How to Hire a DEP-Certified Radon Contractor in Pennsylvania: The Complete Verification Guide

The Contractor Problem Nobody Talks About

Pennsylvania has hundreds of companies advertising radon mitigation services. A meaningful percentage of them are not DEP-certified. Some are general contractors who added radon to their service menu after a brief online course. Some are HVAC companies who installed a fan on a pipe and called it mitigation. Some hold outdated certifications that lapsed without renewal. None of them are doing anything that would be obvious from their website.

PA Code Title 25, Chapter 240 — the Radon Certification Act — requires that anyone performing radon mitigation services in Pennsylvania for compensation hold an active DEP certification. The penalty for non-compliance exists on paper. Enforcement is complaint-driven. The practical result: homeowners who don't verify certification are relying entirely on a contractor's word that they're qualified to do the work.

This guide gives you the exact verification process, the questions to ask before signing any contract, and the red flags that indicate you're talking to a contractor who doesn't meet Pennsylvania's standard.

What DEP Certification Requires

DEP certification under Chapter 240 is not a registration or a license-by-default. A mitigation contractor must complete an approved training course covering radon physics, measurement methods, system design, installation standards per ANSI/AARST CCAH, and Pennsylvania-specific regulatory requirements. They must pass a written examination. They must carry liability insurance. And they must renew their certification on a schedule that requires continued education.

There are two primary DEP contractor categories relevant to residential homeowners: Radon Mitigation Contractor (RMC) — authorized to design and install mitigation systems — and Radon Testing Contractor (RTC) — authorized to perform measurement services. A contractor may hold both certifications or just one.

For post-mitigation testing to be valid as a legal or transaction document, it must be performed by a DEP-certified RTC — not by the same RMC who installed the system, and not by the homeowner. This separation of measurement from installation is a conflict-of-interest protection that matters in real estate transactions, school compliance documentation, and any context where the result may be scrutinized.

National certifications — from NRPP (National Radon Proficiency Program) or NRSB (National Radon Safety Board) — are recognized training pathways that DEP accepts for certification purposes. Holding an NRPP or NRSB credential is not itself equivalent to DEP certification, but contractors with current national credentials have met training standards that exceed what uncertified contractors typically carry.

How to Verify Certification in Two Minutes

PA DEP maintains a publicly searchable database of currently certified radon professionals at dep.pa.gov. The search is free, requires no account, and returns active certification status for any contractor by name or certification number. This lookup takes approximately two minutes and eliminates any ambiguity about a contractor's current standing.

The process: navigate to dep.pa.gov, find the Bureau of Radiation Protection's Radon Division page, and use the certified contractor search function. Search by contractor name or business name. The result will show certification type — RMC, RTC, or both — certification number, and expiration date. If a contractor's name does not appear, or if their certification shows as expired, they do not have current authorization to perform paid radon work in Pennsylvania.

When a contractor provides their certification number verbally or in a contract, verify it independently. A certificate on a wall or a logo on a website is not verification — the DEP database is verification. Contractors who object to this process or become defensive when you mention it are providing useful information about their professionalism.

The Pre-Installation Diagnostic: What It Is and Why It's Non-Negotiable

A DEP-certified contractor who provides a quote for radon mitigation without performing or scheduling a pre-installation diagnostic is giving you a price estimate, not a system design. The diagnostic is the process by which a contractor determines the specific technical approach for your specific structure — and in Pennsylvania's diverse housing stock, that determination is not trivial.

A proper diagnostic includes: identification of foundation type and condition, sub-slab communication testing at multiple points using a vacuum gauge and test holes, identification of all potential radon entry routes including sump pits, floor drains, utility penetrations, and wall-floor joints, assessment of the HVAC system's pressure relationship to the basement, and documentation of any features that would complicate standard ASD installation.

The diagnostic typically adds one to two hours to a site visit and may or may not be billed separately depending on the contractor's business model. Some contractors offer free diagnostics as part of the quotation process. Others bill a diagnostic fee of $75 to $150 that applies toward the installation cost if you proceed.

A contractor who quotes based on square footage alone — without visiting the property or reviewing foundation plans — cannot provide a defensible system design. In complex Pennsylvania foundations, an under-designed system will fail post-mitigation testing, requiring additional work at additional cost.

Red Flags and Questions to Ask Every Contractor

Hiring a radon mitigation contractor follows the same pattern as hiring any skilled trade professional — the quality of the conversation before you sign the contract predicts the quality of the work. There are specific questions and specific responses that separate qualified contractors from those who will cost you more money in the long run.

Questions to ask every contractor, with the answers a qualified contractor will give:

What is your DEP certification number, and can I verify it at dep.pa.gov? A certified contractor will provide the number immediately and encourage the verification.

Will you perform a pre-installation diagnostic before designing the system? Yes — and they'll describe the sub-slab communication test and entry point assessment.

What fan model do you plan to install, and why is it appropriate for my foundation type? A qualified contractor will reference specific fan models and explain the selection based on your sub-slab conditions.

Who will perform the post-mitigation test, and are they a separate DEP-certified RTC? Yes, and they'll name the testing contractor or explain their protocol for independent post-test.

Red flags: contractors who cannot immediately provide a DEP certification number, contractors who quote a system without asking about your foundation type, contractors who offer to perform both the installation and the post-mitigation test with the same person, contractors who guarantee a specific post-mitigation result before doing a diagnostic.

Using PA Radon Hub to Find and Verify Certified Contractors

PA Radon Hub was built to solve one specific problem: the gap between a homeowner who has a radon test result requiring action and the DEP-certified professionals who can resolve it. That gap is real — it manifests as homeowners who can't quickly identify which contractors in their area hold current DEP certification, and as contractors who can't efficiently reach homeowners in their service area who need their services.

Our contractor listings are matched to Pennsylvania city pages using PA DEP's certified contractor database. Every contractor in the PA Radon Hub directory has been verified against active DEP certification records. When you submit a lead form or call through a PA Radon Hub city page, you are reaching a contractor whose DEP certification was current at the time of verification.

We are an independent informational resource — not a mitigation company, not a government agency, and not affiliated with PA DEP. We do not perform testing or mitigation. Our function is to reduce friction in the connection between homeowners and certified professionals, and to provide the geological and regulatory context that makes that connection informed rather than arbitrary.

Verify any contractor's DEP certification independently at dep.pa.gov, regardless of how you found them. Retain all documentation — DEP certification number, installation records, test results. And retest annually, because a mitigation system that was working last year may not be performing at the same level this year.

The statewide awareness event that SB 760 will generate in 2026–2027 will increase residential testing demand across Pennsylvania. Scheduling mitigation work before that awareness wave fully drives contractor demand is a practical advantage for homeowners who act now.

Pennsylvania's radon problem is geological. It is permanent, it is measurable, and it is solvable. PA Radon Hub exists to help every Pennsylvania homeowner get from the problem to the solution as directly as possible.

PA Radon Hub is an independent informational resource. We do not perform radon testing or mitigation. We are not affiliated with PA DEP. Verify any contractor's DEP certification independently at dep.pa.gov regardless of how you found them.