811 Call Before You Dig: What It Covers and What It Misses
Call 811 — or your provincial one-call centre in Canada — before every dig. Then understand precisely what the ticket did and did not cover, because that gap is where most private-property strikes happen.
How 811 Works
811 is the national number for the United States one-call system. You submit a ticket by phone or through your state's portal with the dig location, scope, and timing. The center notifies every member facility owner with registered infrastructure in that area, and each one sends a locator to mark the lines it owns with paint and flags in the APWA color code. In Canada the equivalent is a provincial network — Alberta One-Call, BC 1 Call, Info-Excavation in Quebec, Ontario One Call and their counterparts.
Notice periods are set by each state or province. Utility Hotline displays the program, the number, and the required notice on every state and city page.
Wait for Positive Response
Filing the ticket is not the same as being clear to dig. Each notified member posts a status back — marked, no facilities in the area, or more time needed. Digging before every member has responded means digging without knowing whether the silence is "nothing here" or "nobody has been out yet". Most programs give you a way to check response status online, and checking it is part of the job.
What 811 Marks
Lines owned by member facility owners: typically natural gas, electric, water, sometimes sewer, and major telecommunications and cable plant. Membership varies by state, so who responds is not identical everywhere. The marks indicate approximate horizontal position only. Depth is not part of the deliverable, and a mark is an approximation with a legally defined tolerance zone around it, not a survey line.
What 811 Does Not Mark
- Service lines past the meter — water, gas, and electric on the owner's side of the boundary
- Site lighting, sign, and parking-lot circuits
- Irrigation mains, laterals, and valves
- Private sewer and septic laterals
- Campus and industrial distribution between buildings
- Farm drain tile and private well and pump services
- Lines owned by non-member utilities, where the state permits non-membership
- Abandoned lines that dropped out of the service records
That list is the entire product of the private locating trade. It is not an edge case — on any dig that happens on private property, it is most of what is in the ground.
White Lining Improves What You Get Back
White is the APWA color reserved for proposed excavation. Outlining your dig area in white paint or flags before you submit the ticket tells every responding locator exactly which ground matters, so they sweep it properly instead of marking a whole street frontage from an address. The marks that come back are tighter and more usable, and several programs require white lining for large or ambiguously described excavations.
The APWA Color Code
- Red — electric power, cables, conduit, lighting
- Yellow — gas, oil, steam, petroleum
- Orange — communication, alarm, signal lines
- Blue — potable water
- Green — sewer and drain lines
- Purple — reclaimed water, irrigation, slurry
- Pink — temporary survey markings
- White — proposed excavation
Private locators use the same code, so private and public marks sit side by side on the ground and mean the same thing.
Frequently asked questions
Is calling 811 free?
Yes. Notification is free to the excavator, and the member utilities fund the system. Failing to notify before excavation exposes you to penalties set by state or provincial law and to full liability for any damage that follows.
Does 811 cover private property?
Partially. Member utilities will mark the lines they own even where those lines cross private property, which usually means up to the meter. Everything past the meter belongs to the property owner and is outside the ticket entirely. On a residential lot that typically includes the irrigation, the sewer lateral, the yard gas run, and any circuit feeding a garage, shed, or light pole.
How long are marks good for?
One-call programs set their own validity windows and require a re-mark request when work runs past them, so check the rule for the state or province you are digging in. Physically, paint and flags do not survive rain, traffic, or a construction season. Treat marks as good only while you can still read them.
What happens if I dig without calling?
You take on full liability for any damage, plus whatever civil penalty the jurisdiction sets. Damage to a gas line can escalate beyond a civil matter. Beyond the legal exposure, the practical problem is that you have no defensible record of having done the one thing every damage-prevention regime is built around.
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