Radon in Grimsby
Grimsby sits on the narrow strip between Lake Ontario and the Escarpment, and has been one of Niagara’s fastest-growing towns.
Grimsby radon guide
Radon in Niagara Region
Radon testing and mitigation in Niagara Region
Twelve municipalities between two Great Lakes: escarpment benches, fruit-belt lake plain, the Fonthill hill and limestone along Lake Erie.
Radon in Niagara Region
Niagara packs a lot of geology into a small region, and a lot of housing types too: heritage homes in Niagara-on-the-Lake, post-war neighbourhoods in St. Catharines and Welland, cottages at Crystal Beach and Grimsby Beach, and new townhomes and subdivisions everywhere from Grimsby to Fort Erie. We cover all twelve municipalities.
What’s under the ground
North of the Escarpment, the fruit belt and St. Catharines sit on the Iroquois Plain: lake sands, silts and clays over red shale. On top, Thorold and Niagara Falls sit on dolostone cap rock. The Fonthill Kame in Pelham is a huge hill of glacial sand and gravel. To the south, Welland and Port Colborne sit on the Haldimand Clay Plain, and near Fort Erie and Port Colborne limestone comes close to the surface.
The homes
Niagara’s mix of century homes, lakeside cottages and brand-new construction means entry points vary widely: stone foundations and crawlspaces in the old towns, sumps and floor drains in post-war basements, and tight, tall new homes with a strong stack effect. Wherever you are in the region, a 91-day winter test is the place to start.
Public health: Niagara Region Public Health.
What the data says
1 in 8
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)
~100
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)
+30%
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 factors
Why Niagara homes should test
Shallow or fractured bedrock
Where rock sits close to the surface, as on the Niagara Escarpment or the limestone plains near Lake Erie, joints and fractures can act as pipelines that carry soil gas toward foundations.
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.
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.
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.
Cottages and crawlspaces
Lakeshore cottages converted to year-round homes often sit on crawlspaces, piers or patched slabs. Once winterized and heated, they can start pulling in soil gas they never did as summer places.
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.
Communities
Where we work in Niagara Region
Radon in Lincoln (Beamsville, Vineland & Jordan)
The Town of Lincoln is the heart of Niagara wine country: Beamsville, Vineland, Jordan and Campden, with vineyards and orchards between.
Beamsville radon guide
Radon in St. Catharines
St. Catharines is Niagara’s largest city, with neighbourhoods from heritage Port Dalhousie to post-war Grantham and the hillside homes around Brock University.
St. Catharines radon guide
Radon in Niagara-on-the-Lake
Niagara-on-the-Lake holds some of Ontario’s oldest homes.
NOTL radon guide
Radon in Thorold
Thorold sits on top of the Escarpment along the Welland Canal, with a historic downtown, new subdivisions like Rolling Meadows, and a large student rental market tied to Brock University next door.
Thorold radon guide
Radon in Niagara Falls
Beyond the tourist core, Niagara Falls is a city of established neighbourhoods (Stamford, Drummondville, Chippawa) and a lot of new construction in the south and west ends.
Niagara Falls radon guide
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.
Welland radon guide
Radon in Pelham (Fonthill & Fenwick)
Pelham is Fonthill, Fenwick, Ridgeville and the countryside around them, a desirable, growing town of larger family homes and estate lots, many on rural properties.
Fonthill radon guide
Radon in Fort Erie
Fort Erie stretches from the Peace Bridge to Crystal Beach, taking in Ridgeway, Stevensville and a long Lake Erie shoreline.
Fort Erie radon guide
Radon in Port Colborne
Port Colborne is a Lake Erie canal town with a working harbour, older neighbourhoods, lakeshore cottages toward Sherkston and growing new subdivisions.
Port Colborne radon guide
Questions
Radon in Niagara Region: common questions
Is radon a concern in Niagara?
Yes. Like everywhere in Ontario, homes in Niagara can exceed Health Canada’s guideline, and there’s no published local data that rules out any municipality. The region’s mix of fractured bedrock, gravel and clay soils, and old and new homes, means results vary a lot from house to house.
Do you cover all of the Niagara Region?
Yes. We test and mitigate in all twelve municipalities: Grimsby, Lincoln, West Lincoln, St. Catharines, Niagara-on-the-Lake, Thorold, Niagara Falls, Pelham, Welland, Wainfleet, Port Colborne and Fort Erie.
Book a radon test in Niagara Region
C-NRPP certified testing and mitigation across Grimsby, Beamsville, St. Catharines, NOTL, Thorold, Niagara Falls, Welland, Fonthill, Fort Erie, Port Colborne.