Well water in Harwich, Massachusetts
In Harwich, none of 140 tested well samples exceeded the EPA limit for nitrate, based on public data from USGS Water Quality Portal.
The strongest signal is coliform bacteria: Recommended for every private well, every year, too few samples to carry the headline but first on the test list below.
501 test results across 7 contaminants from at least 20 wells, 1972 to 1985; chloride has the most at 144. 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 Harwich. 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 |
|---|---|---|---|---|---|---|
| Nitrate 1972 to 1985 | 140 | 99% | 0.1 | 1.3 | 10 mg/L EPA limit | |
| Copper 1982 to 1984 | 21 | 95% | 0.05 | 0.12 | 1.3 mg/L EPA limit | |
| Chloride 1972 to 1985 | no limit | 144 | 100% | 16 | 12,000 | 250 mg/L nuisance level |
| Sodium 1972 to 1985 | no limit | 136 | 100% | 10 | 19 | 20 mg/L health guideline |
| Iron 1975 to 1985 | no limit | 31 | 48% | 0 | 1,700 | 300 ug/L nuisance level |
| Manganese 1975 to 1984 | no limit | 25 | 84% | 20 | 320 | 300 ug/L health guideline |
Sampled fewer than 10 times, too few to summarize: Fluoride (4).
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 contaminants with a federal limit, no tested sample in Harwich came back above it. That is reassuring, but sampling is uneven: wells that were never tested are not in this data.
Chloride and Manganese 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 Harwich
- 1Coliform bacteriaRecommended for every private well, every year.
- 2NitrateRecommended for every private well, especially near farms or septic systems.
- 3ChlorideDetected in 100% of local samples.
- 4CopperDetected in 95% of local samples.
- 5ManganeseDetected in 84% of local samples.
- 6FluorideDetected in 75% of local samples.
- 7PFAS1 unlined landfill on record locally.
- 8Volatile organic compounds (VOCs)1 unlined landfill on record locally.
- 9Metals panel2 hazardous waste sites on record locally.
Test your Harwich well for coliform bacteria, nitrate and chloride
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 Harwich numbers, $29. Every line explained, ranked by what matters, with the fix for each.
Wells in Harwich
163 domestic wells in Harwich are on record with the state since 1978. 0% are drilled into bedrock, and the typical well is 45 feet deep (one in ten goes past 73 feet).
In a typical Harwich 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 Harwich
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 Harwich
MassDEP records 1 unlined landfill and 2 hazardous waste sites in Harwich, 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.
- 12
- registered underground storage tank sitesRegistered tanks are regulated and inspected; they matter most when they are old or near a shallow well.
Treatment that fits the local profile
Manganese
Oxidizing filter (greensand, birm) whole-house; Water softener (low levels); Point-of-use reverse osmosis
Iron
Oxidizing filter whole-house; Water softener (low levels); Aeration plus filtration
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 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.
Free, no obligation
Get on the list for a free in-home water test in Harwich
No water treatment company serves Harwich 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 Harwich, and you get an email naming it first.
Common questions
How deep are wells in Harwich?
The typical domestic well in Harwich is 45 feet deep, based on 163 wells reported to the state since 1978. One in ten is deeper than 73 feet. 0% are drilled into bedrock.
How often should I test a private well in Harwich?
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 Harwich
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: 501 samples in Harwich. 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: 361 well records in Harwich, 163 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 Harwich. 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.