Well water in Seabrook, New Hampshire
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Testing strongly recommended
tested well samples in Seabrook exceeded the EPA limit for arsenic (10 ug/L), based on public data from USGS Water Quality Portal.
739 test results across 15 contaminants from at least 3 wells, 1987 to 2019; manganese has the most at 94. Data refreshed September 3, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
Separately, a USGS and NHDES statistical model puts the chance that a bedrock well in Seabrook exceeds 5 ug/L of arsenic at 60% (as low as 39% in parts of town), based on geology rather than tests.
What individual samples found
Each row summarizes every public sample for that contaminant inside Seabrook. 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.
| Contaminant | Above limit | Samples | Detected | Median | Highest | Limit |
|---|---|---|---|---|---|---|
| Arsenic 1987 to 2019 | 93 | 99% | 4.6 | 23.7 | 10 ug/L EPA limit | |
| Fluoride 1987 to 2019 | 93 | 98% | 0.07 | 0.1 | 4 mg/L EPA limit | |
| Nitrate 2014 to 2019 | 88 | 51% | 0.068 | 2.66 | 10 mg/L EPA limit | |
| Uranium 2014 to 2019 | 48 | 98% | 2.62 | 3.4 | 30 ug/L EPA limit | |
| Lead 1987 to 2019 | 16 | 6% | 0 | 0.195 | 15 ug/L EPA limit | |
| Copper 1987 to 2019 | 16 | 44% | 0 | 0.002 | 1.3 mg/L EPA limit | |
| Manganese 1987 to 2019 | no limit | 94 | 100% | 115 | 175 | 300 ug/L health guideline |
| Iron 1987 to 2019 | no limit | 94 | 98% | 214 | 327 | 300 ug/L nuisance level |
| Chloride 1987 to 2019 | no limit | 93 | 100% | 49.9 | 105 | 250 mg/L nuisance level |
| Sodium 1987 to 2019 | no limit | 93 | 100% | 38.7 | 45.7 | 20 mg/L health guideline |
Sampled fewer than 10 times, too few to summarize: Radium (226 + 228) (4), PFOS (2), PFOA (2), E. coli (1), Radon (2).
Closer than the town
See the sampled wells near your address
The same records, drawn around one point: which wells within a few miles were sampled and what they found, how deep the wells next to you were drilled, and any leaking tank or cleanup site within a mile.
Check my addressWhat this means
The contaminants most often above their limit here are arsenic (48% of 93 samples). A well next door can differ sharply from yours because bedrock fractures, well depth and plumbing all matter, so these rates describe the area, not your tap.
Manganese, Iron, and Chloride are widespread in local groundwater. They are mainly a staining and taste problem, but high manganese also carries a health advisory for infants.
What to test for in Seabrook
- 1Arsenic48% of 93 local samples were above the limit.
- 2Coliform bacteriaRecommended for every private well, every year.
- 3RadonMedian local reading is 1,225 pCi/L.
- 4NitrateRecommended for every private well, especially near farms or septic systems.
- 5ManganeseDetected in 100% of local samples.
- 6ChlorideDetected in 100% of local samples.
- 7IronDetected in 98% of local samples.
- 8Volatile organic compounds (VOCs)11 leaking underground storage tank sites on record locally.
- 9PFAS1 unlined landfill on record locally.
- 10Metals panel7 hazardous waste sites on record locally.
Test your Seabrook well for arsenic, coliform bacteria and radon
Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.
Order the Tap Score well water test kit, from $209Already tested? Upload the report
Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.
Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.
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Where to get a well tested in New Hampshire: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Seabrook numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Seabrook
60 domestic wells in Seabrook are on record with the state since 1999. 92% are drilled into bedrock, and the typical well is 230 feet deep (one in ten goes past 507 feet).
In a typical Seabrook well, bedrock starts about 35 feet down, the median yield is 16 gallons per minute, 11% 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.
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.
- Open NHDES OneStop and choose Water Well.
- 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.
- 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.
- 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.
The rock under Seabrook
Not a principal aquifer
The USGS map places this area outside any principal aquifer, which usually means wells here draw from fractured bedrock or thin local deposits rather than a large regional aquifer. Bedrock wells of that kind are where arsenic, radon and uranium turn up, and yields vary from well to well.
Classification from the USGS Principal Aquifers of the United States (national map, 2003 edition, GIS release 2015), read at the town centroid. A single well can sit in a different unit, especially near a boundary.
Official help in New Hampshire
Two places to start that are not selling anything: the state program that answers private well questions, and its list of labs certified to run drinking water tests. A certified lab is the difference between a result you can act on and a number.
Contamination sources on record in Seabrook
NHDES records 11 leaking underground storage tank sites, 1 unlined landfill, 7 hazardous waste sites, and 12 reported spills and releases in Seabrook, among 187 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.
- 11
- leaking underground storage tank sitesGasoline 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.
- 7
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 12
- reported spills and releasesMost spills are fuel; a few are solvents or chemicals that reach the water table.
- 24
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 59
- locally identified potential contamination sourcesTowns inventory these (vehicle repair, labs, salt piles, farms) when they draw wellhead protection maps.
- 71
- other remediation projects
- 2
- other solid waste facilities
Treatment that fits the local profile
Arsenic
Point-of-use reverse osmosis; Adsorptive media (iron-based) whole-house; Anion exchange
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Systems we would look at first
Some links below are affiliate links. If you buy through one, the merchant pays us a commission at no extra cost to you. It does not change which products we list or what the data says.
For arsenic
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For arsenic
Whole-house arsenic and uranium filter
whole-house, at the point of entry, about $2,500
Adsorptive iron-based media; sized to your well yield.
For arsenic
Aquasana SmartFlow reverse osmosis
under-sink or countertop, about $225
Certified to NSF/ANSI 58 and 53 to reduce arsenic (96%, pentavalent), fluoride (90%), lead (99%), nitrate, nitrite and PFOA/PFOS at the kitchen tap, with a remineralizer.
For manganese
Iron and manganese oxidizing filter
whole-house, at the point of entry, about $1,800
Air-injection or greensand media; fixes staining at the source.
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Common questions
How deep are wells in Seabrook?
The typical domestic well in Seabrook is 230 feet deep, based on 60 wells reported to the state since 1999. One in ten is deeper than 507 feet. 92% are drilled into bedrock.
Is there arsenic in well water in Seabrook?
Arsenic was detected in 99% of 93 public well samples in Seabrook, and 48% 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 often should I test a private well in Seabrook?
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.
Towns near Seabrook
Closest first. Groundwater does not stop at a line on a map, so the next town over is a fair second opinion.
Want the numbers themselves? Download the New Hampshire dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 739 samples in Seabrook. 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: modeled chance (60%) that a well in Seabrook exceeds 5 ug/L of arsenic, from geology rather than tests. 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. Retrieved September 3, 2026.
- NHDES Water Well Inventory: 174 well records in Seabrook, 60 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: 187 regulated sites located in Seabrook. 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.