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Verified Reviews for Radon Detection And Reduction pros in California, MD

*The Angi rating for Radon Detection And Reduction companies in California, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Radon Detection And Reduction needs.

*The HomeAdvisor rating for Radon Detection And Reduction companies in California, MD is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Radon Detection And Reduction needs.

Last update on February 23, 2026

Find Radon detection and reduction specialists in California

Avatar for Radon Abatement Services
Radon Abatement Services
4.9(
256
)

Serving California, MD and surrounding areas

Approved

In business since 1998

Free estimates

Warranties offered

"I used Radon Abetment Services LLC to install a radon system in my basement. John and his team were excellent and I highly recommend them to anybody with this need. John was able via video over phone identify where the system should go. His team was extremely professional and courteous. The installation took a day and the improvement in radon levels was remarkable. We would absolutely use them again."
Additional Photos
Recommended by97%of homeowners
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Avatar for Radon Abatement Services, LLC
Radon Abatement Services, LLC
4.6(
135
)

Serving California, MD and surrounding areas

Approved

In business since 1997

Free estimates

Customers say: Quick response

"I'm completely satisfied with the work that John's team did. They were extremely professional and knowledgeable. The workmanship is superb. Best of all, the system works as promised and reduced the radon concentration based on subsequent tests. I could not recommend them more highly."
Response time10 mins
Recommended by98%of homeowners
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Avatar for Mid Atlantic
Mid Atlantic
4.9(
18
)

Serving California, MD and surrounding areas

In business since 1985

Free estimates

Emergency services offered

"Chris was WONDERFUL! I just purchased a home and wanted to have a mold inspection done for peace of mind. Chris took time to explain the process and put my fears at ease with his vast knowledge. He reviewed the test results with me prior to closing which gave me the peace of mind I needed to confirm I was making a good purchase and great investment. I highly recommend Mid Atlantic Commercial Residential Real Estate Solutions. VERY PROFESSIONAL AND COURTEOUS!!"
Crawl Space
Crawl Space
Crawl Space
Crawl Space
Recommended by100%of homeowners
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Avatar for SWAT Environmental
SWAT Environmental
4.1(
91
)

Serving California, MD and surrounding areas

In business since 1988

Free estimates

Credit card accepted

"Mark did great work and made the radon abatement system blend well with the house. The office response time was slower than I would have liked, but the price and quality of work was worth the wait. All of the people I interfaced with were extremely helpful and nice. I would highly recommend this company."
Response time1 day
Recommended by90%of homeowners
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Avatar for Green Environmental LLC
Green Environmental LLC
5.0(
9
)

Serving California, MD and surrounding areas

In business since 2013

Free estimates

Emergency services offered

"Rodney is extremely professional, easy to schedule and highly knowledgeable about lead testing! Have used him many times and will continue moving forward. Highly recommend."
Recommended by100%of homeowners
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Avatar for Flood Crew LLC
Flood Crew LLC
4.6(
40
)

Serving California, MD and surrounding areas

In business since 2008

Free estimates

Emergency services offered

"I had a pipe burst in the basement of our rental property, Flood Crew was referred by our realtor. They arrived quickly after the pipe was fixed by our plumber, demoed, and dried out the areas, even handled packing out our furniture and placing carefully in a pod storage while the work was being done. They did mold testing and made sure everything was safe, the best part was that they dealt with the insurance and we didn’t have to do anything."
After carpets were cleaned.
Before and after of Medallion
After color sealed
Apartment carpet cleaning
Drying bathroom wood subfloor from kitchen using indirect control heat, controlled by thermostat we set in place

+57

Recommended by88%of homeowners
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Avatar for All States Air Duct Pro
All States Air Duct Pro
3.1(
236
)

Serving California, MD and surrounding areas

In business since 1995

Free estimates

Emergency services offered

"The technicians showed up on time, were thorough and professional, and did a fantastic job in cleaning up all of the air ducts in the household. In addition, they cleaned the heating/cooling unit itself, as well as the filters, to ensure that the entire system was covered.
"
Before & After Air Duct Cleaning
Recommended by49%of homeowners
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District Home Inspectors, LLC.
New to Angi

Serving California, MD and surrounding areas

In business since 2017

Free estimates

Credit card accepted

Welcome to District Home Inspectors. We are the premier professional Inspection company in Maryland. We offer the highest quality and most attentive customer service. We are known to pay exquisite attention to detail while making customer satisfaction our top priority. Whether your project involves minor evaluations or complete inspections, we are glad to be your number one choice. Please call us today to schedule your appointment!

Response time40 mins
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Radon Detection and Reduction questions, answered by experts

Ideally, no one will live in a house with elevated radon levels, as prolonged exposure increases the risk of serious health issues like lung cancer. However, homes with radon can be made safe through mitigation systems, such as active soil depressurization. Testing for radon regularly and addressing high levels helps ensure a safe living environment.

The cost for a radon mitigation system typically ranges from $800 to $1,500, with an average around $1,000. The final price depends on several factors, including the size of your home, the severity of the radon issue, and the type of system required. Your home's foundation type also significantly impacts the cost. For example, sealing and ventilating an unfinished basement might cost around $4,600, while encapsulating a crawl space without a foundation slab can range from $1,500 to $15,000.

Your radon fan needs to operate 24/7 to be effective. The only time the fan isn't operating is during its replacement. Radon levels in the home can increase within hours if the fan stops working or something obstructs the stack vent. Fortunately, radon systems require no downtime maintenance between fan changes.

Mitigation reduces radon levels, protecting your health and complying with safety standards.

Many radon fans carry a five-year manufacturer's warranty. That said, your radon fan should last between five and ten years. Regular inspections will ensure the fan is operating properly. Unusual or exceptional noise coming from the fan or indications on your manometer or system monitor can immediately tell you that something is amiss.

The California, MD homeowners’ guide to radon detection and reduction services

From average costs to expert advice, get all the answers you need to get your job done.

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