Never assume it’s safe to excavate

Did you know that 41 percent of damages to underground infrastructure are due to unsafe excavation? Whether it’s a small landscaping job or a major construction project, hitting an underground utility can delay your project and put your crew, company and community at serious risk. You could also be accountable for costly repairs and even face serious penalties or charges.

It’s your responsibility to request a locate from Ontario One Call before you dig—it’s free and it’s the law. Respect the marks and dig safely.

Damaging a natural gas line has serious consequences

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Seriously hurting yourself or coworkers.

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Incurring expensive legal and repair costs, serious penalties and charges.


Losing productivity by bringing your project to a stop.


Jeopardizing future contracts and your reputation.

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Interrupting natural gas service to the neighbourhood.

Follow these steps to dig safely


Submit your locate request

Call 1-800-400-2255 or visit at least five business days before you start your excavation.


Wait for buried lines to be marked

Locators from each underground infrastructure owner will come out to mark your job site with locate flags or temporary paint. Enbridge Gas locates are only valid for 60 days.


Respect the marks and dig safely

Once locates have been made, follow the instructions and proper excavation practices to ensure a safe and smooth project.

Real damage, real stories

Why is it so important to dig safely around natural gas lines, even with a locate? Hear directly from professional excavators, contractors and damage inspectors about what can go wrong—and why it’s not worth the risk.

Tips for safe excavation around natural gas lines


Have your locate information on-site

Your locator will provide you with a locate sheet identifying the work area. Check that the document matches the flags/paint markings on the ground before starting any work.


Keep a safe clearance from locates

Keep a one-metre safety clearance on either side of your locate marks. This is known as the “tolerance zone”.


Always dig around a natural gas line by hand first

If you’re digging in the tolerance zone, you must use a shovel or hydrovac to carefully expose the natural gas line before digging with heavy equipment.


Support the natural gas line

Install a temporary steel or wood support system to prevent the natural gas line from bending or sagging during excavation.


Shore up appropriately

For deep trenches, place boards or other bracing against the excavation walls to prevent the trench from collapsing and damaging lines.

Know the colour codes

Locates show the direction and approximate location of the natural gas line, but do not show their depth. A natural gas line could lie just a few inches below the surface.

Yellow: Natural gas, oil, steam
Green: Sewer, storm
Red: Electric
Orange: Communication
Blue: Water
Purple: Irrigation, slurry
Pink: Temporary survey markings
White: Proposed excavation

Become a certified expert to add value to your company

Sign up for Ontario One Call’s online Professional Locate Administrator Course (PLAC). Through nine interactive modules, you’ll learn how to effectively manage locates and keep your crew and your community safe.

What to do if you damage a natural gas line or smell gas

  • Stop work and shut off all tools, machinery or equipment.
  • Clear everyone from the area.
  • Call 911.
  • Contact Enbridge Gas immediately at 1-866-763-5427.
  • Do not attempt to control or stop the gas from escaping.


Our Third Party Requirements in the Vicinity of Natural Gas Facilities Standard provides guidelines for third-party operators working in the vicinity of our infrastructure. This standard will outline technical requirements that aim to protect the safety of our contractors and our underground infrastructure.

Additional resources

Planning work near vital pipelines?

When you request a locate from Ontario One Call, the locate service provider may identify that a vital natural gas pipeline is within 30m of the proposed work area. Legally, you can't begin work until a you obtain a clearance.

Planning a project? Contact Ontario One Call

You must call at least five business days before you begin work. Never break ground without locates to guide you.

Frequently asked questions

Locates are colour-coded ground markings identifying the approximate position of underground lines and cables on a proposed job site. They’re made using temporary paint or flags and are always accompanied by a locate sheet that maps out where lines are buried in relation to fixed objects such as poles, buildings or sidewalks.

By law, a locate is required any time you’re breaking ground on a project.

Whatever company is completing the excavation is responsible for obtaining locates, regardless of who owns the property or who contracted out the work. If there are multiple excavators working on one site, you may add multiple company names to the locate request.

To get a free locate, submit your request via the Ontario One Call contractor portal at or call 1-800-400-2255.

Ontario One Call will notify all owners of buried infrastructure on your behalf. These include electric, water, sewage and natural gas utilities, as well as telecommunication companies.

Utility locates are a free service. There’s no cost to you. Any privately owned infrastructure, such as a gas line that runs from a meter to a pool heater or barbecue, won’t be covered under the Ontario One Call request. A private locate company will need to be hired to mark these lines and there is a charge for this service.

A utility locate request must be made no less than five business days prior to the planned start date of your project. By law, you must have both paint markings and your locate sheet finalized before starting any work.

You’ll need to provide Ontario One Call with your company name and address, your client’s information, your dig location, project start date, a description of the project, the type of project being completed, how you plan to dig (shovel, excavator, etc.) and how deep you plan to dig.

A qualified utility representative will visit your job site and mark the location of all underground cables and pipes. They do this by painting or inserting flags in the ground along the path of the pipe or cable. They’ll also provide accompanying paperwork and locate drawings so you can verify that the ground markings match the information provided in the drawings.

You can check the status of your request on the Ontario One Call web portal. Owners of buried infrastructure will mark the status of their lines as either “clear” or “complete.” A clear status means there’s no risk and that your proposed digging area is safe. A complete status means the locate has been marked on your job site. All utilities must be marked as either clear or complete to proceed.

The actual location of the buried line may be within 1 metre on either side of the paint or locate flags placed on your job site. This is referred to as the tolerance zone. When digging in the tolerance zone, you must first use a shovel or hydrovac to expose any hidden pipes before using machinery.

If there is any doubt about the location of underground natural gas lines, contact Enbridge Gas as soon as possible. A member of the Damage Prevention team will come out to the site to verify the position of the locates and provide you with the information you need to excavate safely. This is a free service.

Moving or removing locates makes them invalid and you’ll be liable for any damage that occurs. You must call Ontario One Call to arrange a new locate before you start excavating.

An Enbridge Gas locate is valid for 60 days from the date that the locate was completed. If you have not finished excavating within those 60 days, a new locate is required.

Yes, if you damage an underground utility as a result of not following safe excavation guidelines on the job site, you’ll be responsible for the full cost of labour and materials to repair the infrastructure and could incur additional penalties and serious charges.

If you smell rotten eggs, hear an unusual hissing sound, or see dust or leaves blowing in a localized area, you may have damaged a natural gas line. You may also see a physical puncture or gouge on the line.

If you think you’ve hit a natural gas line, stop work immediately and shut off all equipment to avoid ignition. Do not attempt to control the release of gas yourself. Evacuate the job site and surrounding area, call 911 from a safe distance away and contact Enbridge Gas immediately at 1-866-763-5427.