Before You Dig in an Ontario Backyard: Who Each Party Is in the Locate System, and the One Set of Lines No One Has to Mark

After a locate, colored paint and small flags appear on the lawn. They are a record of a transaction between named parties — you the excavator, Ontario One Call in the middle, and the members who own the lines. Read the cast, and the marks start to mean something.

I’m Arthur Zhao, a Toronto real estate broker. After a utility locate is done on a property, a scatter of colored paint lines and small flags turns up across the lawn — red, orange, blue, yellow — and the natural way to read them is as one flat message: here is where not to dig. They are actually a record of a specific exchange between named parties. Each mark was placed by, or for, a particular owner of a particular buried line, in answer to a request the law required someone to make. Read that way, the paint tells you two things at once — whose lines it shows, and, just as usefully, whose it does not. What follows walks through the system the way the statute assembles it: not as a list of steps, but as a cast of parties, each with a defined part — the excavator, the corporation in the middle, and the owners of the lines — because once you know who is who, the marks on the grass stop being a warning and become a map you can actually read.

You, in the Eyes of the Act: the “Excavator”

Start with the party the reader is: yourself. The statute does not have a separate, gentler category for a homeowner doing a small job by hand. It has one word — excavator — and it is defined broadly. An excavator is any individual, partnership, corporation, public agency or other person or entity that digs, bores, trenches, grades, excavates, moves or breaks earth, rock or the material in the ground (s.1).

Two features of that definition matter for someone standing in their own backyard. The first is any individual: the role does not turn on whether you are a contractor, whether money changes hands, or whether the hole is large. A person setting a fence post is doing the same listed act — breaking earth — as a crew running a trench. The second is subtler and easy to miss: the definition also reaches anyone who intends to do any of those things. The role attaches at the planning stage, not at the first cut of the shovel. So the question is never whether the rules apply to a homeowner; the Act has already answered that by naming you. The only open question is what the role asks of you, and to see that you have to meet the other parties.

Ontario One Call: the Corporation in the Middle

The second party is the one you actually contact — the Corporation the Act refers to, which operates as Ontario One Call. It is continued under the statute as a corporation without share capital (s.2(1)), and the Act is explicit that it is not an agent of the Crown (s.2(5)). In plain terms, it is a single, province-wide clearing house that sits between you and everyone who owns a buried line.

Your locate request goes to the Corporation, not to each utility one by one. A locate request, as the Act defines it, is a request by an excavator to the Corporation for locates of all underground infrastructure that may be affected by the dig (s.1), where the infrastructure covered runs the full range of buried services — water, gas, electricity, communications, cable, internet and sewer among them. The Corporation takes that single request and relays it onward to the owners whose lines could sit in the way. And it does so at no cost to you: the Corporation is prohibited from charging an excavator anything for submitting a locate request (s.5.1(4)). The party in the middle is deliberately free to use, so that the price of asking is never a reason not to ask.

The Members: Who Owns the Lines Under Your Lawn

The third party is really a whole roster. The Act calls anyone who owns or operates underground infrastructure a “member,” and the list of who must be a member is long (s.5(1)): every municipality in Ontario; Hydro One; Ontario Power Generation; every natural-gas distributor and transmitter; every operator of an electricity distribution system; parties regulated under the Oil, Gas and Salt Resources Act; and every person or entity that owns or operates underground infrastructure crossing or next to a public right of way. When the Corporation relays your request, these are the parties on the receiving end.

A member that gets notified is not free to ignore it. It has to do one of two things (s.6(1)): either mark the location of its underground infrastructure on the ground and give you a written document with the location information, or tell you in writing that its infrastructure will not be affected. Those written “not affected” answers matter as much as the paint — a clear statement that there is nothing of theirs to hit is itself part of the response.

The Act also puts a clock on the member. For a standard request, a member has 5 business days after being notified to complete that response (s.6(3)), though the parties can agree in writing to a different period and a regulation can set one as well (s.6(5), s.6(6)). A separate, faster track exists for genuine emergencies: where the situation involves an interruption of an essential service, or could reasonably be expected to cause an imminent safety or environmental hazard or a threat to a person or the public, the member must attend or respond in writing within 2 hours (s.6(4)) — and the Act guards against using that lane for ordinary jobs (s.12(2)). Like the request itself, the member’s locate is free: a member cannot charge for responding to a locate (s.6(7)).

The Line the System Draws — and the One It Does Not

Follow the private-line point through, because it is where a backyard dig can go past what the statute covers. The duty in s.6(1) is tied to the word its: a member marks the infrastructure it owns or operates. What a utility owns or operates is the member’s to locate. But a line you laid yourself is a different thing — the buried electrical run out to a detached garage or shed, a gas line taken to a backyard barbecue or pool heater, low-voltage lighting or an irrigation feed. Those are not a member’s infrastructure, so nothing in s.6(1) requires anyone in the locate system to mark them.

This is a limit of the roster, not a flaw in your request. The Corporation relayed the request; the members answered for their own lines; the paint on the grass is a faithful map of member-owned infrastructure. It is simply not a map of everything buried. For the private lines, the responsibility loops back to the party who has it all along — you, as owner. Confirming where your own buried lines run before you dig, or arranging a private locate for them, sits outside what the members are required to do. On what any specific private line is, or how to trace it safely, the practical step is to speak to a qualified locate provider or the relevant trade; this article describes the roles the Act assigns, not a diagnosis of your particular property.

Before the Shovel: What s.10 Requires, and How Long a Locate Lasts

With the parties in place, the Act sets the gate the excavator has to pass before breaking ground. Under s.10(1), you must not begin to dig unless one of two conditions is met. The first: you have submitted a locate request, every member that may be affected has completed its s.6(1) response — a marking with the written information, or a written statement that it is not affected — and, where markings were placed, you have confirmed that the marks on the ground and the written information do not conflict with each other. The second route lets you rely on locate information another excavator already obtained for the same dig parameters, including the same geographic area, under s.11 — but the same conflict check applies before you start.

Two details are worth holding onto. A locate does not last forever: the Act provides that the information has a validity period, and once it has expired you cannot keep digging on it — a fresh request is needed (s.10(2)). The length of that period is fixed by regulation, so I am not stating a number here. And at the other end, you cannot submit a standard request too far ahead: a standard locate request may not be made more than 30 days before the anticipated start of the excavation (s.12(1)). The window has a front edge and a back edge, and the shovel belongs inside it.

When Something Goes Wrong: Who Answers to Whom

The last thing to map is the responsibility that runs between the parties, because it does not all flow one way. The Act gives each side a claim against the other when its duty is broken.

The excavator toward the member. An excavator who breaches the 30-day timing rule in s.12(1), or who digs in a way the excavator knows or ought to know will damage or interfere with underground infrastructure (s.13) and causes damage or interference, is liable to compensate the member for the resulting loss or expense, including economic or financial loss (s.16(1), s.16(2)). Those amounts can be settled between the parties, and where they cannot agree, the matter is decided by the Ontario Land Tribunal (s.16(3), s.16(4)).

The member toward the excavator. The claim runs back the other way too. A member that locates its infrastructure inaccurately, wrongly states that its infrastructure will not be affected, or fails to provide the locate within the s.6 timeline can be liable to the excavator for the loss that results (s.17).

The penalties the Act attaches. Two separate consequences exist beyond compensation. An assessor may impose an administrative penalty on a member or an excavator for contravening a provision the Minister’s regulations designate; each such penalty cannot exceed $10,000 (s.17.2, s.17.2(4)), and it is an absolute-liability matter — taking reasonable steps, or an honest and reasonable but mistaken belief in the facts, is not a defence (s.17.2(7)). Separately, any person other than the Corporation who contravenes the Act or its regulations is guilty of an offence and, on conviction, liable to a fine of not more than $10,000 (s.18). That is the extent of what the statute sets out — no more than the Act itself provides.