How to Hire a DEP-Certified Radon Mitigation Contractor in Pennsylvania: The Complete Checklist

Why DEP Certification Is a Legal Requirement, Not a Preference

Pennsylvania's radon contractor certification program is not voluntary credentialing — it is a legal mandate with teeth. The Radon Certification Act (Act 43 of 1987) established Pennsylvania's certification program more than 35 years ago, making it one of the oldest state-level radon contractor certification programs in the country. The act was a direct legislative response to the 1984 Stanley Watras incident in Limerick Township, Berks County, where a nuclear plant construction worker repeatedly triggered radiation alarms upon entering his workplace — not from the plant, but from radon emanating from the Reading Prong geology beneath his home. That single incident catalyzed Pennsylvania into being the first state in the nation to comprehensively regulate the radon industry. Homeowners in Allentown, Reading, Pittsburgh, and Scranton — all in EPA Zone 1 — should verify certification before signing any mitigation contract.

PA Code § 240 is the implementing regulation that operationalizes the Radon Certification Act. Under § 240, any individual or firm performing radon mitigation services for compensation in Pennsylvania must hold an active DEP certification issued by the Bureau of Radiation Protection. The certification is not transferable, is not inherited through business acquisition, and does not carry over if a certified contractor leaves one company to work for another. The certification attaches to the individual — the person doing the work must be certified, not simply the company name on the invoice.

Obtaining DEP certification is not a rubber stamp. Applicants must complete a DEP-approved training course that covers building science, sub-slab communication principles, fan selection and placement, pipe installation requirements, sealing techniques, electrical requirements, and post-mitigation testing. After the training course, applicants must pass a written examination administered by DEP. Certified contractors must carry liability insurance at minimum coverage levels specified by DEP and must renew their certification periodically, demonstrating continuing education in the field. The rigor of this process means that a currently certified contractor has, at minimum, demonstrated competency in the foundational knowledge required for correct system design and installation.

Pennsylvania recognizes two distinct certification categories that homeowners should understand. The Radon Mitigation Contractor (RMC) designation authorizes the holder to design and install radon mitigation systems. The Radon Testing Contractor (RTC) designation authorizes the holder to perform radon measurement and testing. A contractor may hold both designations — and many active professionals do — but holding one does not automatically confer the other. When you need someone to both test and mitigate, confirm that your contractor holds RMC certification before they install anything, and confirm that the tester performing your post-mitigation test holds RTC certification.

DEP accepts national credentials from the National Radon Proficiency Program (NRPP) and the National Radon Safety Board (NRSB) as recognized training pathways. A contractor who holds NRPP or NRSB certification has met nationally benchmarked standards for radon knowledge and proficiency — but holding a national credential does not substitute for PA DEP certification. A contractor can be fully NRPP-certified and still be in violation of Pennsylvania law if they have not obtained the separate PA DEP certification. In practice, most serious professionals in the Pennsylvania market hold both, and a contractor who holds national certification but has not bothered to obtain PA DEP certification is providing information about their operational standards.

The enforcement mechanism is real and has consequences. Per § 6.3 of Pennsylvania Radon Mitigation Standards document 294-2309-002, DEP has the authority to inspect systems installed by certified mitigators, review documentation, and investigate homeowner complaints. Violations may result in decertification — permanent loss of certification — suspension of certification pending remediation of the violation, or civil penalties under the Radon Certification Act. A homeowner who suspects a contractor has violated installation standards may file a complaint with the PA DEP Radon Division and request an inspection.

How to Verify DEP Certification in Two Minutes

Verification takes less time than reading this paragraph and should be the first thing you do before inviting any contractor into your home to provide an estimate. The PA DEP Radon Services Directory is publicly accessible at dep.pa.gov — no account, no fee, no registration required. The directory is searchable by contractor name or business name.

A successful search returns the contractor's full name, business name if applicable, certification type (RMC, RTC, or both), certification number, and — critically — the certification expiration date. All four of these fields matter. The certification type tells you what the contractor is licensed to do. The certification number is what you will look for on your system label after installation, confirming that the person who did the work was the person whose certification was verified. The expiration date tells you whether the certification was active at the time of your search. A certification that expired six months ago is not an active certification, regardless of what the contractor tells you about "renewal being in process."

If a search for a contractor's name returns no results, stop. Do not proceed with that contractor based on their assurance that there is a database error, that they are "in the system" under a different name, or that their certification just expired and is being renewed. All of these explanations may be true, and none of them authorize the contractor to perform mitigation work in Pennsylvania today. Call the PA DEP Radon Hotline at 800-237-2366 to resolve any discrepancy with DEP staff directly before proceeding.

In addition to the online database, certified contractors are issued a DEP photo identification badge that includes their certification number and expiration date. Asking to see this badge at the initial estimate visit is a reasonable request that any legitimate certified contractor will accommodate without objection. The badge provides a physical second-factor confirmation of the online database result. Some contractors, particularly sole proprietors, may not carry the badge to every visit — but they should be able to produce it or the DEP-issued certificate before work begins.

The contractor response test is a useful informal screening tool that costs nothing. Before the estimate visit, call the contractor and ask directly: "What is your PA DEP mitigation certification number?" A contractor who holds active certification knows their number — they use it on every invoice, every contract, every system label, and every DEP report. A contractor who responds with hesitation, confusion, a request to call you back, or a deflection to their company name or NRPP credentials rather than a specific DEP number is telling you something about how seriously they take the regulatory requirements of their profession. Any contractor who becomes defensive or dismissive when you explain that you intend to verify the number at dep.pa.gov before hiring is providing even clearer information. Defensive contractors do not become more professional after you sign the contract.

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

A radon mitigation system is not a product — it is a custom engineered installation whose design must respond to the specific conditions of the specific building where it will be installed. The assumption that every house with elevated radon can be fixed with a single suction pit in the middle of the basement floor and a standard-capacity fan is incorrect, and it is the assumption that produces systems that fail post-mitigation testing. A proper diagnostic is the process by which a certified contractor determines what system design is actually required.

The pre-installation diagnostic requirements are formalized in § 11.0 of Pennsylvania Radon Mitigation Standards document 294-2309-002. The first requirement is a thorough visual inspection of the building before any work begins — this is mandated by PA Code § 240.308(a) and must occur before a bid is submitted. The visual inspection covers foundation type and condition, floor plan layout including locations of load-bearing walls (which cannot be penetrated for pipe routing), floor drains and sump pits, utility penetrations through the foundation walls, HVAC system configuration and the location of natural draft combustion appliances such as gas furnaces and water heaters, and the general condition of the slab including visible cracks and expansion joints.

The sub-slab communication test is the diagnostic tool that determines how the soil or fill material beneath the slab distributes vacuum from a suction point. The procedure involves drilling one or more test holes through the slab at the proposed primary suction location and at two to three secondary locations distributed across the footprint of the building. A vacuum source — typically the mitigation fan being considered for installation, or a shop vacuum — is applied at the primary hole. A digital manometer or U-tube water gauge is used to measure the pressure differential at each secondary hole. If measurable negative pressure appears at all secondary locations, the sub-slab material communicates well and a single suction pit is likely sufficient to achieve adequate pressure field extension across the full footprint. If pressure differential fails to appear at secondary locations, the sub-slab communication is limited and additional suction pits will be required.

Sub-slab material characteristics determine communication capacity. Crushed stone and coarse gravel — common beneath Pennsylvania homes built before the 1980s — communicate extremely well because air moves freely through the void spaces between particles. Cinders and slag, used as sub-slab fill in older industrial-era Pennsylvania construction, also communicate well. Dense clay, compacted silty fill, and slab-on-grade over undisturbed native soil communicate poorly because there are few void pathways for air movement. Sand falls in between, with communication quality dependent on moisture content and compaction. A contractor who can describe the expected sub-slab conditions in your area — based on the construction era of your home and the regional geology — and who adjusts the diagnostic protocol accordingly is demonstrating the site-specific knowledge that distinguishes a qualified professional from someone following a fixed playbook.

Chemical smoke testing is used to identify the specific points where radon enters the building. Chemical smoke sticks or smoke puffers are placed at cracks in the slab floor, the wall-floor joint where the slab meets the foundation wall, around utility penetrations, at sump pit covers, and at exposed block wall surfaces. In a building under sub-slab vacuum — with the HVAC systems running and the building under normal operational pressures — smoke drawn toward these locations confirms active soil gas entry pathways. Sealing these entry points is a required component of an ASD installation under PA Code § 240.308(d) and directly affects system effectiveness.

The HVAC pressure relationship assessment evaluates whether the forced-air system in the building is creating negative pressure in the basement relative to the floors above. HVAC systems with significant return air imbalances — particularly systems where return air intakes are concentrated on upper floors while supply registers are distributed throughout — can depressurize basements by drawing air upward through the stack. This suction effect adds to the radon driving force from the sub-slab zone. A contractor who identifies this condition may recommend HVAC adjustments or additional sealing to reduce the baseline radon driving force before the mitigation system is installed.

The floor plan sketch that § 11.5 of 294-2309-002 recommends producing before system installation is the document that connects the diagnostic findings to the installation design. It should show: load-bearing wall locations (determining feasible pipe routing paths), drain locations and sump pit positions, HVAC supply and return register locations, natural draft appliance positions (relevant to combustion safety assessment after sub-slab depressurization is applied), and the proposed layout of suction pit locations, pipe routing, fan location, and termination point. A contractor who produces this sketch and walks you through it before installation begins is providing the transparency that a significant home improvement project warrants. A contractor who quotes a price over the phone based on square footage and drives up with materials already staged in their truck is providing a product installation service, not a professional engineering service.

The Pre-Hire Checklist: Questions to Ask Every Contractor

Screening radon mitigation contractors requires asking specific questions that separate qualified professionals from unqualified or undercertified operators. These questions should be asked before inviting anyone to conduct an estimate, and the answers should be evaluated against the correct responses described below.

What is your DEP certification number, and may I verify it at dep.pa.gov?

A qualified contractor provides their PA DEP Radon Mitigation Contractor (RMC) certification number without hesitation and explicitly encourages you to verify it at dep.pa.gov or by calling 800-237-2366. The number will be in the format that DEP uses for RMC certifications, and searching it in the Radon Services Directory will confirm active status, the contractor's name, and the certification expiration date. Any contractor who cannot immediately provide a specific certification number, who provides a national credential number (NRPP or NRSB) instead of a PA DEP number, or who becomes defensive when you explain that you intend to verify it independently, does not meet the minimum standard for consideration.

Will you conduct a pre-installation diagnostic before designing the system?

The correct answer identifies the specific diagnostic components by name: a sub-slab communication test using a vacuum source and pressure gauge to assess how well pressure field extension distributes from the proposed suction point, chemical smoke testing to identify active radon entry routes, a visual inspection of sump pits and utility penetrations, and a review of the foundation type and HVAC configuration. A contractor who describes the diagnostic process in these terms has the knowledge base the work requires. A contractor who responds that "every house gets one suction pit" or that they will "see what the space looks like when they get there" is describing an approach that is not compliant with § 11.0 of 294-2309-002.

What fan model do you plan to install, and why is it appropriate for my foundation type?

Fan selection must be matched to the sub-slab conditions discovered in the diagnostic — it cannot be predetermined before the diagnostic is conducted. That said, a qualified contractor can describe the fan selection logic in terms that reflect real knowledge. The RadonAway RP145 is the industry-standard fan for most Pennsylvania residential ASD applications — it is appropriate for moderate sub-slab resistance conditions, typical single-zone slab footprints, and homes where the communication test shows good pressure field extension. The RadonAway GP501 is appropriate for high-resistance sub-slab conditions: dense clay beneath the slab, large-footprint homes requiring extended pressure field coverage, isolated sub-slab zones separated by footings or interior walls that require multiple fan or multi-zone configurations. A contractor who can explain why one fan model is more appropriate than another for your specific conditions — and who waits for the diagnostic before making the final selection — is demonstrating the design competency the work requires.

Who will perform the post-mitigation test, and are they a separate DEP-certified RTC?

The ideal answer names a specific independent DEP-certified Radon Testing Contractor who will conduct the post-mitigation measurement, or describes the contractor's protocol for bringing in an independent tester. The same individual who installs the system should not be the individual who certifies its effectiveness — this is a conflict of interest that matters especially in real estate transactions, where the post-mitigation test result will be reviewed by a buyer's attorney and possibly by a lender. A contractor who installs their own post-mitigation test and signs off on their own work is not providing independent verification — they are providing self-reported performance data. In the context of Pennsylvania's regulatory framework, an independent test performed by a separate DEP-certified RTC is the standard that protects the homeowner's interest and the integrity of the result.

What does your warranty cover, and is it transferable if I sell the home?

Per § 18.1 of 294-2309-002, warranty terms must be disclosed in writing before work begins — this is not optional. A qualified contractor can describe their warranty clearly: what it covers (typically the system achieving a post-mitigation result below 4 pCi/L, fan replacement within the warranty period if the fan fails, and additional suction pits at no charge if the initial design fails post-mitigation testing), the warranty duration, what voids it (usually homeowner modifications to the system, structural changes that compromise sealed penetrations, or failure to follow the maintenance recommendations in the homeowner information package), and whether it is transferable to a subsequent owner of the property. A transferable warranty that documents the installation, the post-mitigation result, and the ongoing system performance commitment is a material asset in a future home sale — buyers in EPA Zone 1 counties who have been researching Pennsylvania radon will recognize its value. A contractor who cannot answer the warranty question in specific terms has not thought carefully about the post-installation relationship with their customers.

Will you provide the homeowner information package required by PA Code § 240.308(f)?

Every DEP-certified contractor knows about the homeowner information package requirement — it is a statutory obligation under PA Code § 240.308(f) and is reinforced in § 18.4 of 294-2309-002. Any contractor who responds with confusion or says they will leave paperwork on the counter has demonstrated that they are not operating to the standard their certification requires. The correct answer confirms that the contractor will produce a package including copies of the contract and warranty, a description of how the installed system works, manufacturer operation and maintenance instructions for the fan and all components, instructions for interpreting the monitoring gauge, a clear list of actions to take if the gauge indicates system failure, and the written recommendations to retest every two years and to obtain an electrical inspection of the system components. This package must be permanently attached to the system in a visible location — not left on the kitchen counter, not emailed to you, and not described verbally.

What the Contract Must Include

A verbal agreement with a radon mitigation contractor has no legal standing in Pennsylvania. The contract documentation requirement in § 18.1 of Pennsylvania Radon Mitigation Standards document 294-2309-002 is not a best-practice suggestion — it is a regulatory obligation that every DEP-certified contractor is required to satisfy before commencing work. Understanding what must be in the contract, and what to do if any element is missing, protects you from both poor workmanship and from having no recourse when something goes wrong.

The written contract provided before work begins must include the full name and DEP certification number of the certified individual who will perform the installation. Note that the requirement specifies the individual, not the company. If the company sends a different installer on the day of installation than the individual named in the contract, the installation may not comply with the certification requirement. Confirm before installation day that the named individual will be on-site, and verify their DEP certification number matches what is in the contract.

The planned scope of work must be described in enough detail to be verifiable after completion. This means the number and location of suction pit penetrations through the slab, the proposed pipe routing from suction pit to termination point, the fan model and its proposed installation location, the type and location of the performance monitoring gauge, and any sealing work to be performed at identified entry routes. A contract that says only "install ASD system, one suction pit, one fan" describes the minimum product but not the specific installation — and does not give you a basis for asserting that the work was not performed to the agreed scope if something is done differently.

Any chemicals or materials to be used during the installation that carry known hazards must be identified in the contract. This primarily covers the sealants and caulking compounds used to seal radon entry routes — urethane and polyurethane sealants classified under ASTM C920 are standard, and their safety data sheets include information about ventilation requirements and skin/eye contact precautions that are relevant to anyone in the building during or immediately after installation.

The statement of compliance with DEP standards and applicable local building codes is a formal representation by the contractor that the installation will meet 294-2309-002 requirements and that any permits required by the local municipality will be obtained. Some Pennsylvania municipalities require building permits for ASD system installations; the contractor is responsible for knowing whether local permit requirements apply and for obtaining them. A contractor who asks you to pull the permit yourself, or who says permits are not required without having verified local codes, is shifting a responsibility that belongs to the contractor.

The total installation cost must be stated clearly, and an estimate of annual operating costs must be included. The annual operating cost for a radon mitigation fan is primarily electricity — typical continuous fan operation costs $30 to $100 per year depending on fan model and local electricity rates in Pennsylvania. This figure should be in the contract so you understand the ongoing commitment before you agree to the installation.

Warranty terms must be fully stated in writing before you sign. The most important warranty element is the performance guarantee: does the contractor guarantee that the post-mitigation test will return below 4 pCi/L, and if not, what do they commit to doing — at no additional charge — to achieve that result? A contract without a performance guarantee transfers the risk of inadequate system design entirely to you. If the post-mitigation test returns above 4 pCi/L and the contract contains no performance commitment, you have no written basis for demanding that the contractor address the deficiency without additional payment. A contractor who will not commit in writing to achieving below 4 pCi/L is not confident in their design — and that uncertainty should be yours to evaluate before signing.

The Consumer Radon Mitigation Checklist: Verifying a Completed Installation

After the installation is complete and before you make final payment, walk through the following verification items drawn from the PA DEP Consumer Radon Mitigation Checklist for active sub-slab depressurization systems. Each item corresponds to a regulatory requirement under 294-2309-002 or PA Code § 240.308. If any item cannot be confirmed, contact the contractor and request correction before releasing final payment.

1. Has a post-mitigation radon test been performed, and do you have the written results? The test must have been performed no sooner than 24 hours after system activation and no later than 30 days after activation, using an NRPP/NRSB-listed device. You should receive the written test result directly — not a verbal report from the contractor about what the test showed.

2. Does the system discharge above the edge of the roofline? Per PA Code § 240.308(b), the vent pipe termination must be above the immediate roofline edge for pipes attached to the building side, must terminate at least 10 feet above grade, and must be at least 10 feet from any operable window, door, or other opening into conditioned spaces — or at least 2 feet above any such opening. Rain caps are prohibited. Walk outside and look at the termination point.

3. Is the fan located in an attic, garage (not beneath conditioned space), or on the exterior of the building? Per PA Code § 240.308(c), the fan may not be located in a basement, crawl space, conditioned space, or below grade. If the fan is in the basement, the installation does not comply with the standard.

4. Is there a performance monitoring gauge on the piping? Per § 16.1 of 294-2309-002, every active system must include a magnehelic gauge, U-tube manometer, airflow meter, or amperage meter that allows you to monitor whether the fan is operating correctly. The gauge must be visible from where you would normally occupy the space.

5. Does the system label include the installer's name, contact telephone number, and DEP certification number? Per PA Code § 240.308(e), the label must be permanently affixed to the system piping, legible from at least 3 feet, and must include all of these elements. A label that says only "Radon Reduction System" with no certification number is not compliant.

6. Does the system label include the installation date and the instruction to test every 2 years? Both of these elements are required on the label under § 240.308(e). The installation date establishes when the two-year retest clock begins. The retesting reminder is a statutory requirement, not an optional add-on.

7. Is the homeowner information package attached to the system? The package required by § 18.4 of 294-2309-002 must be physically attached to the mitigation system in a visible, accessible location. If the contractor has left materials on the counter, emailed them to you, or said they will send them later, the installation is not complete.

8. Are accessible cracks in the basement floor and wall-floor joint sealed? Per PA Code § 240.308(d), accessible radon entry routes — including the wall-floor joint where the slab meets the foundation wall, expansion joints, utility penetrations, and sump pit covers — must be sealed with urethane caulk or equivalent. Walk the perimeter of the basement and verify that visible cracks and the wall-floor joint show evidence of fresh sealant. Expanding foam in slab cracks is explicitly prohibited under § 15.5 of 294-2309-002.

If any item on this checklist is missing or non-compliant, contact the contractor in writing and request correction before releasing final payment. If the contractor does not respond or refuses to correct a deficiency, call the PA DEP Radon Hotline at 800-237-2366 to report the deficiency. DEP has the authority to inspect the installation and compel remediation.

Post-Mitigation Testing: The Step Most Homeowners Skip

The performance monitoring gauge installed on your mitigation system does one thing: it tells you whether the fan is running and generating airflow. It does not tell you whether the radon concentration in your home has actually been reduced. A manometer that reads within its expected operating range confirms that the fan is operational — it cannot confirm that the system is achieving adequate pressure field extension beneath the slab, that all radon entry routes have been sealed effectively, or that the post-mitigation radon level is below 4 pCi/L. The post-mitigation radon test is the only valid performance metric, and skipping it means you do not know whether the money you spent on the system accomplished anything.

The post-mitigation testing requirements are established in § 17.3 of 294-2309-002 and PA Code § 240.310(a)(11). The test must be a short-term measurement using an NRPP/NRSB-listed device — the same category of device used for pre-mitigation testing. It must begin no sooner than 24 hours after the system is activated (to allow initial radon concentrations to stabilize under the new pressure regime) and must be completed no later than 30 days after system activation. Closed-house conditions apply during the test period. The device must be placed in the same location as the pre-mitigation test — the lowest livable level of the home — so that the pre- and post-mitigation results are directly comparable.

Independence in post-mitigation testing is not a bureaucratic preference — it is a structural protection against a specific conflict of interest. A contractor who installs a system and then performs the post-mitigation test themselves is measuring the performance of their own work. If the result is below 4 pCi/L, you have no way to know whether that result reflects the true radon level or reflects a test placed in an advantageous location, conducted under conditions that favor a low reading, or simply reported inaccurately. In real estate transactions, this conflict is acute: buyers' attorneys and lenders who are reviewing post-mitigation test results in Zone 1 counties increasingly recognize that self-tested results lack the independence that gives the result evidentiary value. Request an independent post-mitigation test performed by a separately certified DEP RTC, and request that the test result be provided to you directly from the tester.

If the post-mitigation result is above 4 pCi/L, your written contract's performance guarantee is the mechanism for resolution. A contractor who has committed in writing to achieving below 4 pCi/L is obligated to adjust the system at no additional charge until the guarantee is met. The most common adjustments are: adding additional suction pits in areas of the footprint not being adequately reached by the initial pit, upgrading the fan to a higher-capacity model with greater static pressure capability (relevant when the initial fan was undersized for actual sub-slab conditions), and sealing additional radon entry routes that were missed in the initial installation. If the post-mitigation result is between 4 and 10 pCi/L — indicating partial but insufficient system performance — additional suction pits are typically the first adjustment. If the post-mitigation result is above 10 pCi/L despite the system running correctly, the system design likely requires a fundamental reassessment.

Once a successful post-mitigation result is confirmed, the EPA and PA DEP recommend retesting every two years. Radon fan performance degrades over time — motor bearings wear, impeller efficiency decreases, and static pressure output drops — and sub-slab conditions can change as soil settles, moisture levels shift, and building pressurization changes with HVAC modifications. A retest every two years catches performance degradation before it allows radon levels to return to action-level concentrations. The two-year retesting recommendation is on the required system label precisely because DEP wants occupants to understand that a successful post-mitigation test is not a permanent certification of indoor air quality — it is a point-in-time measurement that requires periodic reconfirmation.

Frequently Asked Questions

How do I verify a radon mitigation contractor is DEP-certified in Pennsylvania?

PA DEP maintains a publicly searchable Radon Services Directory at dep.pa.gov. Search by contractor name or business name to confirm active certification status, certification type (RMC for mitigation, RTC for testing), certification number, and expiration date. A certificate on a wall or logo on a website is not verification — only the live DEP database confirms current standing. You can also call DEP's Radon Hotline at 800-237-2366.

What should a pre-installation diagnostic include for a Pennsylvania radon mitigation system?

A proper pre-installation diagnostic under Pennsylvania Radon Mitigation Standards (294-2309-002) § 11.0 includes: a thorough visual inspection of the building before any work begins, a sub-slab communication test at multiple points using a vacuum source and pressure gauge or chemical smoke, identification of all radon entry routes including sump pits, floor drains, utility penetrations, and wall-floor joints, assessment of HVAC system pressure relationships, and a floor plan sketch documenting foundation type, load-bearing walls, drains, sump pits, and anticipated system layout. Any contractor who quotes a system without conducting or scheduling a diagnostic is providing a price estimate, not a system design.

What must a Pennsylvania radon mitigation contract include?

Per Pennsylvania Radon Mitigation Standards § 18.1, before work begins the contractor must provide in writing: their name and DEP certification number, the planned scope of work, any known hazards associated with chemicals used, a statement of compliance with DEP standards and applicable local codes, a description of any maintenance the homeowner must perform, the installation cost and estimated annual operating costs, and the terms of any warranty or guarantee. Review this documentation before signing — verbal guarantees are not enforceable.

What documentation must a Pennsylvania radon contractor provide after installation?

Per PA Code § 240.308(f)(1-6), upon completion the contractor must attach an information package to the mitigation system including: copies of contracts and warranties, a description of the installed system and operating principles, manufacturer operation and maintenance instructions including warning device interpretations, a list of actions to take if the warning device indicates failure, a recommendation to retest at least every 2 years, and a recommendation to have an electrical inspection performed on applicable components. This package must be permanently attached to the system in a visible location.

Can a radon mitigation contractor perform the post-mitigation test in Pennsylvania?

The post-mitigation test should be performed by a DEP-certified radon testing contractor (RTC) — ideally independent from the mitigation contractor — to avoid conflicts of interest. Pennsylvania Radon Mitigation Standards § 17.3 requires a short-term test no sooner than 24 hours and no later than 30 days after system activation using an NRPP/NRSB-listed device. In real estate transactions, an independent post-mitigation test is essential — buyers' attorneys and lenders will not accept a result produced by the same contractor who installed the system.

What are red flags when hiring a radon mitigation contractor in Pennsylvania?

Red flags include: inability to immediately provide a DEP certification number, quoting a system without asking about foundation type or sub-slab conditions, offering to perform both the installation and the post-mitigation test with the same individual, guaranteeing a specific post-mitigation result before conducting a diagnostic, pressure to sign a contract at the initial visit, and no written contract or warranty. Any contractor who becomes defensive when you ask to verify their DEP certification at dep.pa.gov is providing useful information about their professionalism.