Planting a tree, setting fence posts or trenching for irrigation all put a shovel into ground that may hold gas, electric, water or communication lines. In California, the rule is simple. Call 811 before digging so utility operators can mark their lines first.
The process has clear steps and timelines. Knowing them helps a yard project start on schedule and safely.
What 811 Does
USA North 811 describes 811 as a free national service designed to keep people and communities safe. It says the service is for professional excavators, homeowners, DIYers, agricultural operators or anyone who needs to dig.
When you submit a request, 811 notifies the utility companies where you plan to dig and issues you a ticket. Those operators then mark their underground lines at the site.
The Five Basic Steps
The USA North 811 California field guide lays out steps for a safe excavation. In short form, they look like this.
- Outline the planned excavation with white marks.
- Contact 811 at least 2 working days before digging, not counting the day you notify.
- Wait for every utility operator to respond.
- Respect the marks and dig carefully near them.
- Tell the utility right away about any harm to a line.
Tickets can be submitted through the mobile app, online or by calling 811. If a known utility is missing from your ticket, the guide says to call that utility directly.
Marking the Dig Area in White
Pre-marks show locators the planned work area. The field guide says California Government Code 4216.2(a) requires excavators to pre-mark the entire work area in white.
White paint, flags, stakes, whiskers or a combination can mark the area. Your white pre-marks, the mapping and the work description on your ticket should all match, which helps locators find the right place.
Outline only the area you will actually dig. A tight, clear outline helps locators focus on the right spot.
Waiting for Responses
Operators must respond before the legal start date and time on your ticket, according to the field guide. They post their responses through a system called Electronic Positive Response, and you can check those responses online.
Digging can begin once all operators have responded and any required on site meeting has taken place. The guide says work within 10 feet of a high priority line requires an on site meeting with the utility operator.
Response codes tell you what each operator did. Some show that a line was marked, some show no conflict and some ask for more time or a meeting.
The field guide lists a code for an operator that did not respond by the required time. A code like that means a response is still missing, so check with 811 about next steps instead of starting work. Reading every response before the first shovel goes in keeps the whole crew on the same page.
Reading the Colored Marks
Utility operators use the APWA uniform color code to show what type of line sits below, the field guide explains. Each mark carries its own identifying information, such as the company and line type.
Two examples from the guide help. Yellow marks a gas line, and purple marks reclaimed water. Sites with no line from a given company are often marked “NO” followed by the company identifier in that utility’s color.
Take photos of the marks once they appear. Photos help if rain, foot traffic or mowing fades them.
Digging Near the Marks
Marks show an approximate location, not an exact depth or edge. Hand tools are the rule close to lines. The guide calls for them within 24 inches of underground lines until you completely expose the line.
Marks can fade during a long job. If they do, the guide advises asking 811 for new markings and stop digging where the marks have faded.
Tickets do not last forever. The field guide says tickets are good for 28 days and should stay active until the excavation is complete. You can renew a ticket online or by dialing 811.
Private Lines Are Not Marked
This catches many homeowners off guard. USA North 811 says private utility lines will not be marked because they are not owned by a utility. Examples it lists include landscape irrigation and lighting, a gas line to a barbecue and an electric line to a detached garage or shed.
Gather what you know about private lines before digging. Old plans, permits and photos from past projects can help.
Planning ahead for future lines helps too. See what to decide before pavers cover utility lines.
If a Line Is Damaged
Accidents can still happen. The field guide says to report any damage to the utility company as soon as possible.
Specific ticket notices exist for these moments. A Damage notice applies when an excavator discovers or causes damage to a buried installation. An Exposed notice applies when a line is uncovered without harm.
Using the right notice keeps a record tied to your ticket. Keep the ticket number handy during the whole job so that any call to 811 goes faster.
When to Call 811 Before Digging
Build 811 time into the schedule. Two working days of notice, plus any meeting, should come first. Ticket types also matter. The guide says a Normal ticket covers digging that starts 2 working days to 14 calendar days after submission.
Common yard tasks that call for a ticket include planting trees and large shrubs, setting fence or pergola posts, trenching for irrigation or lighting and excavating for patios or walkways. Plan to call 811 before digging on any of these, even when the hole seems small.
- Pre-mark in white and match the ticket description.
- Keep the ticket number with the project notes.
- Photograph marks as soon as they appear.
- Hand dig within 24 inches of marked lines.
- Track private lines separately, since 811 will not mark them.
- Renew the ticket if the job runs past 28 days.
Large projects benefit from early planning. Read preparing a yard before major landscaping and which yard changes need a site survey for related steps.
Every yard is different. Taking a few days to call 811 before digging is a small step compared with the cost of a damaged line. More guides sit in the site preparation category.