Call 811 before you dig: what the paint colors mean

One free call, every time

Whether you’re replacing a lateral, installing a cleanout, or planting a tree near the line, the rule is the same: call 811 first. It’s a free, federally mandated service. You call (or file online) a few business days ahead, and every utility with buried infrastructure sends a locator to mark their lines on your property with paint and flags.

This isn’t optional politeness. Digging without a locate is illegal in every state, and if you strike a gas or electric line you’re liable for the repair, the outage, and any injury — a bill that dwarfs the sewer job you started with.

What the colors mean

Locators use a national color code (the APWA standard) so anyone on site can read the ground at a glance. Your sewer and drain lines are marked green; potable water is blue. The rest tell you what else is down there to avoid.

After the marks appear

Locates only cover public utilities up to the meter — your private lateral, sprinkler lines, and any owner-installed conduit usually aren’t marked, so a camera inspection that locates the pipe is still worth it. Respect the marks: most states require hand-digging within an 18–24" tolerance zone on either side of a painted line.

The marks are temporary. If your project slips past the locate’s validity window (often 14–28 days), call 811 again before you break ground.

Use the tool: Repair cost calculator →