privatewelldata / States / Massachusetts

Massachusetts well water testing

34 labs are listed on Massachusetts’s official certified-lab list; 7% of 472 sampled wells were above the arsenic limit across 12 counties. Updated 2026-10-18.

Official lab list for Massachusetts

Coverage map

Map of Massachusetts: 17 listed labs open to private wells shown as dots, and 12 counties shaded by the share of sampled wells above the arsenic limit.
● 17 listed labs open to private wells (placed by town or postal code). Counties shaded by share of sampled wells above 10 µg/L arsenic: 0 1–5% 5–10% 10–25% 25–50% 50%+ grey = no data. Sources: MassDEP; USGS/EPA Water Quality Portal; US Census boundaries · privatewelldata.com

Where the labs are

32 rows · showing 1–25

Listed labs by town. Source: MassDEP · privatewelldata.com
TownLabs
Mansfield3
Norwell1
Agawam1
Albany1
Aquinnah1
Attleboro1
Ayer1
Barnstable1
Belchertown1
Charleston1
Danvers1
Dayville1
Derry1
East Longmeadow1
Gloucester1
Jamaica Plain1
Melville1
Middleboro1
Milford1
New Bedford1
North Swanzey1
Salem1
South Bend1
Tampa1
Warwick1
West Warwick1
Westborough1
Westwood1
Wilmington1
Winthrop1
Woburn1
Ypsilanti1

Tests these labs are listed for

  • Bacteria (coliform / E. coli): 17 of 34 labs
  • Radioactivity: 8 of 34 labs

Counted from the tests each lab is certified for on the official list. A lab may offer more; ask before you send a sample.

Well water results by county

12 rows

Share of sampled wells above the EPA limit. Source: USGS/EPA Water Quality Portal · privatewelldata.com
CountyArsenic > 10 µg/LNitrate > 10 mg/L
Barnstable County2% of 1235% of 1,705
Berkshire County0% of 100% of 108
Bristol County0% of 184% of 25
Essex County0% of 133% of 70
Franklin County–4% of 53
Hampden County4% of 244% of 69
Hampshire County0% of 170% of 24
Middlesex County3% of 296% of 156
Nantucket County–7% of 14
Norfolk County3% of 330% of 73
Plymouth County0% of 752% of 131
Worcester County22% of 1301% of 126

Nitrate: 4% of 2,554 sampled wells statewide. All Massachusetts counties →

Labs on the MassDEP list

31 rows · showing 1–25

  • Vallid Laboratories Inc., AgawamListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Adirondack Environmental Services, Inc., AlbanyListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Wampanoag Environmental Laboratory, AquinnahListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Attleboro Water Dept, AttleboroListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Nashoba Analytical, AyerListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Barnstable County Water Quality Laboratory, BarnstableListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Quabbin Analytical Laboratory, BelchertownListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • GEL Laboratories, LLC, CharlestonListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Northeast Environmental Laboratory, Inc., DanversListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Microbac Laboratories, Inc., DayvilleListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Granite State Analytical Services LLC, DerryListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Contest, A Pace Analytical Laboratory, East LongmeadowListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Biomarine, GloucesterListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • MA State Public Health Laboratory, Jamaica PlainListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Alpha Analytical, LLC, MansfieldListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Pace Analytical Services, LLC- Melville, NY, MelvilleListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Analytical Balance, MiddleboroListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • ProVerde Environmental, Inc., MilfordListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • New Bedford Health Department Laboratory, New BedfordListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Nelson Analytical Lab, Keene Division, North SwanzeyListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • New England Chromachem, SalemListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Eurofins Eaton Analytical, LLC, South BendListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • KNL Environmental Testing, LLC, TampaListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • RI Analytical, WarwickListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • New England Testing Laboratory, West WarwickListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Alpha Analytical, LLC, WestboroughListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Whitelodge Laboratory, WestwoodListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Enthalpy Analytical, LLC, WilmingtonListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • MWRA Central Laboratory, WinthropListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • Practical Applications, WoburnListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)
  • National Testing Laboratories, LTD, YpsilantiListed in MassDEP’s certified lab list. See the official list → (checked 2026-10-17)

See all 3 Massachusetts lab listings →

How to choose a lab

  1. Pick a lab on the official list above that is certified for each test you need (bacteria and chemistry are often separate certifications).
  2. Ask for the lab’s own sample bottles and instructions; bacteria samples usually must reach the lab within 24–30 hours.
  3. Compare prices for a basic package (bacteria, nitrate, pH/TDS) and add arsenic or other metals where local data shows a risk.
  4. Be wary of free in-home tests from treatment-system sellers — see our salesperson checklist.

Based on CDC and EPA private-well guidance.

Questions

Where can I get my well water tested in Massachusetts?

Use a lab on Massachusetts’s official certified-lab list. We count 34 listed labs (excluding those marked as serving public water systems only), most in Mansfield, Norwell, Agawam. Confirm the lab is certified for the exact tests you need before you send a sample.

What should I test my well for in Massachusetts?

Test every year for bacteria (total coliform and E. coli), nitrate, pH and total dissolved solids (CDC). In Massachusetts, 7% of sampled wells with arsenic data were above the EPA limit, so include arsenic. Use our test helper for a list that fits your home.

Is there well water data for my county in Massachusetts?

Yes for 12 counties: we show the share of sampled wells above the EPA arsenic and nitrate limits, from the Water Quality Portal (USGS/EPA). These are monitoring wells as well as private wells, so test your own well.

Get a test list for your home → · If a result is high