What Is 811 Utility Locate Service (Dig Safety Rules)

811 is a free notification service that helps prevent damage to buried utilities before excavation. Submit a locate request, wait for the required responses, and check that marks cover your work area. Then follow local safe-dig rules. 811 does not locate every private line, show exact depth, or give permission to dig without caution.

A shovel, fence post, garden bed, or small trench can reach a buried gas, electric, water, sewer, or communications line. Striking one can cause injury, service outages, costly repairs, or a dangerous leak. Calling 811 before ground disturbance is a key first step, but the call alone does not make digging safe.

I explain the process as a series of checks, not a single phone call: request a locate, confirm the responses, understand the marks, and dig carefully around them. The exact rules depend on where you live, so use the local 811 center and laws for your project.

What 811 Utility Locate Service Does

811 is a notification service that connects your planned excavation with participating utility operators. Those operators, or their locating contractors, identify and mark the underground facilities they own or maintain near your work. The service helps you find possible conflicts before digging, but it does not mark every buried line or certify the exact location of each facility.

When you contact 811, you provide the work location, planned date, type of work, and other details the center requests. The center sends the notice to member utility operators with facilities in the area. Operators then respond by marking their lines, reporting that they have no facilities there, or giving another status recognized by the local system.

The marks show the approximate path of a facility, not a guarantee of its depth or exact position. They also do not mean you can dig anywhere around them without following local rules. Check your ticket and the 811 center’s instructions for response deadlines, status terms, and what to do if a response is missing.

What 811 may not locate

811 usually covers facilities that participating operators own or maintain. Customer-owned lines may fall outside their responsibility. Examples can include private electrical wiring, irrigation pipes, propane lines, sewer laterals, and communications cables beyond an operator’s service point. Coverage depends on the facility and location.

If you are unsure who owns a line, ask the utility or 811 center. Arrange a qualified private utility locate for lines that are not covered. Do not assume that an unmarked area is free of buried utilities.

811 Ticket, Site Preparation & Crew Safety

An 811 ticket is a locate request tied to a stated work area, activity, and time period. Before excavation, define the full area where soil will be disturbed, submit an accurate request, and confirm what responses are required. Local rules set the notice period and ticket life, so there is no single nationwide waiting time or validity period.

1. Plan the request

Include the whole work zone, not just the spot where a tool first enters the ground. The work may include digging, trenching, grading, boring, planting, or stump removal. Describe the method and location as clearly as the local center requires.

Some centers ask you to mark the proposed dig area in white paint or flags before the locate request. This is called white-lining. It helps operators see the area you plan to disturb. Follow local instructions on whether it is required or recommended.

Submit the request at least the locally required number of business days before work. Do not treat the waiting period as permission to start. Wait until the required response time has passed and required operator responses are complete.

2. Check responses before work

Before anyone digs, confirm that the ticket is active and covers the planned work. Review each operator’s response and make sure marks are visible and understandable. If an operator has not responded, a mark is missing, or the status is unclear, contact the 811 center or operator and resolve it first.

The comparison is simple: a complete ticket is a starting point; an unresolved response is a reason to pause. Never dig solely because no marks are visible.

Mark Verification & Safe Excavation in the Field

Utility marks help show the approximate route of underground facilities, while a tolerance zone sets a legally defined area around a marked facility. The zone’s width and safe-dig methods vary by jurisdiction. Check local rules and the ticket, then use the required care near each marked line rather than relying on a universal distance.

Read and protect the marks

Utility color codes are commonly used to distinguish types of facilities, but confirm the code used in your area. Marks can be paint, flags, or other approved indicators. Make sure the crew understands which marks relate to the planned excavation and keep the marks visible during the work.

If rain, traffic, landscaping, or other work removes or obscures marks, stop in the affected area and contact the operator or 811 center about remarking. A faded mark is not a reason to guess. Do not move or remove marks unless the operator or local rules allow it.

Work carefully near a marked facility

A tolerance zone is the area around a marked utility where extra care is required. Its legal width is not the same everywhere. Find the applicable distance and excavation method on the ticket or from the local 811 center. Within that zone, expose the facility using methods permitted by local law, and maintain any required clearance.

As excavation approaches a marked line, use the required safe method to determine its actual location. Do not assume marks show exact depth. Once exposed, protect the facility and avoid striking, pulling, or undermining it. If the line is not where expected, stop and seek guidance before continuing.

For construction excavations covered by OSHA rules, 29 CFR 1926.651(b) requires estimating utility locations before excavation, contacting utility owners, determining exact locations by safe means as excavation approaches, and protecting utilities during the work. Check whether those rules apply to your project and follow any stricter local requirements.

Two common field scenarios

These examples are practical scenarios, not reports of specific projects. They show why a locate ticket must be checked against the conditions on site.

• Planting a tree near marked lines: The ticket shows utilities near the planting area. The owner checks the local tolerance-zone rule before digging. If the proposed hole falls within that zone, the owner follows the locally required method to expose the facility and changes the planting location if needed.
• Trenching where a mark has disappeared: A crew returns after weather has faded a mark. Rather than estimating the route from an old photo, the crew pauses and requests clarification or remarking. Work resumes only when the marks and responses are clear.

Locate Records, Changes & Re-Notification

A locate ticket applies only to the location, work, and validity period stated in the request. Keep the ticket details and response records available while work is underway. If the ticket expires, the work area or method changes, or marks become unclear, contact 811 to learn whether you need a revision, refresh, or new request.

Record the ticket number, request date, planned work, operator responses, and any follow-up with the 811 center or utilities. Photos of marks and site conditions can help document what was present, but they do not replace required marks or a valid ticket.

Re-notification may be needed when work continues past the ticket’s allowed period or moves beyond the described area. Do not assume a previous request covers a later project simply because the same property is involved. Ask the local center which request applies.

A crew briefing should cover the ticket area, utility marks, tolerance-zone rules, the required excavation method, and who will contact the operator if conditions change. This small check helps prevent different workers from making different assumptions about the same marks.

Utility Damage Response & Worksite Closeout

If you expose an unknown line, find a mismatch, or damage a utility, stop work and keep people away from the affected area. Notify the utility and 811 center. If there may be a gas leak or another immediate danger, move to a safe location and call emergency services and the utility without creating ignition sources nearby.

If a line is unmarked or mislocated

An 811 request does not guarantee that every facility will be marked, or that a mark gives its exact depth and position. If an unknown line appears, or a marked utility is not where expected:

• Stop excavation in the affected area.
• Keep people and equipment clear; do not touch or move the line.
• Contact the utility operator and 811 center for direction.
• Resume only after the issue is resolved and the safe method is clear.

If a utility is struck, treat it as a potential hazard even if damage seems minor. For suspected gas release, evacuate to a safe location. Do not operate equipment, use flames, or create sparks near the suspected release. Call emergency services and the gas utility from a safe place.

Close out safely

When work is complete, leave exposed facilities protected and the site safe. Keep records of the ticket, responses, and any field issue. Report damage or a near miss promptly through the appropriate utility and 811 channels. A completed project does not extend the ticket to future work beyond its scope or validity.

The key rule is to pause whenever the marks, responses, or actual conditions do not make sense. Ask before proceeding rather than guessing around a buried line.

Frequently Asked Questions

Is 811 free?
In many areas, homeowners and excavators can submit a locate request without a charge. Check the local 811 center for its rules and any service fees that may apply to additional work, such as a private locate.

How long before digging should I call 811?
It depends on state and local rules. Submit the request at least the required number of business days ahead, then wait until the required response period has passed and the necessary utility responses are complete.

Does 811 mark every buried line on my property?
No. The service notifies participating utility operators about facilities they own or maintain. Private lines, such as some irrigation, customer-owned electrical, or propane lines, may need a separate private locate.

Can I dig if no utility marks appear?
Not just because marks are absent. Check the ticket and operator responses, then contact 811 or the relevant utility to resolve missing marks or unclear status before digging.

Do 811 marks show how deep a utility is?
No. Marks indicate an approximate route at the surface, not a reliable depth. Follow local safe-dig rules and determine the facility’s exact location by the required method as excavation approaches.

What is a tolerance zone?
It is a legally defined area around a marked utility where extra care is required. The width and allowed excavation methods vary by jurisdiction, so check local requirements rather than relying on a general distance.

How long is an 811 ticket valid?
Ticket validity varies by location and request type. Check the ticket or ask the local 811 center. Renew or revise it if it expires, the work changes, or marks become unclear or disturbed.

What if my project changes after the locate is complete?
Contact the 811 center to check whether you need to update the ticket or submit a new one. A ticket only applies to its stated location, work, and validity period.

What should I do if I hit a utility line?
Stop work, keep people clear, and notify the utility and 811 center. If there is a suspected gas leak or immediate danger, evacuate and call emergency services and the utility from a safe location.

Do I need 811 for a small project, like planting or setting a fence post?
Ground disturbance can reach buried utilities even on a small project. Check local law and contact 811 before digging, planting, trenching, or removing a stump.

(This article was written by one of our staff writers, Evan Bradley. Visit our Meet the Team page.)