California law requires that you call 811 at least two business days before starting your excavation project. Here are the steps you need to take:
Call 811 at least two business days before you dig—the service is free.
Identify and mark your digging area with a white substance such as chalk, spray paint, flour or marking whiskers, tags, stakes or any combination.
PG&E and other companies will use colored utility flags, stakes or paint to mark underground lines following the American Public Works Association Uniform Color Code (PNG, 130 KB). Please leave the marks in place until you are finished digging. The marks are valid for 28 days.
Only use hand digging tools, such as shovels, within the 24-inch zone. After finishing your project, carefully backfill and compact the soil.
You can spot PG&E's larger transmission pipelines by looking for pipeline markers. They specify the approximate or offset location; however, not all pipelines follow a straight path between markers. These markers also indicate the need for extra care when digging in the area.
Use our interactive online map to find out if there are natural gas transmission pipelines in your area.
Our bright yellow markers indicate a natural gas transmission pipeline is nearby, and display our 24-hour emergency gas hotline number.
We created this first-of-its-kind excavation safety program to reduce accidents and protect underground gas and electric systems.
Post these informative posters in the workplace and on the jobsite to remind workers that it’s necessary to call 811 before digging.
Download English posters
Contractor gas safety poster (PDF, 10.7 MB)
Markings brochure (PDF, 1.1 MB)
Download Spanish posters
Folleto sobre seguridad para contratistas (PDF, 423 KB)
Folleto sobre marcaciones (PDF, 1.1 MB)
Common Ground Alliance is a member-driven association committed to saving lives and preventing damage to underground infrastructure by promoting effective damage prevention practices.
Please report any signs of a gas leak immediately.
We add a distinctive, sulfur-like, rotten egg odor so you can detect even small amounts of natural gas. However, DO NOT rely only on your sense of smell to detect the presence of natural gas.
Pay attention to hissing, whistling or roaring sounds coming from underground or from a gas appliance.
Be aware of dirt spraying into the air; continual bubbling in a pond, creek, puddle or other source of standing water; as well as dead or dying vegetation in an otherwise moist area.