Call before you dig: how to get utility locates in Canada

STA 0+120The one-call centre in every province

Each of these is a free service. None of them charge an excavator to submit a request or a facility owner to respond to one¹.

Sask 1st Call's locate marks are valid for 30 calendar days from the ticket⁴, and Utility Safety Partners recommends building in more lead time between May and September, when request volume peaks².

STA 0+240Ontario runs on a statute, not just a member agreement

Ontario is the one province where the notification system is written directly into legislation, the Ontario Underground Infrastructure Notification System Act, 2012. That changes what an excavator can rely on:

• Standard request: a member receiving a locate request must mark its infrastructure, or confirm none is affected, within 5 business days of notification¹.
• Emergency request: a member must have someone on site, or provide a no-conflict statement, within 2 hours¹.
• Earliest submission: an excavator cannot submit a standard request more than 30 days before the dig is expected to start, and cannot start until locates are provided¹.
• No fee: members cannot charge for responding to a locate request¹.

STA 0+360Federally regulated pipelines

Interprovincial and international pipelines fall under the Canadian Energy Regulator, not the provincial one-call system alone. Anyone planning ground disturbance within the prescribed area, or work that crosses, sits on, or runs along or under a federally regulated pipeline, must submit a locate request through the one-call centre at least 3 working days before starting⁸. The prescribed area is a strip of land 30 m on each side of the pipeline centreline⁸. This is separate from, and in addition to, the provincial one-call request: a project that crosses a federally regulated line typically needs both the provincial ticket and direct contact with the pipeline operator listed for that segment. See trench safety and shoring for how provincial excavation rules layer additional proximity requirements on top of this, such as Alberta's 600 mm hand-digging zone around a marked line.

STA 0+480What the paint and flags mean

Canada uses a common colour code for utility locate marking, published by the Canadian Common Ground Alliance and mirrored in a 2022 colour code sheet from Utility Safety Partners in Alberta⁹:

White paint or flags always come first: the excavator marks the proposed work area white before submitting the request, so the facility owners know exactly where to check¹⁰. Paint fades and flags get knocked over on an active site, especially through wet weather or heavy equipment traffic, so it is worth photographing the marks when they go in and re-requesting a locate rather than relying on memory if work is delayed past the marks' stated validity period.

STA 0+600The request-to-dig sequence

The mechanics are consistent across every province, even where the notice period differs:

1. Mark the proposed excavation area white on the ground.
2. Submit a locate request online or by phone to the province's one-call centre, with the address, work description and start date.
3. The centre notifies its member facility owners, who each have their own crews mark their own lines within the notice period.
4. Wait for the notice period to run before starting, and confirm every affected owner has responded, not just some of them.
5. Expose lines by hand or hydrovac within the proximity zone set by the provincial excavation regulation before using mechanical equipment near a marked line. See hydrovac excavation and trench safety and shoring.
6. If marks are missing, unclear or expire before the dig starts, request a re-locate rather than guessing.

This sequence is also the first step in the earthworks sequence described in earthworks and excavation and in the site servicing process. Skipping a step is where most utility strikes come from: a hit on a live gas or electrical line is not just a schedule problem, it is an incident report, a repair bill charged back to the excavator, and in a serious case a stop-work order until the cause is reviewed. The notice periods above exist because the facility owner, not the excavator, decides how quickly its own crews can get a locator to the site.

STA 0+720What locates do not cover

A one-call centre notifies its own member facility owners. It does not mark lines a property owner installed privately, such as a service run to a detached garage, an irrigation line, or a private well line, and it does not replace the provincial excavation rules covered in trench safety and shoring. In Quebec and the Atlantic provinces, Info-Excavation's own guidance describes placing a request as strongly recommended rather than mandatory, though the provincial occupational health and safety rules separately require an employer to locate services before digging⁶. A locate ticket is also not a survey: it tells you a facility owner marked an approximate corridor, not the exact depth or whether other buried objects are present, so hand exposure near a mark is still the safest way to confirm what is actually there before a machine gets close.