Call 811: Utility Locating
Striking a buried gas line, power cable or fiber line can cause explosions, electrocution, outages and huge repair costs. Calling 811 before you dig is free, and it’s the law in every state.
- Construction
- Landscaping
- Utilities
How it works
- Call 811 (or submit online) a few business days before digging. The exact notice time is set by your state.
- Mark the proposed dig area in white paint if your state requires it.
- Utility owners send locators to mark their lines with paint or flags.
- Wait for all utilities to respond before digging. Check your ticket.
- Dig carefully within the tolerance zone (often 18 to 24 inches on each side of the marks, depending on the state) using hand tools or vacuum excavation.
Your ticket
- Each ticket covers a specific area. If you dig outside it, you need a new ticket.
- Tickets expire. The time varies by state. Long jobs need tickets renewed.
- Marks fade and get dug up or paved over. Request a re-mark if you can’t see them, and protect the marks you have.
- Positive response: many states let you check online whether each utility has marked or cleared the area. Don’t dig until every utility on the ticket has responded.
- Emergencies: states have emergency locate procedures for urgent repairs, but you still must call.
What marks don’t tell you
- Depth. Marks show the approximate horizontal location only. Depth changes with grading, erosion and how the line was installed.
- Exact location. That’s why the tolerance zone exists. The line can be anywhere inside it.
- Size. Some marks include the line’s width or type; many don’t.
- Abandoned lines may not be marked, and may still be live.
Color codes
| Color | Utility |
|---|---|
| Red | Electric power lines, cables, conduit |
| Yellow | Gas, oil, steam, petroleum |
| Orange | Communications, telephone, cable TV, fiber |
| Blue | Potable (drinking) water |
| Purple | Reclaimed water, irrigation |
| Green | Sewer and storm drains |
| Pink | Temporary survey markings |
| White | Proposed excavation |
811 doesn’t mark private lines such as sprinkler systems, private electric to outbuildings, or lines past the meter. You may need a private locator.
Report every hit
If you scrape, dent, nick or pull a line, even slightly, stop and call the utility owner. A small nick in a gas line’s coating or a scraped cable jacket can fail months later. Most states require you to report any damage. Don’t backfill over a damaged line. See What to Do After a Utility Strike.
Homeowners too
811 isn’t just for contractors. Planting a tree, installing a fence post or mailbox, or building a deck can hit a gas or electric line. The call is free.
If you hit a gas line: stop, shut off equipment if safe, get everyone away and upwind, don’t use anything that could make a spark, call 911 and the gas company. Don’t try to stop the leak.
Standards & references
- 811 Before You Dig (Call811)
- 29 CFR 1926.651(b): Underground installations
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