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Call Before You Dig: Who to Contact in Every Province and State

Before you dig, you must know what is under the ground. Gas lines, power cables, water mains and phone lines can be just under the surface. Hitting one with a loader, backhoe, skid steer or even a shovel can cause a fire, an explosion, electrocution or a flood. It can also cut service to a whole neighbourhood.

The fix is simple and free: ask for a locate before you dig. You contact one centre, and it tells every utility in the area. Each utility then marks its lines on the ground, or tells you it has none there.

What the Law Says

In the US, OSHA 29 CFR 1926.651(b) requires the employer to find out where underground utilities are before any excavation starts. In Canada, provincial rules say the same, for example Ontario Regulation 213/91, section 228, and the BC OHS Regulation, section 20.79. In Ontario, the law also says you must contact Ontario Dig Authority before you dig. Work near a marked line must follow the owner’s rules, and any damage must be reported to the owner right away.

The Steps

1. Ask a few working days ahead. Contact the centre for your province or state, online or by phone. The Canada table shows how much notice each province needs; in the US, your state centre’s website gives the rule.
2. Wait for the marks. Don’t dig until every utility has marked its lines or told you the area is clear.
3. Respect the marks. Dig by hand close to a mark. Never dig with a machine right on top of a marked line.
4. Keep the marks fresh. Marks only last a set time, and rain or traffic can wipe them out. If the marks are gone, too old, or your job changes, ask for a new locate.
5. If you hit a line, stop. Move back if it is safe, keep people away and call the line’s owner. For gas, or a downed or damaged power line, call 911 first.

What the Colours Mean

Utilities mark their lines with paint, flags or stakes in these standard colours:

• Red: electric power
• Orange: communication (phone, cable, fibre)
• Yellow: gas, oil or steam
• Green: sewer and storm drains
• Blue: drinking water
• Purple: reclaimed water, irrigation and slurry
• Pink: temporary survey marks
• White: where you plan to dig (you can mark this yourself)

Canada: Your Provincial Centre

Canada has no single number. Contact the centre for the province where you will dig, or start at ClickBeforeYouDig.com, which links to every provincial centre.

Yukon, the Northwest Territories and Nunavut have no locate centre. Contact the owner of each line directly: the power, gas, phone and cable companies, and the local government for water and sewer.

United States: Call 811

Call 811 from anywhere in the US. Your call goes to the centre for the state you call from. You can also ask for a locate online on your state centre’s website. If you will dig in another state, contact that state’s centre directly. Most states need 2 or 3 working days’ notice, not counting weekends and holidays; your state centre’s website gives the exact rule.

Check Before Every Job

Centre names, websites and rules change. Ontario One Call, for example, is now Ontario Dig Authority. We checked every centre in this article in November 2026. Always confirm the rules with the centre before you dig.

NIS Training’s loader programs teach operators to plan every dig safely, from locates to trench edges. To learn more, call us at 1-866-344-3950 or visit nistraining.com.