New York county well guide

Well Water in Suffolk County, NY: Testing, Contractors and Rules

About 31,718 households in Suffolk County, 5% of the county, rely on a private well. Nobody tests that water unless the owner does.

Labs within 40 milesLicensed contractors
5%of households on a private well
Share on wells, county vs state
Suffolk County5%
New York average25%
28licensed contractors serve the county
5 mito the nearest certified lab, Long Island Analytical Laboratories, Inc
Nostatewide test required when a home is sold

Roughly 5% of Suffolk County households, about 31,718, get their water from a private well rather than a utility. They are concentrated in the rural parts of the county, and they are on their own for testing.

Local rules for wells in Suffolk County

Private wells in Suffolk County follow New York's statewide rules, administered by NYS Department of Environmental Conservation. No water test is required by the state when a new well is completed. There is no statewide test requirement when a home is sold, though lenders often ask for one. The cards below show the details and the official sources.

At a glance

Water test for a new wellNot required statewide

No single statewide rule. The driller must be DEC-registered, file a preliminary notice before drilling, disinfect the finished well under NYSDOH Appendix 5-B, and send a well completion report to DEC and to you within 30 days. NYSDOH says a new well should be tested before use for coliform bacteria, nitrate, nitrite, arsenic, lead, iron, manganese, sodium, hardness, pH and turbidity. Many county health departments (Westchester, Rockland, Putnam, Dutchess, Suffolk and others) require a permit and a passing water test before a new well can be used.

Water test when a home is soldNot required statewide

No statewide requirement. A few counties and towns require a well test or well inspection when a property changes hands, and FHA, VA and USDA loans usually ask for a bacteria and nitrate test. Check with the county health department.

What the state recommends

NYSDOH recommends a coliform bacteria test every year, plus a first-time panel of nitrate, nitrite, arsenic, lead, iron, manganese, sodium, sulfate, hardness, pH, alkalinity and turbidity, then periodic re-testing of whatever showed up. Add radon, uranium, methane or PFAS where they are known in your area.

Free or low-cost testingAvailable

No statewide free program. Several county health departments run their own ELAP-certified labs and sell low-cost bacteria and nitrate tests (Erie, Monroe, Suffolk, Nassau, Cattaraugus, Chautauqua, Allegany). Others keep a list of local certified labs.

Getting your water tested near Suffolk County

7 certified labs within 40 miles serve Suffolk County, starting with Long Island Analytical Laboratories, Inc in Holbrook (about 5 miles from the county center). Each card below shows whether the lab takes homeowner samples and which tests it is certified for.

7 certified labs within 40 miles

Licensed well contractors serving Suffolk County

28 licensed contractors serve Suffolk County, including A. Casola Service LLC and AARCO Environmental Services. Each profile carries the state license number and the date we checked it, and the filters below sort them by drilling, pump work or treatment.

Well depth and water chemistry

Wells in Suffolk County typically reach 100 to 400 ft in bedrock across most of upstate; 30 to 150 ft in glacial sand and gravel valleys and on Long Island feet. What comes up with the water depends on the aquifer, and across New York the usual suspects are coliform bacteria, nitrate (farm valleys and older septic areas), arsenic (parts of central and western new york), iron and manganese. A first full panel tells you which of them apply to your well.

Typical well depth

Varies by location. Check the state well record search for logs of nearby wells.

Contaminants to test for
  • Coliform bacteria
  • Nitrate (farm valleys and older septic areas)
  • Arsenic (parts of central and western New York)
  • Iron and manganese
  • Hardness (limestone country)
  • Sodium and chloride (road salt)
  • Sulfate and hydrogen sulfide (shale areas)
  • Radon and uranium (Southern Tier and Adirondack bedrock)
  • Methane (Southern Tier shale)
  • PFAS (Hoosick Falls
  • Newburgh and other hot spots)
  • Barium and fluoride (western New York)

Neighboring counties: Westchester County, Putnam County, Rockland County, Dutchess County.

What well work costs in Suffolk County

Basic bacteria and nitrate test$25 to $75lab fee, homeowner sample
Full panel lab test$150 to $400metals, VOCs, radiologicals
Well inspection$250 to $550flow, pressure, visual, water test
Submersible pump replacement$1,200 to $4,500parts and labor
Pressure tank replacement$400 to $1,200installed
Whole-house treatment system$800 to $6,000softener, iron filter, UV, RO
New well drilled$5,500 to $25,000about $25 to $65 per foot
Shock chlorination$80 to $300or about $20 as a DIY job

National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.

Questions Suffolk County well owners ask

How many homes in Suffolk County are on a well?

About 31,718, or 5% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.

Where is the closest certified lab to Suffolk County?

Long Island Analytical Laboratories, Inc in Holbrook, about 5 miles away. Call first to ask whether they accept homeowner samples.

Do I need a permit to drill a well in Suffolk County?

No single statewide rule. The driller must be DEC-registered, file a preliminary notice before drilling, disinfect the finished well under NYSDOH Appendix 5-B, and send a well completion report to DEC and to you within 30 days. NYSDOH says a new well should be tested before use for coliform bacteria, nitrate, nitrite, arsenic, lead, iron, manganese, sodium, hardness, pH and turbidity. Many county health departments (Westchester, Rockland, Putnam, Dutchess, Suffolk and others) require a permit and a passing water test before a new well can be used.

What does a well test cost near Suffolk County?

A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. Mail-in kits cost about the same as walking in.