Niagara Region
Radon testing and mitigation in Welland, Ontario
Welland, the Rose City, sits where the Welland River meets the old canal, and it’s growing again with new homes on its north and east edges. Here’s what’s known about radon in Welland, and how to find out about your home.
- Region
- Niagara Region
- Population
- about 56,000
- Public health
- Niagara Region Public Health
- Local factors
- 4 reasons to test
Is radon a problem in Welland?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Welland home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
Radon in Welland
Welland, the Rose City, sits where the Welland River meets the old canal, and it’s growing again with new homes on its north and east edges. Its post-war neighbourhoods and older downtown homes make up most of the housing.
The ground under Welland
Welland sits on the Haldimand Clay Plain, dense glacial lake clay over limestone and dolostone. Clay slows soil gas, but cracks in dry spells, and the gravel under slabs and around weeping tile gives gas an easy path to foundations.
Welland’s homes
Older homes near downtown and along the canal have block or stone foundations. Post-war homes often have floor drains and sumps that connect directly to soil. New homes in the north end are larger and tighter, and Hunters Pointe and similar communities have many slab and basement bungalows.
What the data says
Ontario homes at or above Health Canada’s 200 Bq/m³ guideline in the 2024 Cross-Canada Survey, more than double the share found a decade earlier.Source: Cross-Canada Survey of Radon Exposure in the Residential Buildings of Urban and Rural Communities (2024)
Roughly how many homes per health region the first national survey (2009–2011) could test. Too few to clear any neighbourhood, which is why public maps can’t tell you about your house.Source: Health Canada — Cross-Canada Survey of Radon Concentrations in Homes, Final Report (2012)
Higher average radon exposure for rural residents than urban residents in a 2024 national study of 42,051 homes, mostly linked to drilled wells.Source: Goodarzi et al., Scientific Reports (2024) — rural communities and drilled-well annuli
Local results
Building a real radon picture for Welland
Public radon data for Southern Ontario towns is thin. The national surveys tested only a handful of homes per area. So we’re building our own: anonymized long-term results from homes we test, published by area once there are at least 30, so no single home can be identified and small samples can’t mislead.
Welland: collecting results. Already tested? Check your number and share it anonymously when you book.
Local factors
What can push radon up in Welland
Not a prediction for any single home, just the reasons a test is worth it here.
Clay plains
Dense clay slows soil gas, but it cracks in dry spells. Gas then follows the easiest route: the gravel backfill, weeping tile and utility trenches that lead straight to a basement.
Century homes
Fieldstone, rubble and early concrete foundations, earth-floor cellars and open sumps give radon many ways in. Older doesn’t mean safer: these homes still need a test.
New, airtight construction
Canadian research shows newer homes have tended to test higher than older ones. Bigger, taller and tighter homes create a stronger stack effect that draws soil gas in through the slab.
Lived-in basements
Radon is usually highest on the lowest floor. Basement bedrooms, home offices and rental suites mean people spend hours a day where exposure is greatest.
Where we work
Welland neighbourhoods and nearby communities
- Downtown Welland
- Dain City
- Hunters Pointe
- North End
- Niagara College area
- Cooks Mills
Nearby: Radon in Fonthill · Radon in Port Colborne · Radon in Thorold · Radon in Niagara Falls
How it works
From test to fix
- Book
Tell us about your Welland home. We reply within one business day.
- Test for 91+ days
A certified technician places long-term detectors on your lowest lived-in floor. You get an early reading at 2 weeks.
- Get your result
Lab-verified average, explained against Health Canada’s guideline.
- Fix it if it’s high
A sub-slab system designed for your foundation, at a fixed price, with results guaranteed.
Questions
Radon in Welland: FAQ
Is radon a problem in Welland?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Welland home. No published local data rules any neighbourhood in or out. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, cracking clay soils, century-home foundations and new airtight construction are reasons to test. A 91-day test is the only way to know your home’s level.
My Welland home is on clay. Do I still need to test?
Yes. Clay slows soil gas through undisturbed ground, but the gravel and backfill around your foundation is a different story. Clay-plain homes can and do test high.
Can a sump pit let radon in?
An open sump is one of the most common radon entry points. Sealing it with an airtight, serviceable lid is part of nearly every mitigation we do, and in some homes the sump itself becomes the suction point.
Do you offer radon testing and mitigation in Welland?
Yes. We test and mitigate homes throughout Welland, including Downtown Welland, Dain City, Hunters Pointe, North End, Niagara College area and nearby. Call (226) 271-4667 or book online.
Radon is fixable. First, know your number.
Serving Welland, Fonthill, Port Colborne, Thorold and Niagara Falls.