Do I need to call before I dig in Ontario?

Yes. Under Ontario's Underground Infrastructure Notification System Act, anyone digging in Ontario, including homeowners on private property, must contact Ontario One Call for utility locates before digging. The service is free; request it online or at 1-800-400-2255 at least five business days before work starts.

What happens to the soil dug out during excavation in Ontario?

Excess soil is regulated under Ontario Regulation 406/19. Soil should be reused on site where possible or taken to an appropriate reuse site or facility. Small projects have reduced requirements, but the property owner is still responsible for making sure soil isn't contaminated.

Do I need a permit for excavation in London, Ontario?

Many projects that involve excavation, such as additions, garages, foundations and inground pools, require building or other permits. Work near watercourses or regulated areas may also need a conservation authority permit. Check with the City of London and your conservation authority before digging.

How deep do footings need to be in Southwestern Ontario?

Footings must sit below the frost line. In the London area, designs commonly place footings around 4 feet below grade, but your engineer, designer and building permit set the actual depth.

What should I look for in an excavation contractor?

Look for WSIB coverage, liability insurance, experience with your type of project, a clear plan for locates, soil management and grading, and a written quote that spells out what's included.

Excavation Checklist for Ontario Homeowners and Builders: Locates, Excess Soil and Site Prep

Kayden Stone

Oct 4

4 min read

Every great build starts with a hole in the ground done right. Whether you're adding a garage, digging for an addition, prepping a lot for a new home, trenching for services or clearing space for a backyard project, excavation is where schedules and budgets are won or lost. This checklist covers what homeowners and builders in London and Southwestern Ontario need to sort out before the machine shows up.

1. Request utility locates (it's the law)

Before any digging in Ontario, you must contact Ontario One Call. Under the Ontario Underground Infrastructure Notification System Act, passed in 2012, anyone digging in the province has to request locates first, even homeowners on private property. The service is free.

Request online at ontarioonecall.ca or call 1-800-400-2255.
Submit the request at least five business days before your dig date.
Homeowners can request by phone; contractors are expected to use the online portal.

Why it matters: underground lines in Ontario are damaged more than 3,900 times a year, about 17 incidents every workday, and Ontario One Call's 2025 research found 57 percent of homeowners didn't request a locate before their last digging project, according to the City of Kingston. Note that public locates don't cover private lines, such as wiring to a detached garage or a pool heater, so plan for those separately.

2. Confirm permits and approvals

Building permits. Additions, garages, foundations and many accessory structures need a building permit from your municipality. In London, start with the City's building permits page.
Pools. Inground pools in London require a pool fence permit that includes a grading and drainage plan.
Conservation authority permits. Work near rivers, creeks, wetlands, valleys or the Lake Huron shoreline may need a permit from the local conservation authority. Ontario Regulation 41/24 governs development in these hazard areas.
City property. Work in the road allowance or boulevard may need City approval.

3. Plan where the soil is going

Excavation creates a lot of material, and in Ontario that material is regulated. Ontario Regulation 406/19 governs on-site and excess soil management.

Reuse soil on site for backfill and grading wherever possible. It's cheaper and simpler.
The province's 2024 amendments exempt very small projects, those generating or reusing 5 cubic metres or less, from hauling records, according to Landscape Ontario.
Larger volumes need records showing where soil came from and where it went, and very large projects have registry and planning requirements.
As of January 2025, excess soil that meets Ontario's quality standards is restricted from being landfilled, which pushes projects toward reuse.

A good excavation contractor will have a soil plan before digging starts.

Excavation crew in safety vests reviewing a residential site plan beside heavy equipment

4. Check soil and water conditions

Clay is common around London and Middlesex. It holds its shape for digging but drains poorly and can soften when wet.
Groundwater in low areas or near creeks may mean pumping and slower progress.
Frost depth matters for footings. In the London area, designs commonly put footings around 4 feet below grade; your engineer and permit drawings set the exact depth.
Trench safety. Deep excavations must follow Ontario's construction safety regulations for sloping or shoring. Never let anyone work in an unsupported deep trench.

5. Plan access and protect the property

Measure gates and side yards. Compact excavators and skid steers fit where full-size machines can't.
Identify trees, septic systems, wells, irrigation and buried lines to protect.
Plan a route for trucks and a spot to stockpile topsoil separately from subsoil.
Consider ground protection mats on lawns and driveways.

6. Plan the finish before you start

The best time to think about final grade, drainage and landscaping is before the first scoop.

Where will water go once the project is done? See our guide to lot grading in London.
Do you need French drains, catch basins or sump discharge lines? See yard drainage solutions.
Will the disturbed area be sod, interlock or gardens? Stockpile and protect good topsoil.

7. Choose the right excavation contractor

WSIB coverage and liability insurance
Experience with your type of project and soil
A written scope covering locates, digging, soil handling, backfill, grading and cleanup
Clear communication about schedule and weather delays

Common excavation projects we handle

Additions, garages and new build site prep
Footing and foundation digs
Trenching for drainage and services
Grading and land clearing
Inground pool removal and backfill
Commercial site preparation

Frequently asked questions

Do I need to call before I dig even for small jobs?

Yes. Planting trees, installing fence posts and building decks all require locates.

Can excavated soil be reused on my property?

Often, yes. Reusing soil for backfill and grading is encouraged and usually the most cost-effective option.

How long does residential excavation take?

Small digs can take a day; larger additions or site prep can take several days to weeks depending on soil, water and access.

What areas does SPM serve?

London, St. Thomas, Strathroy, Komoka, Ilderton, Dorchester, Kitchener, Waterloo, Guelph and the Lake Huron shoreline.

Book your excavation project

SPM Landscape & Excavation has been digging, grading and preparing sites across Southwestern Ontario since 2006. Call or text (519) 474-0008 for a free quote.

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