Well water in Sandwich, Massachusetts
1in2
Testing strongly recommended
tested well samples in Sandwich exceeded the EPA limit for PFOA (4 ng/L), based on public data from USGS Water Quality Portal.
2,181 test results across 12 contaminants from at least 166 wells, 1948 to 2025; nitrate has the most at 597. Data refreshed September 3, 2026.
Compiled by Nick at Well Water Nerd from public records. How these pages are built
What individual samples found
Each row summarizes every public sample for that contaminant inside Sandwich. 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 |
|---|---|---|---|---|---|---|
| PFOA 2021 | 52 | 100% | 1,460 | 13,700 | 4 ng/L EPA limit | |
| PFOS 2021 | 52 | 87% | 3,060 | 20,800 | 4 ng/L EPA limit | |
| Nitrate 1948 to 2025 | 597 | 89% | 0.9 | 146 | 10 mg/L EPA limit | |
| Lead 1976 to 2006 | 101 | 10% | 0 | 20 | 15 ug/L EPA limit | |
| Fluoride 1948 to 1998 | 181 | 65% | 0.1 | 1.5 | 4 mg/L EPA limit | |
| Copper 1983 to 2006 | 99 | 33% | 0 | 0.105 | 1.3 mg/L EPA limit | |
| Arsenic 1976 to 2008 | 27 | 93% | 0.78 | 1.8 | 10 ug/L EPA limit | |
| Uranium 2006 | 14 | 7% | 0 | 0.02 | 30 ug/L EPA limit | |
| Iron 1948 to 2008 | no limit | 303 | 65% | 10.4 | 20,000 | 300 ug/L nuisance level |
| Manganese 1956 to 2008 | no limit | 291 | 83% | 24.6 | 1,100 | 300 ug/L health guideline |
| Chloride 1948 to 1998 | no limit | 268 | 100% | 17.5 | 1,900 | 250 mg/L nuisance level |
| Sodium 1967 to 1998 | no limit | 196 | 100% | 11 | 54 | 20 mg/L health guideline |
Over time
Share of samples above the limit by period. A cell needs ten samples to show; a comparison needs twenty in each period. Later periods sample fewer wells, and often the ones already known to have a problem.
| Contaminant | before 2000 | 2000s | 2010s | 2020s |
|---|---|---|---|---|
| Nitrate | 18%451 samples | 7%96 samples | n/a | 0%50 samples |
| Lead | 3%87 samples | 0%14 samples | n/a | n/a |
| Copper | 0%85 samples | 0%14 samples | n/a | n/a |
Nitrate above the limit in Sandwich fell from 7% of 96 samples in the 2000s to 0% of 50 in the 2020s.
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 pfoa (100% of 52 samples), pfos (87% of 52 samples), and nitrate (15% of 597 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.
Iron, Manganese, 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 Sandwich
- 1PFOA100% of 52 local samples were above the limit.
- 2PFOS87% of 52 local samples were above the limit.
- 3Nitrate15% of 597 local samples were above the limit.
- 4Lead3% of 101 local samples were above the limit.
- 5Coliform bacteriaRecommended for every private well, every year.
- 6ChlorideDetected in 100% of local samples.
- 7ManganeseDetected in 83% of local samples.
- 8PFAS1 unlined landfill on record locally.
- 9Volatile organic compounds (VOCs)1 unlined landfill on record locally.
- 10Metals panel2 hazardous waste sites on record locally.
Test your Sandwich well for PFOA, PFOS 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.
Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.
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 Sandwich numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Sandwich
596 domestic wells in Sandwich are on record with the state since 1914. 0% are drilled into bedrock, and the typical well is 75 feet deep (one in ten goes past 120 feet).
In a typical Sandwich well, the median yield is 15 gallons per minute.
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 Sandwich
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 Sandwich
MassDEP records 1 unlined landfill and 2 hazardous waste sites in Sandwich, among 15 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.
- 2
- hazardous waste sitesSolvents, degreasers and metals from industrial sites can travel far in fractured bedrock.
- 9
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
- 3
- 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
Nitrate
Point-of-use reverse osmosis; Anion exchange; Distillation
Lead
Point-of-use reverse osmosis; Certified lead-removal carbon filter; Neutralizing filter to raise pH and stop leaching
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 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.
For lead
Acid neutralizing filter
whole-house, at the point of entry, about $1,200
Raises pH so plumbing stops leaching lead and copper.
Free, no obligation
Get on the list for a free in-home water test in Sandwich
No water treatment company serves Sandwich 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 Sandwich, and you get an email naming it first.
Common questions
How deep are wells in Sandwich?
The typical domestic well in Sandwich is 75 feet deep, based on 596 wells reported to the state since 1914. One in ten is deeper than 120 feet. 0% are drilled into bedrock.
Is there arsenic in well water in Sandwich?
Arsenic was detected in 93% of 27 public well samples in Sandwich, 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 often should I test a private well in Sandwich?
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 Sandwich
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: 2,181 samples in Sandwich. 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 well completion reports: 732 well records in Sandwich, 596 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: 15 regulated sites located in Sandwich. 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.