What Do the 811 Color Codes Mean in California?

In California, the 811 color codes are the standardized paint and flag colors utility companies use to mark their buried lines before you dig: red for electric, yellow for gas and other flammable or petroleum products, orange for communications, blue for potable water, green for sewer and drain, purple for reclaimed water and irrigation, pink for temporary survey marks, and white for the excavation area you outline yourself before the locators arrive. The colors come from the American Public Works Association’s uniform code, and California law requires operators to use them when field-marking their installations.¹

What Each Color Marks

Red — electric power lines, cables, and conduit
Yellow — gas, oil, steam, or other petroleum and gaseous materials
Orange — communication, alarm, or signal lines
Blue — potable water
Green — sewer and drain lines
Purple — reclaimed water, irrigation, and slurry lines
Pink — temporary survey markings
White — the proposed excavation area, placed by the excavator

If you see several colors clustered in the same strip of ground, that is a real pattern, not a mistake. Gas, electric, and water lines commonly share the same easement and run parallel to each other. Treat an area with overlapping marks as the most sensitive part of your dig.

Who Places the Marks

Every color except white and pink is placed by the utility operator after you’ve opened a ticket with the regional notification center. White is yours. You spray or flag the outline of your planned dig area before you call, so the locators know where to focus; if you skip this step, called delineation, an operator can decline to mark anything until you’ve done it.²

Pink marks are a separate category. They come from surveyors and have nothing to do with buried utilities. Finding pink on the ground tells you a survey crew has been through, not that anything is or isn’t underneath.¹

How Close You Can Get With Power Equipment

Knowing what the colors mean only matters if you also know how close you can dig to them. California defines a “tolerance zone” that extends 24 inches on each side of every operator mark.³ A yellow paint line showing a gas pipe gives you a tolerance zone two feet wide on either side of that line, four feet total.

Inside that zone, you cannot use power-driven excavation or boring equipment until you’ve located the line by hand and know exactly where it sits. No backhoes, no trenchers, no augers. Hand tools only.⁴

There is one alternative. A vacuum excavation device may be used within the tolerance zone, but only if you told the notification center you intended to use one when you opened your ticket, and the operator agreed. If the operator didn’t agree, their electronic positive response will say so, and you’re back to hand tools.⁴

Treat every buried line as active, even one you believe is abandoned. The law requires the same care around an inactive line as a live one.⁴

If Hand Digging Doesn’t Find the Line

If you’ve exposed soil within the tolerance zone and still can’t locate the installation, you can ask the operator for additional information. They must provide whatever relevant records they have within one working day. You can also go back through the notification center, which will give you the operator’s phone number so you can coordinate directly.⁴

How to Get the Marks Placed

California has two regional notification centers, split geographically. USA North 811 covers Northern California and DigAlert covers Southern California. You reach either by dialing 811 or by submitting an online ticket through their websites. The center cannot charge you a fee for submitting or renewing a ticket.⁵

The sequence is: delineate your dig area in white, open the ticket, then wait. You must notify the center at least two working days before you plan to dig, and the day you call does not count. You also can’t call more than 14 calendar days in advance; projects further out than that have to wait.²

You cannot start digging until every operator on your ticket has responded, either by marking their lines, providing location information, or confirming they have no facilities in your dig area. Call on Monday and your earliest legal start is Wednesday, assuming all operators have responded by then. You and an operator can agree to a different timeline, but the two-working-day default applies unless both sides sign off on a change.²

Tickets stay valid for 28 calendar days from the date of issuance, not the date you start digging. If your project runs longer, renew the ticket before it expires. Projects stalled by permitting delays or weather are the ones that most often lose track of this.

Emergencies

The two-working-day rule does not apply in emergencies. California law allows excavation to begin immediately when an emergency exists, though the statute does not define the specific criteria for what qualifies. The exception runs through several subsections of Government Code 4216.2, including the general notification rule and the requirement to wait for operator responses.²

If You Hit a Line

Call 911 immediately if you damage a gas or hazardous liquid pipeline and cause a leak of flammable, toxic, or corrosive material. The same applies to any damage involving a high-priority subsurface installation: high-pressure natural gas pipelines operating above 60 psi, petroleum pipelines, pressurized sewage lines, electrical conductors at 60,000 volts or more, and hazardous materials pipelines.⁴

In practical terms, that means a nicked yellow or red mark area is not something to assess on your own. Clear the area and get emergency responders on scene.

Lines the Colors Won’t Cover

The 811 system covers utilities in the public right-of-way and the connections running from the main line to your property. Lines that run entirely on private property, such as a gas line from your meter to a pool heater or irrigation pipes crossing a yard, are generally not covered by the regional notification centers. If you know private lines exist in your dig area, a private utility locator can mark them; hourly rates typically range from $95 to $175 depending on site complexity and how many utilities are involved. Worth factoring in before you break ground on a backyard project where the main-line marks will stop at the meter.

1
American Public Works Association. Uniform Temporary Marking of Underground Facilities
2
California Legislative Information. California Code Government Code 4216.2
3
California Legislative Information. California Code GOV – Government Code
4
California Legislative Information. California Code Government Code 4216.4
5
California Legislative Information. California Code Government Code 4216.1