Who is responsible for digging safely under Ontario law?

Under the Ontario Underground Infrastructure Notification System Act, 2012, the responsibility falls on the excavator, and that term covers anyone who digs, bores, trenches, grades, excavates, moves or breaks earth, or intends to. That includes a homeowner digging their own footing holes, not just a contractor.

Section 10(1) of the Act is direct: an excavator shall not start to dig unless they have submitted a locate request and each affected member has responded. Members have five business days to respond under section 6(3), so the locate request has to go in before work begins, not the morning of. Section 5.1(4) confirms there is no fee charged to an excavator for submitting a locate request.

Ontario One Call puts it plainly on its homeowner page: if you are building a deck or doing any project that requires digging, contact Ontario One Call at least five business days before to request a public utility locate. Their words are "it's free, it's easy, it's the law." If you hire a contractor, the obligation does not disappear on your end: Ontario One Call says to make sure the contractor contacted Ontario One Call before starting.

One thing the locate does not cover automatically is private lines on your property. Those are your responsibility to have marked separately. Lines worth thinking about before any footing work include:

• a gas line running from the house to a barbecue or pool heater
• electrical lines to a shed or detached garage
• sewer and septic piping
• telecom or electrical lines feeding security cameras or exterior lights

If a contractor is doing the digging, the legal duty sits with them as the excavator, but Ontario One Call still recommends that homeowners confirm the locate was requested before a shovel goes in the ground. There is no cost to you either way, and the five-business-day window means it needs to be part of the project schedule from the start, not an afterthought once the builder shows up.

When you get a deck quote, ask the builder to show you each line item separately: railings, stairs, removal of an existing deck, permit drawings, and the foundation, so you can see exactly what the price does and does not include.