Well water in Bolton, Massachusetts
In Bolton, chloride was detected in 100% of 84 tested well samples from USGS Water Quality Portal.
The strongest signal is PFOA: 24% of 25 local wells tested were above the EPA limit, too few samples to carry the headline but first on the test list below.
25 private wells tested 2020 to 2023 in state summaries; 261 test results across 6 contaminants from at least 16 wells, 1963 to 1976; chloride has the most at 84. Data refreshed September 16, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
MassDEP offered free PFAS tests to towns without public water and to wells near suspected sources such as landfills, fire stations and airports, so these shares describe the wells that took part rather than every well in town.
What homeowner tests found
MassDEP Private Well PFAS Sampling Program: private wells tested and reported to the state, 2020 to 2023. Shares are against the level the state applies to each contaminant, named in the last column; several are stricter than EPA.
What individual samples found
Each row summarizes every public sample for that contaminant inside Bolton. 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 |
|---|---|---|---|---|---|---|
| Chloride 1963 to 1976 | no limit | 84 | 100% | 165 | 560 | 250 mg/L nuisance level |
| Sodium 1963 to 1976 | no limit | 84 | 100% | 54 | 200 | 20 mg/L health guideline |
| Iron 1963 to 1976 | no limit | 59 | 100% | 30,000 | 260,000 | 300 ug/L nuisance level |
| Manganese 1963 to 1976 | no limit | 30 | 100% | 4,100 | 54,000 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: Nitrate (3), Fluoride (1).
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
Among homeowners in Bolton who sent a sample to the state lab, the health-based limits most often exceeded were PFOA (24% of 25 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.
What to test for in Bolton
- 1PFOA24% of 25 local wells tested were above the EPA limit.
- 2Coliform bacteriaRecommended for every private well, every year.
- 3NitrateRecommended for every private well, especially near farms or septic systems.
- 4FluorideDetected in 100% of local samples.
- 5ChlorideDetected in 100% of local samples.
- 6IronDetected in 100% of local samples.
- 7ManganeseDetected in 100% of local samples.
- 8PFAS1 unlined landfill on record locally.
- 9Volatile organic compounds (VOCs)1 unlined landfill on record locally.
- 10Metals panel1 hazardous waste site on record locally.
Test your Bolton well for PFOA, coliform bacteria and nitrate
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 Massachusetts: certified labs, state programs and prices.
Already have results back? Get your lab report read against the Bolton numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Bolton
419 domestic wells in Bolton are on record with the state since 1915. 86% are drilled into bedrock, and the typical well is 305 feet deep (one in ten goes past 600 feet).
In a typical Bolton well, bedrock starts about 16 feet down, the median yield is 12 gallons per minute, 7% 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 MassDEP Well Location Viewer and choose Water Well.
- The completion report lists total depth, depth to bedrock, static water level, yield and the driller.
Drillers have filed completion reports with the state since 1984; the viewer's public copy is refreshed a few times a year.
The rock under Bolton
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 Massachusetts
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.
- Private Wells, MassDEP
- Certified Laboratories, MassDEP
Contamination sources on record in Bolton
MassDEP records 1 unlined landfill and 1 hazardous waste site in Bolton, among 3 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
- hazardous waste siteSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 1
- registered underground storage tank siteRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
Treatment that fits the local profile
PFOA
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
Chloride
Point-of-use reverse osmosis; Distillation
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Systems we would look at first
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For PFOA
Under-sink reverse osmosis system
under-sink or countertop, about $300
Look for NSF/ANSI 58 certification listing the contaminant you need removed.
For PFOA
Whole-house PFAS carbon system
whole-house, at the point of entry, about $3,000
Granular activated carbon certified to NSF/ANSI 53 for PFOA and PFOS; replace media on schedule.
For PFOA
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 iron
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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Get on the list for a free in-home water test in Bolton
No water treatment company serves Bolton through Well Water Nerd yet. We are signing licensed companies on county by county: they test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Leave your details and you are first in line. Nothing is shared until a company joins for Bolton, and you get an email naming it first.
Common questions
How deep are wells in Bolton?
The typical domestic well in Bolton is 305 feet deep, based on 419 wells reported to the state since 1915. One in ten is deeper than 600 feet. 86% are drilled into bedrock.
How often should I test a private well in Bolton?
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 Bolton
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 Massachusetts dataset as CSV, every county and town, with the sources named.
Sources
- USGS Water Quality Portal: 261 samples in Bolton. Data from the Water Quality Portal, a service of USGS, EPA and USDA; groundwater samples collected by USGS and cooperators. Retrieved September 3, 2026.
- MassDEP Private Well PFAS Sampling Program: summaries for 4 contaminants in Bolton, up to 25 wells each. Private well PFAS results from the Massachusetts Department of Environmental Protection free sampling program, 2020 to 2023, one anonymized row per well. Shares are against the EPA limit for each compound (4 ng/L for PFOA and PFOS, 10 ng/L for PFHxS and PFNA). Massachusetts applies its own PFAS6 standard of 20 ng/L to the sum of six compounds; that sum is not a contaminant page here. Zero means not detected. Retrieved September 16, 2026.
- MassDEP well completion reports: 537 well records in Bolton, 419 domestic. Well completion reports filed with the Massachusetts Department of Environmental Protection, as published in the Well Location Viewer (April 2023 vintage). Only aggregates are shown; owner names and addresses are never stored. Retrieved September 16, 2026.
- MassDEP regulated sites: 3 regulated sites located in Bolton. Chapter 21E release sites, solid waste landfills and underground storage tank facilities from the Massachusetts Department of Environmental Protection, through MassGIS. Retrieved September 16, 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.