Call 811 first — before any dig
Before you put a shovel, post-hole digger, auger, or stake into the ground, make one call: 811. It’s the national Call Before You Dig number, and it’s free. You can dial 811 from anywhere in the US, or file the request online at your state’s 811 center (also called a One Call or notification center). You tell them where you’re digging and what you’re doing, they give you a ticket number, and then the utilities send locators to come mark their buried lines across your dig site — at no charge to you.
This applies to far more than the big jobs. A fence post, a deck footing, a mailbox, planting a tree or a shrub, edging a garden bed, setting a basketball hoop — all of it is digging, and all of it can hit a line. The reason to bother is blunt: buried gas, electric, and other lines are often much shallower than people assume, and striking one is not a small mistake. Hitting a gas line can cause an explosion; hitting an electric cable can be a fatal shock. And if you dug without calling 811, the repair bill — and the liability — lands on you. One free call moves all of that off your shoulders.
What 811 is, and why it’s free
811 exists because unmarked digging is the single biggest cause of damage to buried utilities in the country, running to billions of dollars a year. So the system was built to be as frictionless as possible: one number, every state, no fee. When you call, your request goes to every utility that has lines in your area, and each one is legally required to send someone to mark its lines — or to tell you it has none there — within your state’s set window.
The “free” part is worth being clear about, because people assume there’s a catch. There isn’t, for the public lines. The gas main and service line, the electric feed, the water and sewer mains, the phone and cable lines — the utility owns those up to your meter, and marking them is on the utility, not you. You never pay 811, and you never pay the locator. The only time money enters the picture is if you hire a private locator for lines that 811 doesn’t cover, which is a separate thing covered further down.
How long it takes, and what to expect
Here’s the part that trips people up: 811 is not a same-day service, and it is not an emergency line. You place the request a few business days ahead — commonly about two to three business days, though your state sets the exact wait, and weekends and holidays don’t count. Then you wait for the site to be marked before you dig.
So plan it into the project. If you want to dig on Saturday, don’t call Friday afternoon — call earlier in the week. When the locators come (you usually don’t need to be home), they mark their lines with paint and flags directly on the ground, and they mark only within the area you described, which is why outlining your dig site in white first helps them. Once everything is marked and your state’s waiting period has passed, you’re cleared to dig — carefully, around the marks.
If you ever have an actual emergency — a line already struck, gas already leaking — that is never an 811 call. That’s 911 and the utility, immediately.
The color code: what the marks mean
The paint and flags follow a standard color code, so once you know it you can read the ground at a glance:
- Red — electric. Power lines, cables, conduit, lighting cable. Treat these as the most dangerous to strike.
- Yellow — gas. Also oil and other flammable or explosive material. A yellow line is a leak-and-explosion risk.
- Orange — communications. Telephone, cable TV, fiber, alarm and signal lines.
- Blue — potable water. Your drinking-water line.
- Green — sewer and drain lines.
- Purple — reclaimed water, irrigation, or slurry lines.
- White — the dig site itself. This is the area you plan to excavate, and you can outline it before the locate so the crew marks the right ground.
The colors aren’t decoration — they tell you what’s below and how much care each mark demands. Red and yellow especially mean slow down and hand-dig.
What counts as “digging” (shallower than you think)
People underestimate this two ways. First, they think only big excavation counts — it doesn’t; a hand trowel can cut a shallow gas line. Second, they assume lines are buried deep — they often aren’t. Utilities can sit only inches below the surface, shifted over the years by erosion, regrading, or a sloppy original install. That’s why a garden bed or a mailbox hole is enough to reach one.
So the test isn’t how deep or how big your project is. If you’re disturbing the ground at all — digging, trenching, augering, driving a stake or a post, even grading — call 811 first. The service’s own rule is the right one to adopt: every dig, every time.
What 811 does not cover: your private lines
This is the most common and most dangerous gap in people’s understanding. 811 locators mark the utility’s lines, up to your meter. They do not mark private lines — the ones you, a contractor, or a previous owner installed and now own. Those are invisible to the 811 system, and they’re frequently the ones a homeowner hits, precisely because no one marked them.
Private lines you have to locate yourself include:
- A gas line you ran to a grill, fire pit, pool heater, generator, or a detached garage or shed.
- An invisible / electronic dog fence.
- Low-voltage landscape lighting and its wiring.
- A private water line to a barn, well, sprinkler system, or outbuilding.
- Septic tanks and their drain-field laterals.
For any of these, you hire a private utility locator — a paid service that does the same kind of scanning 811 triggers, but for the lines the public program won’t touch. If you know you’ve got a gas line to the grill or wiring out to the yard, budget for a private locate on top of your free 811 call. It’s the difference between a marked line and a very bad afternoon.
Hand-dig near the marks — the tolerance zone
Getting your lines marked isn’t a green light to swing a blade right up to the paint. The marks show roughly where a line runs, not its exact path to the inch or how deep it sits. So there’s a buffer called the tolerance zone — typically about 18 to 24 inches on either side of a mark — where you put the power equipment away and dig by hand.
Within that zone, dig carefully, expose the line gently, and work around the marks rather than on top of them. If you expected a line and can’t find it, or the marks don’t match what you’re seeing underground, stop and call your 811 center rather than forcing a shovel or blade in blind.
If you hit a line anyway
Even careful diggers occasionally strike something. What you do in the next few seconds matters more than anything else, and it depends on what you hit.
If it’s a gas line — you nicked, dented, scraped, or broke it, or you smell gas or hear hissing — leave the area immediately, on foot, and get well upwind. Don’t start a car, use a phone at the site, flip a switch, or do anything that could make a spark. From a safe distance, call 911 and your gas utility’s emergency line. Don’t try to stop the leak or go back to move your tools. (For the full smell-gas response, see smell of gas in the house.)
If it’s an electric cable — you hit buried power line, cable, or conduit — do not touch the line, your tool, or anything the line is in contact with, and keep everyone else back too. If you’re on equipment that’s contacting the line and can stay put safely, stay on it; if you must get off, jump clear without touching machine and ground at once. Call 911 and your electric utility. Treat it exactly like a live wire, because it is. See a downed power line for how to keep clear while you wait.
Even a minor hit gets reported. A dented pipe, a scraped cable coating, a small nick that isn’t leaking or sparking — call the utility anyway. Damage that looks harmless today can corrode, weaken, and fail weeks later. Never quietly backfill over a line you’ve damaged. Report it, let the utility inspect and repair it, and you’ve turned a near-miss into a non-event instead of a future emergency.