Well water in Randolph, New Hampshire
In Randolph, 20% of 30 private wells tested between 2006 and 2020 had uranium above the New Hampshire guidance level (30 ug/L), according to NH DHHS.
33 private wells tested 2006 to 2020 in state summaries; 6 individual samples from 6 wells, 1988 to 1992. Data refreshed September 3, 2026.
Separately, a USGS and NHDES statistical model puts the chance that a bedrock well in Randolph exceeds 5 ug/L of arsenic at 2% (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.
| Contaminant | Wells tested | Above state level | Median | 95th pct | Highest | State level | |
|---|---|---|---|---|---|---|---|
| Lead (stagnant) | 21 | 33% | 5.5 | 82.7 | 721 | 15 ug/L | |
| Iron | 29 | 31% | 100 | 7,800 | 22,000 | 300 ug/L | |
| Copper (stagnant) | 21 | 29% | 0.3 | 2.9 | 3.2 | 1.3 mg/L | |
| Sodium | 29 | 21% | 6.6 | 34.3 | 54.6 | 20 mg/L | |
| Uranium | 30 | 20% | 10.5 | 53.8 | 64 | 30 ug/L | |
| Manganese | 29 | 7% | 0 | 1,800 | 3,000 | 300 ug/L | |
| Fluoride | 33 | 0% | 0.3 | 2.4 | 2.8 | 4 mg/L | |
| Nitrate | 31 | 0% | 0.1 | 0.6 | 1.1 | 10 mg/L | |
| Nitrite | 31 | 0% | 0 | 0 | 0 | 1 mg/L | |
| Chloride | 30 | 0% | 7.5 | 140 | 191 | 250 mg/L | |
| Arsenic | 30 | 0% | 0.7 | 0.7 | 0.7 | 5 ug/L |
Get the free Randolph well report
One email with the numbers above, what they mean for a home in Randolph, exactly which tests to order, and what treatment fits the local profile. No spam, unsubscribe in one click.
What this means
Among homeowners in Randolph who sent a sample to the state lab, the health-based limits most often exceeded were lead (33% of 21 wells), copper (29% of 21 wells), and uranium (20% of 30 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.
Iron and sodium 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 Randolph
- PFAS1 unlined landfill on record locally.
- Volatile organic compounds (VOCs)1 unlined landfill on record locally.
- Lead33% of 21 local wells tested were above the New Hampshire guidance level.
- Iron31% of 29 local wells tested were above the New Hampshire guidance level.
- Copper29% of 21 local wells tested were above the New Hampshire guidance level.
- Sodium21% of 29 local wells tested were above the New Hampshire guidance level.
- Uranium20% of 30 local wells tested were above the New Hampshire guidance level.
- Manganese7% of 29 local wells tested were above the New Hampshire guidance level.
- Coliform bacteriaRecommended for every private well, every year.
- RadonMedian local reading is 17,000 pCi/L.
Wells in Randolph
153 domestic wells in Randolph are on record with the state since 1984. 99% are drilled into bedrock, and the typical well is 302 feet deep (one in ten goes past 618 feet).
In a typical Randolph well, bedrock starts about 15 feet down, the median yield is 8 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.
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.
Contamination sources on record in Randolph
NHDES records 1 unlined landfill in Randolph, among 6 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
- unlined landfillOlder unlined landfills are a leading source of PFAS, VOCs and metals in nearby wells.
- 1
- registered underground storage tank siteRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 4
- 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
- Uranium
- Point-of-use reverse osmosis; Anion exchange; Whole-house anion exchange
- Iron
- Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
- Sodium
- Point-of-use reverse osmosis; Distillation
- Fluoride
- Point-of-use reverse osmosis; Activated alumina; Distillation
Book a free water test in Randolph
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.
Common questions
How deep are wells in Randolph?
The typical domestic well in Randolph is 302 feet deep, based on 153 wells reported to the state since 1984. One in ten is deeper than 618 feet. 99% are drilled into bedrock.
Is there arsenic in well water in Randolph?
Arsenic was detected in 0% of 1 public well samples in Randolph, 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 Randolph?
The median radon level across 5 public samples in Randolph was 17,000 pCi/L, with a high of 78,000 pCi/L. New Hampshire recommends treatment above 2,000 pCi/L.
How often should I test a private well in Randolph?
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: 42 samples in Randolph. 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 11 contaminants in Randolph, up to 33 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: 157 well records in Randolph, 153 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: 6 regulated sites located in Randolph. 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.