What is radon and why does it matter?

Radon is a naturally occurring radioactive gas that seeps into buildings from soil. It is the second-leading cause of lung cancer in the United States after smoking. The EPA action level is 4.0 pCi/L — at or above that, mitigation is recommended.

Who can legally test for or fix radon in New Jersey?

New Jersey requires radon testing and mitigation businesses to be certified by the NJDEP Radon Program — measurement and mitigation are separate certifications. Every company in this directory appears in the official certification list.

How much does radon testing and mitigation cost?

A professional radon test in NJ typically costs about $100–$300. If levels are high, a mitigation system usually runs about $800–$2,500 installed, depending on the home’s foundation.

Certified radon testing companies in New Jersey

New Jersey certifies every radon measurement and mitigation business through the NJDEP Radon Program, and assigns each municipality a radon-potential tier. This page lists companies from the official certification list.

✓ Source: https://njems.nj.gov/DataMiner/Search/SearchByCategory?isExternal=y&getCategory=y&catName=Radon; https://dep.nj.gov/rpp/radon/radon_bus/ — registry last retrieved 2026-07-17. 29 companies listed, including 10 certified out-of-state providers that serve New Jersey. Inclusion is a matter of public record, not an endorsement — verify current status with the state.

Radon risk in New Jersey: NJDEP classifies 137 municipalities as Tier 1 (high radon potential), 241 as Tier 2 (moderate), and 159 as Tier 3 (low). Testing is recommended for every home regardless of tier. Every Tier 1 town has its own page with published NJDEP test data — find yours below.

Tier 1 (high radon) towns — published test data by municipality

Burlington County: Chesterfield Township · Mansfield Township · Washington Township

Camden County: Lawnside Borough · Magnolia Borough · Runnemede Borough · Somerdale Borough

Cumberland County: Bridgeton City · Greenwich Township · Lawrence Township · Upper Deerfield Township

Gloucester County: Deptford Township · East Greenwich Township · Greenwich Township · Harrison Township · South Harrison Township · Swedesboro Borough · Wenonah Borough · Woolwich Township

Hunterdon County: Alexandria Township · Bethlehem Township · Bloomsbury Borough · Califon Borough · Clinton Town Clinton Township · Delaware Township · East Amwell Township · Flemington Borough · Franklin Township · Frenchtown Borough · Glen Gardner Borough · Hampton Borough · High Bridge Borough · Holland Township · Kingwood Township · Lambertville City · Lebanon Borough and Lebanon Township · Milford Borough · Raritan Township · Readington Township · Stockton Borough · Tewksbury Township · West Amwell Township

Mercer County: Ewing Township · Hopewell Borough and Hopewell Township and Pennington Borough · Lawrence Township · Princeton Boro and Princeton Township

Middlesex County: Highland Park Borough · North Brunswick Township · Piscataway Township

Monmouth County: Allentown Borough and Upper Freehold Township · Colts Neck Township · Freehold Borough and Freehold Township · Holmdel Township · Little Silver Borough · Marlboro Township · Millstone Township · Roosevelt Borough · Shrewsbury Borough Shrewsbury Township

Morris County: Chester Borough and Chester Township · Dover Town · Harding Township · Jefferson Township · Kinnelon Borough · Long Hill Township (Passaic Township) · Mendham Borough and Mendham Township · Mine Hill Township · Morris Plains Borough · Morris Township and Morristown Town · Mount Olive Township · Randolph Township · Riverdale Borough · Roxbury Township · Victory Gardens Borough · Washington Township · Wharton Borough

Passaic County: Pompton Lakes Borough · West Milford Township

Salem County: Mannington Township · Pilesgrove Township · Woodstown Borough

Somerset County: Bernards Township · Bernardsville Borough · Branchburg Township · Bridgewater Township · Far Hills Borough · Franklin Township · Hillsborough Township · Millstone Borough · Montgomery Township · Peapack Gladstone Borough · Rocky Hill Borough · Somerville Borough · Warren Township · Watchung Borough

Sussex County: Andover Borough and Andover Township · Branchville Borough · Byram Township and Stanhope Borough · Frankford Township · Franklin Borough · Fredon Township · Green Township · Hamburg Borough · Hampton Township · Hardyston Township · Hopatcong Borough · Lafayette Township · Montague Township · Newton Town · Ogdensburg Borough · Sandyston Township · Sparta Township · Stillwater Township · Sussex Borough · Vernon Township · Walpack Township · Wantage Township

Warren County: Allamuchy Township · Alpha Borough · Belvidere Township · Blairstown Township · Franklin Township · Frelinghuysen Township · Greenwich Township · Hackettstown Town · Hardwick Township · Harmony Township · Hope Township · Independence Township · Knowlton Township · Liberty Township · Lopatcong Township · Mansfield Township · Oxford Township · Phillipsburg Town · Pohatcong Township · Washington Borough and Washington Township · White Township

Browse by county

Sussex County
3 certified companies
Camden County
2 certified companies
Middlesex County
2 certified companies
Somerset County
2 certified companies
Bergen County
1 certified company
Burlington County
1 certified company
Gloucester County
1 certified company
Hudson County
1 certified company
Hunterdon County
1 certified company
Mercer County
1 certified company
Monmouth County
1 certified company
Morris County
1 certified company
Passaic County
1 certified company
Warren County
1 certified company

Certified companies (29)

Company	Location	County	Certifications	Credential Score	License #
Advanced Radon Services, LLC	Hardwick, NJ	Warren	mitigation	43	MIB94174
Better Homes & Business Remodeling LLC	Stockholm, NJ	Sussex	mitigation	43	MIB95879
Breeze, LLC	Indianapolis, IN	—	measurement	49	MEB95756
Certified Environmental Contractors, LLC	Freehold, NJ	Monmouth	measurementmitigation	78	MEB94012, MIB93612
Clean Vapor Newco LLC Dba Clean Vapor	Mooresville, NC	Iredell	mitigation	43	MIB92520
Eai Inc	Jersey City, NJ	Hudson	mitigation	43	MIB95929
Ecosense, Inc.	San Jose, CA	—	measurement	56	MEB95795
Emsl Analytical, Inc.	Cinnaminson, NJ	Burlington	measurement	49	MEB92525
Eurofins Environment Testing Radon, LLC	Carrollton, TX	—	measurement	49	MEB90095
Fran The Radon Man, LLC	Mantua, NJ	Gloucester	measurementmitigation	78	MEB93928, MIB92743
Hera Environmental LLC	Cherry Hill, NJ	Camden	measurementmitigation	87	MEB93466, MIB93466
Home Total Service Ltd (Hts Ltd)	Pluckemin, NJ	Somerset	mitigation	43	MIB93296
Jersey Radon LLC	Bridgewater, NJ	Middlesex	mitigation	43	MIB94281
North Jersey Radon Services, LLC	Newton, NJ	Sussex	mitigation	43	MIB95961
Obar Systems Inc.	Newfoundland, NJ	Passaic	mitigation	58	MIB90013
Pro-Lab	Weston, FL	—	measurement	56	MEB92046
Professional Radon Systems, Inc	Paramus, NJ	Bergen	measurementmitigation	87	MEB90026, MIB90026
Radata, LLC	Flanders, NJ	Morris	measurementmitigation	85	MEB90001, MIB90001
Radon Removal Nj LLC	Milltown, NJ	Middlesex	mitigation	43	MIB93677
Radon Shield LLC	Trenton, NJ	Mercer	mitigation	43	MIB93374
Radonova	Lombard, IL	—	measurement	49	MEB93550
Rock-Well Environmental Inc.	Somerdale, NJ	Camden	mitigation	43	MIB90104
Rtca - Radon Testing Corp. of America, Inc.	Elmsford, NY	—	measurement	56	MEB90036
Safe Air Systems Radon Mitigation	Lebanon, NJ	Hunterdon	mitigation	43	MIB93320
Soos Radon & Electric, Inc	Hillsborough, NJ	Somerset	mitigation	43	MIB90027
Spruce Environmental Technologies, Inc.	Ward Hill, MA	—	measurement	78	MEB90122
The Lab Environmental	Pound Ridge, NY	—	measurement	56	MEB95808
Trc Engineers, Inc.	Windsor, CT	—	measurement	64	MEB95799
Tristate Radon Services	Stanhope, NJ	Sussex	mitigation	58	MIB95832

Before you hire anyone

Most directories only tell you who to call. These are the cases where the honest answer is that you may not need this service at all, and the mistakes that cost people the most money.

When you probably don’t need this

You have a current certified test below the action level. — If the result is recent and the buyer or lender accepts it, you are done. Radon does not need re-testing on a schedule the way a tank or a septic system needs servicing.Details →
You only want to know for yourself. — A DIY kit is adequate for personal knowledge and costs a fraction of a professional test. Certification matters when the result has to satisfy somebody else.Details →
You already have a working system and a passing follow-up test. — A functioning system is not a defect to re-negotiate. The fan is a wear item, not a reason to re-mitigate.Details →

What goes wrong

The test is invalidated by how it was run. — Closed-house conditions, placement and duration all matter. A test taken with windows open, or in the wrong spot, produces a number nobody should act on — and in a sale it can have to be redone under time pressure.Details →
A system is installed and never re-tested. — Installation is not proof of a result. The follow-up test is what shows the system actually worked.Details →
The well is never tested. — Radon in air and radon in well water are separate problems with separate fixes. An air system does nothing for waterborne radon.Details →

Typical radon testing pricing, with sources: what this costs in NJ →