately, a USGS and NHDES statistical model puts the chance that a bedrock well in Conway exceeds 5 ug/L of arsenic at 6% (as low as 0% 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
Uranium3832%12.810230030 ug/L
Sodium3123%10.510617220 mg/L
Fluoride7310%1.74.3144 mg/L
Chloride336%2.5178327250 mg/L
Iron313%100200500300 ug/L
Arsenic333%0.73.165 ug/L
Manganese320%0100100300 ug/L
Nitrate260%0.11.44.810 mg/L
Nitrite260%000.21 mg/L

What individual samples found

Each row summarizes every public sample for that contaminant inside Conway. Above limit means above the EPA maximum contaminant level; where EPA has no enforceable limit, the row shows a health guideline or nuisance level instead.

ContaminantSamplesDetectedAbove limitMedianHighestLimit
Fluoride
1985 to 2021
1283%17%1.069.84 mg/L
EPA limit
Copper
1992 to 2022
1070%10%0.0022.151.3 mg/L
EPA limit
Nitrate
1984 to 2021
11686%3%0.51410 mg/L
EPA limit
Arsenic
1992 to 2022
1040%0%04.210 ug/L
EPA limit
Lead
1992 to 2022
1060%0%0.1232.0315 ug/L
EPA limit
Manganese
1984 to 2022
7786%no limit602,500300 ug/L
health guideline
Sodium
1984 to 2021
73100%no limit818020 mg/L
health guideline
Chloride
1984 to 2021
7397%no limit14240250 mg/L
nuisance level

Sampled fewer than 10 times, too few to summarize: Uranium (7), Radium (226 + 228) (4), E. coli (2), PFOA (1), PFOS (1), Iron (3), Radon (1).

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What this means

Among homeowners in Conway who sent a sample to the state lab, the health-based limits most often exceeded were uranium (32% of 38 wells), fluoride (10% of 73 wells), and arsenic (3% of 33 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.

Sodium exceeds the state's advisory level in a sizable share of wells; this is mostly a taste, staining or diet issue rather than a toxicity one.

What to test for in Conway

  • Volatile organic compounds (VOCs)30 leaking underground storage tank sites on record locally.
  • PFAS2 unlined landfills on record locally.
  • Metals panel6 hazardous waste sites on record locally.
  • Uranium32% of 38 local wells tested were above the New Hampshire guidance level.
  • Sodium23% of 31 local wells tested were above the New Hampshire guidance level.
  • Copper10% of 10 local samples were above the limit.
  • Chloride6% of 33 local wells tested were above the New Hampshire guidance level.
  • Nitrate3% of 116 local samples were above the limit.
  • Iron3% of 31 local wells tested were above the New Hampshire guidance level.
  • Arsenic3% of 33 local wells tested were above the New Hampshire guidance level.
  • Coliform bacteriaRecommended for every private well, every year.

Wells in Conway

475 domestic wells in Conway are on record with the state since 1984. 95% are drilled into bedrock, and the typical well is 500 feet deep (one in ten goes past 980 feet).

In a typical Conway well, bedrock starts about 72 feet down, the median yield is 8 gallons per minute, 24% 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.

35
1980s
35
1990s
121
2000s
188
2010s
96
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 Conway

NHDES records 30 leaking underground storage tank sites, 2 unlined landfills, 6 hazardous waste sites, and 7 reported spills and releases in Conway, among 303 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.

30
leaking underground storage tank sitesGasoline and heating oil that leaked from tanks move through groundwater as benzene, MTBE and other volatile organic compounds.
2
unlined landfillsOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
6
hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
7
reported spills and releasesMost spills are fuel; a few are solvents or chemicals that reach the water table.
85
registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
33
locally identified potential contamination sourcesTowns inventory these (vehicle repair, labs, salt piles, farms) when they draw wellhead protection maps.
1
lined landfill or transfer facility
138
other remediation projects
1
other solid waste facility

Treatment that fits the local profile

Uranium
Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
Fluoride
Point-of-use reverse osmosis; Activated alumina; Distillation
Sodium
Point-of-use reverse osmosis; Distillation
Chloride
Point-of-use reverse osmosis; Distillation
Copper
Neutralizing filter to raise pH; Point-of-use reverse osmosis
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation

Book a free water test in Conway

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 Conway?

The typical domestic well in Conway is 500 feet deep, based on 475 wells reported to the state since 1984. One in ten is deeper than 980 feet. 95% are drilled into bedrock.

Is there arsenic in well water in Conway?

Arsenic was detected in 40% of 10 public well samples in Conway, and 0% were above the EPA limit of 10 ug/L. Arsenic has no taste or smell; a lab test is the only way to know your level.

How high is radon in well water in Conway?

The median radon level across 1 public samples in Conway was 3,740 pCi/L, with a high of 3,740 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.

How often should I test a private well in Conway?

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: 400 samples in Conway. 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 9 contaminants in Conway, up to 73 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: 570 well records in Conway, 475 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: 303 regulated sites located in Conway. 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.