Waterloo Region
Radon testing and mitigation in Waterloo, Ontario
Waterloo is home to two universities, a large technology sector and a large student rental market. Here’s what’s known about radon in Waterloo, and how to find out about your home.
- Region
- Waterloo Region
- Population
- about 121,000
- Public health
- Region of Waterloo Public Health
- Local factors
- 5 reasons to test
Is radon a problem in Waterloo?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Waterloo home. Cancer Care Ontario’s table of Health Canada survey data put the Region of Waterloo at 4.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and lived-in basements are reasons to test. A 91-day test is the only way to know your home’s level.
Radon in Waterloo
Waterloo is home to two universities, a large technology sector and a large student rental market. In the Health Canada survey data that Cancer Care Ontario tabulated by public health unit, 4.0% of the homes tested in the Region of Waterloo were at or above Health Canada’s 200 Bq/m³ guideline. That is a regional figure, and with so many people living in basements and lower levels here, it is worth checking your own.
The ground under Waterloo
The city sits on the Waterloo Moraine, a ridge of sand, gravel and till that is an important source of the region’s drinking water. Sand and gravel let soil gas move freely, and the till includes ground-up rock from the Canadian Shield. Together they mean radon can form close to the footings and travel to them.
Waterloo’s homes
Student housing around Uptown and the two campuses is a mix of converted houses and purpose-built rentals, with many basement bedrooms. Beechwood, Westmount and Lakeshore are established neighbourhoods of 1960s to 1980s homes, and Laurelwood, Vista Hills and Eastbridge hold newer, larger homes. In student rentals, who arranges the test is often unclear, so landlords and tenants should agree before the first winter.
What the data says
Of homes tested in the Region of Waterloo were at or above 200 Bq/m³ in the Health Canada survey data tabulated by Cancer Care Ontario (2009 to 2013).Source: Cancer Care Ontario — Risk of Residential Radon Exposure Varies Geographically (results by public health unit, Health Canada survey data 2009–2013)
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)
Local results
Building a real radon picture for Waterloo
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.
Waterloo: collecting results. Already tested? Check your number and share it anonymously when you book.
Local factors
What can push radon up in Waterloo
Not a prediction for any single home, just the reasons a test is worth it here.
Sandy or gravelly soils
Sand and gravel let soil gas move freely and over longer distances. More of the radon formed in the ground can reach the air around your foundation instead of decaying in place.
Glacial soils with Shield debris
The till and gravel left by glaciers here includes ground-up rock carried south from the Canadian Shield. Uranium travels with it, so radon can form close to your footings even where the bedrock itself is low in uranium.
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.
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.
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.
Where we work
Waterloo neighbourhoods and nearby communities
- Uptown Waterloo
- University District
- Beechwood
- Westmount
- Lakeshore
- Laurelwood
- Vista Hills
- Eastbridge
- Colonial Acres
- Conservation Park
- Waterloo West
- Northdale
Nearby: Radon in Kitchener · Radon in Cambridge
How it works
From test to fix
- Book
Tell us about your Waterloo 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 Waterloo: FAQ
Is radon a problem in Waterloo?
Radon can exceed Health Canada’s 200 Bq/m³ guideline in any Waterloo home. Cancer Care Ontario’s table of Health Canada survey data put the Region of Waterloo at 4.0% of homes at or above the guideline. Across Ontario, about 1 in 8 homes tested at or above the guideline in the 2024 national survey. Locally, sandy or gravelly soils, Shield-derived glacial soils and lived-in basements are reasons to test. A 91-day test is the only way to know your home’s level.
Who should test a rented basement in Waterloo?
The owner usually arranges it, but anyone can test. Place the detector in the suite’s main living or sleeping area, since Health Canada’s guideline applies wherever someone spends more than four hours a day. A long-term test needs at least three months, so start early in the lease.
My Waterloo home is only a few years old. Do I still need to test?
Yes. Canadian research has found that newer homes have tended to test higher than older ones, because they are bigger, taller and tighter. A rough-in pipe from the 2024 Ontario Building Code does nothing on its own until a test shows it needs a fan.
Do you offer radon testing and mitigation in Waterloo?
Yes. We test and mitigate homes throughout Waterloo, including Uptown Waterloo, University District, Beechwood, Westmount, Lakeshore and nearby. Call (226) 271-4667 or book online.
Radon is fixable. First, know your number.
Serving Waterloo, Kitchener and Cambridge.