Ontario One Call: the locate you need before digging in Ottawa.
Before anyone digs in Ottawa, a locate request goes to Ontario One Call. It is free and required by law, and it covers a homeowner planting a tree as much as a contractor with a machine. Ontario's Underground Infrastructure Notification System Act, 2012 calls anyone who digs, bores, trenches, grades or moves earth an excavator, and it bars that person from starting until every notified utility has marked its lines or confirmed in writing that nothing of theirs is in the way. On a standard request each utility has five business days. Two things catch people out. The paint shows where a line runs, never how deep it is. And the free service does not mark private lines, like a gas line from the meter to a barbecue or a cable out to a garage.
Planning a dig this season?
Tell us what is going in the ground and where. We will say what the locate covers, what it will not, and how the wait fits your start date.
(613) 852-4059A shovel counts. So does a fence post.
A common belief about locates is that hand digging does not need one. The Act does not agree. Its definition of an excavator is any individual, partnership, corporation or public agency that digs, bores, trenches, grades, excavates, moves or breaks earth, rock or the materials in the ground, or intends to, and nothing in it mentions a machine.
Enbridge Gas lists a fence, a garden, a tree, a deck and a pool among the projects that need one, and says even small projects do.
Who files is the person holding the shovel. Ontario One Call says the person physically completing the excavation is responsible for obtaining locates, regardless of whose property it is. Hire a fence company or a landscaper and the request is theirs, though Enbridge tells homeowners never to assume it was done and to ask for proof.
Skipping it is an offence under section 18, with a fine of up to $10,000, and Enbridge adds that whoever damages a line through unsafe digging pays the full cost of the repair.
What happens after you submit the request.
Requests go in online, through the Ontario One Call web portal. The Corporation's own FAQ says all locate requests need to be placed online, and that its support line at 1-800-400-2255 can answer questions but cannot place a request for you. You will need your contact details, the dig address with the two nearest intersecting streets, the type of work, and ideally whether you are digging by hand or by machine.
Ontario One Call does not send anyone to your yard. It passes the dig details to every member whose infrastructure might be affected, and under section 5 of the Act the members include every municipality in Ontario, every gas distributor, every electricity distribution operator and anyone whose buried plant crosses a public right of way. In Ottawa that means the City's own water and sewer lines can be on the same request as gas, power and telecom.
Each member either marks its lines and gives you a written locate sheet, a completed locate, or states in writing that none of its plant is affected, a clear. Responses show up on the portal, and the dig waits for every one of them.
The clock is set by law. For a standard request, section 6(3) gives each member five business days from the day it is notified. Ontario One Call applies that to a single civic address and allows 10 business days for an advanced request covering more than one property. The law also stops you filing early: a standard request cannot go in more than 30 days before the dig is expected to start. Ontario One Call says the deadline is not a guarantee; chase a late member directly first. The two-hour emergency request exists, but the Act reserves it for a lost utility service that creates an imminent hazard, so a deck that has to start on Monday does not qualify.
Reading the marks, colour by colour.
Locates arrive as paint, flags or stakes, and the colour tells you whose line it is. Red is electric. Yellow is gas, oil or steam. Orange is communications. Green is sewer and storm. Blue is water. Purple is irrigation or slurry. Pink is a temporary survey marking. White is the one you can put down yourself: it outlines the proposed excavation, and Ontario One Call encourages excavators to pre-mark the dig area that way so the locator knows exactly where you mean.
The paint and the paperwork have to agree. Section 10 of the Act does not let a dig start unless the excavator has checked that the markings on the ground do not conflict with the written locate information. If they disagree, stop and call the member before a machine goes near it.
Marks do not last forever. A locate is valid for 60 days under section 8, or longer if the member says so on the sheet, and it is treated as expired the moment the markings are no longer visible. Paint mowed off a lawn or a flag pulled up can end a locate early. Enbridge is explicit that moved flags or removed paint make a locate invalid.
How deep are gas lines buried? The paint will not say.
This is the question people search after the flags go in, and there is no number to give. Enbridge Gas states that locates show the direction and approximate location of a natural gas line but do not show its depth, and that a natural gas line could lie just a few inches below the surface. On its homeowner page the warning is shorter: buried lines may not be as deep as you expect.
Nor is the line exactly under the paint. Enbridge treats one metre either side of a mark as the tolerance zone, where you expose the line with a shovel or a hydrovac, in shallow scoops, before any machine digs.
The instructions on each member's locate sheet are what to dig by. Ontario One Call's example of those instructions reads simply: dig by hand within 1 metre of the markings.
The lines Ontario One Call does not mark.
Everything above covers utility-owned plant. Anything installed privately on your side of the meter is yours, and the free service will not find it. Ontario One Call's own list of examples is a gas line from the house to a barbecue or pool heater, lights or signs on the property, electrical lines out to a shed or a detached garage, sewer and septic tanks, systems and piping, and telecom or electrical lines feeding security cameras. It adds wells to the same category.
Those need a private locator, hired separately, and Enbridge notes there is a charge for that service. You still submit the Ontario One Call request first. The Corporation is clear that homeowners, or contractors on their behalf, must file whether the dig is on public or private property, and the confirmation will prompt you to arrange private locates for the rest.
If a line gets hit: stop, clear, call.
For gas, Enbridge's instructions are the ones to follow. Stop work and shut off all equipment to avoid ignition. Do not try to control the escaping gas. Move everyone a safe distance away, call 911, and call the Enbridge Gas emergency line at 1-866-763-5427.
For any other line, Ontario One Call says to call the owner of that infrastructure directly, and to leave the excavation open until it has been inspected. A scrape that looks cosmetic matters too: the Corporation warns that even a nick in a sheath or coating can cause corrosion that becomes a problem later, and backfilling over it hides the damage from the owner who has to assess it.
How this fits into an excavation job.
On a job site the duty also sits in workplace law: section 228 of Ontario Regulation 213/91 requires an employer to have services in and near a dig located and marked before it begins.
That is why the locate request is the first line of our excavation work. We submit it through Ontario One Call before we break ground, build the five business days into the schedule, and plan the dig around the marks and the sheets that come back. If your project has private lines on it, tell us when you book, because those need their own locator and their own days.
A locate request, step by step, and what sets each rule.
Rules from the Act, O. Reg. 213/91, Ontario One Call and Enbridge Gas, read on 2026-09-12, and linked at the foot of this page.
| Step | What happens | Where the rule comes from |
|---|---|---|
| Decide who files | The person physically doing the digging submits the request, homeowner or contractor. | Ontario One Call. The Act calls anyone who digs, bores, trenches or grades an excavator. |
| Submit the request | Online through the Ontario One Call portal. Free, and not more than 30 days before the dig. | Act ss. 5.1(4) and 12(1). The support line cannot place a request. |
| Wait for every member | Each notified utility marks its lines or states in writing that the dig is clear. | Act ss. 6(1) and 10(1). Five business days on a standard request, s. 6(3). |
| Check the marks | Paint or flags must match the written locate sheet before digging starts. | Act s. 10(1). Colours per Ontario One Call: red electric, yellow gas, blue water, green sewer. |
| Dig near a mark | Expose the line by hand or hydrovac within one metre either side of the mark. | Enbridge Gas tolerance zone. Marks show position, never depth. |
| Private lines | Hire a private locator for lines to a barbecue, pool heater, shed, garage or septic system. | Ontario One Call. Enbridge notes a private locate carries a charge. |
| Keep the locate valid | Finish within 60 days, or longer if the sheet says so. Faded or moved marks end it. | Act ss. 8(1) and 8(3). |
Yes, for the utility locate. The Ontario Underground Infrastructure Notification System Act, 2012 says the Corporation shall not charge an excavator a fee for submitting a locate request, and that a member utility shall not charge a fee for marking its lines or clearing the request. Private lines are different: a gas line to a barbecue or a cable to a garage needs a private locator, and Enbridge Gas notes there is a charge for that.
On a standard request each notified utility has five business days from the day it is notified, under section 6(3) of the Act. Ontario One Call applies that to a single civic address and allows 10 business days for an advanced request covering more than one property. You cannot submit a standard request more than 30 days before the dig, and the Corporation says the deadline is not a guarantee, so build in a margin.
Yes. The Act defines an excavator as anyone who digs, bores, trenches, grades, excavates, moves or breaks earth, with no exception for hand tools. Enbridge Gas lists planting a tree, a garden and a fence among the projects that need a locate. The person physically doing the digging is responsible for the request.
There is no depth you can rely on. Enbridge Gas states that locates show the direction and approximate location of a gas line but not its depth, and that a natural gas line could lie just a few inches below the surface. It treats one metre either side of a mark as the tolerance zone, where the line is exposed with a shovel or hydrovac before any machine digs.
No. Those are private lines. Ontario One Call lists gas lines from the house to a barbecue or pool heater, electrical lines to a shed or detached garage, sewer and septic piping, lighting and security camera cables as the homeowner's responsibility. You still submit the free request first, then hire a private locator for the rest.
Sixty days under section 8 of the Act, or longer if the utility says so on its locate sheet. The locate is treated as expired as soon as the markings are no longer visible, and Enbridge Gas says moved flags or removed paint make it invalid. If the job runs past that, a new request goes in before digging continues.
Sources
- Government of Ontario, Ontario Underground Infrastructure Notification System Act, 2012 read 2026-09-12
- Government of Ontario, O. Reg. 213/91, Construction Projects read 2026-09-12
- Ontario One Call, Homeowners: public utility locates, private locates and FAQ read 2026-09-12
- Ontario One Call, Glossary read 2026-09-12
- Enbridge Gas, Safe Digging for Homeowners read 2026-09-12
- Enbridge Gas, Digging Safety for Contractors read 2026-09-12
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