Well water in Sherborn, Massachusetts
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Testing strongly recommended
private wells tested between 2020 and 2023 in Sherborn had PFOA above the EPA limit (4 ng/L), according to MassDEP.
43 private wells tested 2020 to 2023 in state summaries; 13 test results across 7 contaminants from at least 2 wells, 1970 to 1982; fluoride has the most at 2. 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.
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 Sherborn who sent a sample to the state lab, the health-based limits most often exceeded were PFOA (42% of 43 wells) and PFOS (33% of 43 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 Sherborn
- 1PFOA42% of 43 local wells tested were above the EPA limit.
- 2PFOS33% of 43 local wells tested were above the EPA limit.
- 3Coliform bacteriaRecommended for every private well, every year.
- 4NitrateRecommended for every private well, especially near farms or septic systems.
- 5FluorideDetected in 100% of local samples.
- 6IronDetected in 100% of local samples.
- 7ChlorideDetected in 100% of local samples.
- 8ManganeseDetected in 100% of local samples.
- 9PFAS1 unlined landfill on record locally.
- 10Volatile organic compounds (VOCs)1 unlined landfill on record locally.
- 11Metals panel1 hazardous waste site on record locally.
Test your Sherborn well for PFOA, PFOS and coliform bacteria
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 Sherborn numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Sherborn
506 domestic wells in Sherborn are on record with the state since 1915. 84% are drilled into bedrock, and the typical well is 325 feet deep (one in ten goes past 700 feet).
In a typical Sherborn well, bedrock starts about 18 feet down, the median yield is 7 gallons per minute, 14% 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 Sherborn
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 Sherborn
MassDEP records 1 unlined landfill and 1 hazardous waste site in Sherborn, among 5 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.
- 2
- other remediation projects
Treatment that fits the local profile
PFOA
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
PFOS
Granular activated carbon whole-house; Point-of-use reverse osmosis; Anion exchange
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 PFOS
Aquasana Claryum 3-Stage under-sink filter
under-sink or countertop, about $175
Certified to NSF/ANSI 53 to reduce 99% of lead and 99.7% of PFOA and PFOS at the tap. Not a fix for arsenic, nitrate or bacteria.
For PFOS
Aquasana HealthShield whole-house filter
whole-house, at the point of entry, about $2,099
Whole-house carbon system the maker certifies to reduce PFAS (PFOA and PFOS) and VOCs at every tap; a UV option adds bacteria protection.
Free, no obligation
Get on the list for a free in-home water test in Sherborn
No water treatment company serves Sherborn 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 Sherborn, and you get an email naming it first.
Common questions
How deep are wells in Sherborn?
The typical domestic well in Sherborn is 325 feet deep, based on 506 wells reported to the state since 1915. One in ten is deeper than 700 feet. 84% are drilled into bedrock.
How often should I test a private well in Sherborn?
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 Sherborn
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: 13 samples in Sherborn. 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 Sherborn, up to 43 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: 594 well records in Sherborn, 506 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: 5 regulated sites located in Sherborn. 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.