The Best Radon Testing Services in Northglenn, CO
We graded 6 companies on seven things customers actually report: satisfaction, reliability, workmanship, value, momentum, track record and how owners handle complaints.
From 25,240 Google reviews of 71 top-rated radon testing services nationwide; 6 of them in Northglenn, CO. Updated November 3, 2026.
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Best radon testing services in Northglenn for installation
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Rocky Mountain Radon MitigationHow Job match is calculatedBuilt only from reviews Google tagged “Installation”:Stars on this job 55%5.00★Number of such jobs 25%42Overall Experts Score 20%99Job match= 99Stars are pulled toward the category average (4.93★) when a company has few tagged jobs, so 3 perfect reviews don’t beat 80 great ones. 4.3★ scores 0, 5.0★ scores full. Volume is compared with the busiest company for this job.99
Rapid Radon ReliefHow Job match is calculatedBuilt only from reviews Google tagged “Installation”:Stars on this job 55%5.00★Number of such jobs 25%6Overall Experts Score 20%100Job match= 85Stars are pulled toward the category average (4.93★) when a company has few tagged jobs, so 3 perfect reviews don’t beat 80 great ones. 4.3★ scores 0, 5.0★ scores full. Volume is compared with the busiest company for this job.85Job match = this company’s ★ on reviews Google tagged “Installation” (shrunk toward the category average when there are few), how many such jobs it has done, and its overall Experts Score.
What customers said about installation
Rocky Mountain Radon MitigationVery pleased with Rocky Mountain Radon Mitigation! Ian came out right away to give us an estimate, and Alec was great with handling the installation process! They have a lifetime warranty on their work. The radon fan comes with a 7 years warranty. Very pleased!
Rapid Radon ReliefRapid Radon Relief is a small family owned business but they're doing great job for installing Radon mitigation systems in the Denver area! Before the installation, Ryan explained the process in details to us then he's completed the entire job per code, we'd be happy to recommend them to our friends and neighbors.
Rocky Mountain Radon MitigationEXCELLENT..!! The team over at Rocky Mountain Radon Mitigation did a fantastic job. Ian is a great communicator— explanations of the process and typical job site photos helped us understand the project and the process. Scheduling with Ian was easy…and on installation day, our tech showed up on time. Our install…
Rapid Radon ReliefAs a realtor, we run into radon issues all the time and rapid radon has Exceeded my expectations great places, and usually can get me in the same week
Rocky Mountain Radon MitigationI interviewed four companies, and picked Rocky Mountain. Ian was super helpful and very clear on what they provided. Installation was great, Arthur knew exactly what he was doing. I hired a professional company to get the new radon report, and it was less than 2. Way below the EPA level. Success!
Rocky Mountain Radon MitigationWe had a full mitigation system installed Technician did an outstanding job. He was very clear on what work was required . And was very professional, knowledgeable and cleaned up all of his work areas. Highly recommended !!
Overall ratings
Experts Score 0–100Experts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. and a letter grade per factor (A = top 20% of radon testing services).
| # | Company | ScoreExperts Score (0–100)Absolute quality first: recency-weighted star average (≈54%), share of 1–2★ reviews (≈24%), customers’ price verdicts (≈14%), owner replies to critical reviews (≈7%); minus up to 10 points each for complaints flagged in Google review highlights and for a real slide in recent ratings. Hover a company’s score on its page for the full breakdown. | FactorsFactor grades, in orderSatisfaction (54%): Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.Reliability (24%): How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.Craft & service (0%): Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.Value (14%): Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.Momentum (0%): Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.Replies to reviews (7%): How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.One letter per factor score: A = 80+, B = 60–79, C = 40–59, D = 20–39, F = below 20. | ★Google star rating as shown on Google Maps. | Typical billMedian bill customers of this company reported in their reviews (needs 3+ priced reviews). |
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| 1 | Rapid Radon ReliefNorthglenn, CO | A 100How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%100+58.7Reliability 26%100+26.1Value 15%100+15.2Experts Score= 100Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAA– | 5.00 | — |
| 2 | Rocky Mountain Radon MitigationNorthglenn, CO | A 99How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%99+58.1Reliability 26%100+26.1Value 15%100+15.2Experts Score= 99Not enough data for replies to reviews; its weight is shared by the others.Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAA– | 4.99 | — |
| 3 |  Protect Environmental Radon MitigationNorthglenn, CO | A 90How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%89+48.5Reliability 24%86+20.8Value 14%100+14.1Replies to reviews 7%90+6.4Experts Score= 90Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAA | 4.81 | — |
| 4 |  Affordable Radon ServicesNorthglenn, CO | A 87How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%90+49.1Reliability 24%83+20.1Value 14%100+14.1Replies to reviews 7%54+3.8Craft & service penalty94−0.6Experts Score= 87Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AAAAAC | 4.90 | — |
| 5 |  SWAT Radon MitigationNorthglenn, CO | A 82How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 55%80+43.6Reliability 24%70+17Value 14%99+14Replies to reviews 7%100+7.1Experts Score= 82Grade A: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | AB–AAA | 4.79 | — |
| 6 | American Radon MitigationNorthglenn, CO | B 77How the Experts Score is calculatedEach factor is scored 0–100 on absolute terms (standing in the category can only raise it), then weighted; problems flagged in review highlights or a recent slide in ratings are subtracted:Satisfaction 59%82+48.1Reliability 26%66+17.2Value 15%100+15.2Craft & service penalty99−0.1Momentum penalty70−3Experts Score= 77Not enough data for replies to reviews; its weight is shared by the others.Grade B: A = 80+, B = 60–79, C = 40–59, D = 20–39. Needs 10+ reviews. | ABAAB– | 4.92 | — |
What jobs cost
What customers paid, from the price Google asks reviewers to report.
| Job | Low25th percentile: 1 in 4 customers paid less than this. | TypicalMedian of the bill customers reported in their Google review (Google asks reviewers for a price range; we use the middle of each range). | High75th percentile: 1 in 4 customers paid more than this. | FairOf customers who rated the price, the share who chose “Great price” or “Reasonable” rather than “Overpriced”. |
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Radon Testing Services in Northglenn, CO at a glance
How the 6 radon testing services we rated in Northglenn, CO compare, and what customers praise most.
Experts Score grades
A = score 80+, F = below 20.
- Grade A583%
- Grade B117%
- Grade C00%
- Grade D00%
- Grade F00%
Google ratings
Average stars per company.
- 4.90★ and up467%
- 4.80–4.89★117%
- 4.60–4.79★117%
- Below 4.60★00%
What customers praise
Share of Google review highlights.
- Quality6,69824%
- Professionalism7,31826%
- Responsiveness6,11322%
- Punctuality2,82810%
- Value5,19118%
Was the price fair?
All price verdicts left with reviews.
- Great price68240%
- Reasonable97057%
- Overpriced181%
- Not sure342%
Price verdicts by year
Share calling it great / reasonable / overpriced.
How we grade
Satisfaction (54%) — Recency-weighted star average (2-year half-life), shrunk toward the category mean by review volume; the company’s own lifetime average as the prior; absolute: 4.0★ = 0, 5★ = 100.
Reliability (24%) — How rarely jobs go badly: share of 1–2★ reviews — 60% the last 24 months (or the 20 newest if fewer), 40% all-time; 0% = 100, 15%+ = 0; the category percentile can only raise it.
Craft & service (penalty, up to −10) — Google review highlights: Quality, Professionalism, Responsiveness, Punctuality — how rarely reviewers flag them as a negative, per review since highlights began; 0% = 100, 5%+ = 0. Subtracted from the score (up to −10), never averaged in — clean highlights are the norm, not a bonus.
Value (14%) — Customers’ own price verdicts (Great / Reasonable vs Overpriced) and Value highlights; 65% absolute (all “reasonable” ≈ 80, “great” = 100), the category percentile can only raise it.
Momentum (penalty, up to −10) — Penalises only a real slide: last-12-month average below lifetime (−0.5★ = 0). Still 4.8★+ over the last year, or steady/improving = 100. Subtracted from the score (up to −10), never averaged in.
Replies to reviews (7%) — How often the owner publicly replies to reviews under 5★ (1–4★). Needs 3+ such reviews, otherwise not counted; 65% absolute (80%+ replied = 100), the category percentile can only raise it.