Never assume it’s safe to excavate

Did you know there were more than 2,400 reported damages to underground Enbridge Gas infrastructure last year? The majority of these damages were due to unsafe excavation practices. 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—and it’s the law. Respect the marks and dig safely.

Following the rules ensures contractors return home safe to their families. Watch our video to see more.

Contractor requirements

The Technical Standards and Safety Authority (TSSA) and other government regulators refer excavators to Enbridge Gas requirements for safely operating near our service lines. They are also used as a reference in the case of excavators causing damages due to unsafe digging.

Safe excavators get recognized

Each year, Enbridge Gas recognizes companies that practice the highest standard of safety when excavating around natural gas lines. The Award of Excellence for Excavating is given to those that submit 500 or more locate requests to Ontario One Call and avoid damaging any natural gas infrastructure. This year, 127 winners were recognized.

“Contractor relationships are important to us. Enbridge Gas is here to help empower contractors to dig safely; it’s in the best interest of everyone involved.”

Chris Van Daele, Supervisor of Distribution Protection

Congratulations to the winners of the Enbridge Gas 2021 Award of Excellence for Excavating, including:

NuBuild Contracting Inc.

“We take great pride in what we do on a daily basis and this is definitely a big milestone for us. We look forward to many more years of being damage-free.”

Michael Guerriero, Project Manager, NuBuild Contracting Inc.

Powell Contracting Ltd.

“Safety is one of four core values of our company. We also have a dedicated locates department. The locates department keeps things highly organized for the entire operations team.”

Rupee Dhillon, Senior Locate Specialist, Powell Contracting Ltd.

Royal Oak Tree Services

“It is very important to keep everyone safe and not focus just on the fines. Just take time, plan, organize, and please keep everyone safe."

Nerea Garcia Nieto, Senior Office Manager, Royal Oak Tree Services

Damaging a natural gas line has serious consequences


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

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

Wait for buried lines to be marked

Locate representatives 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 completed, follow the instructions and proper excavation practices to ensure a safe and smooth project.

Learn from these incidents

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. This may also be received as an email that will need to be printed out and kept on-site. Check that the document matches the flags/paint markings on the ground before starting any work.

Keep a safe clearance from locate marks

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. Do not assume the depth of the line—take care with shallow shovel scoops.

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.

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 30 metres 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 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.

Only locate requests where a field locate (paperwork and ground markings) is completed by Enbridge Gas will be subject to this charge. Locates requested by property owners, for a property where they or their tenant reside, will not be subject to this charge. 

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.