What 811 is and how the process works
811 is the national number for reaching the one-call notification system associated with the excavation location. The center collects information about the planned work and notifies participating operators whose underground facilities may be affected. The operators then provide the response required by the applicable law and ticket process, such as marks, instructions, or a positive response.
The excavator remains responsible for following the applicable notice period, ticket instructions, tolerance-zone rules, safe-excavation practices, and renewal requirements. Use the official state one-call directory for the project location rather than relying on a generic national timeline.
What 811 marks—and what may remain
The one-call center usually does not perform the field locate itself. It routes the ticket to participating facility operators. Each operator determines whether its facilities may be affected and responds within the framework that applies to that ticket. Marks therefore reflect the responding operator's facility information and responsibility, not a complete subsurface survey of every line on the property.
Customer-installed, privately operated, campus, parking-lot, irrigation, process, lighting, secondary, or other site utilities may fall outside an operator's response. That does not mean every line past a meter is private or that 811 never marks it. Confirm the actual ownership and response boundary for each system.
Public and private underground utility ownership
In this context, “public” and “private” describe who owns, operates, or is responsible for a particular underground facility—not whether the utility company itself is publicly or privately owned. Responsibility can change at a meter, service point, valve, transformer, demarcation, easement, building connection, or another defined location, but the relevant documents and operator should establish that boundary.
For examples and a practical ownership workflow, read What are private utilities? before assuming a line belongs to the utility or property owner.
How coverage questions differ by utility type
Ask the one-call center and each responding operator what its ticket covers at the specific property. The examples below are common questions, not nationwide ownership rules.
Water
An operator may mark facilities it owns or operates while private distribution, fire service, irrigation, or other site piping may require a separate water-line locate.
Sewer
Public mains, service laterals, private laterals, campus sewers, and site drains can have different ownership and access arrangements. Camera-sonde work may be needed for accessible private piping.
Gas
Operator-owned mains and service facilities may be part of the ticket response, while customer piping or private distribution can require separate investigation. Treat gas work as safety-critical and follow operator instructions.
Electric
Utility distribution and service facilities may differ from customer-owned feeders, site lighting, secondary circuits, generators, or campus distribution. De-energization and electrical safety are separate from locating.
Communications
Carrier facilities may be distinguished from private fiber, security, controls, inter-building communications, or customer-installed conduit. Multiple carriers and abandoned routes can complicate the site.
Irrigation and sprinklers
Landscape irrigation and sprinkler laterals are commonly property systems, but ownership and marking arrangements should still be verified. Small nonmetallic lines can be difficult to locate without records or tracer wire.
Does 811 mark water and sewer lines?
811 may trigger responses for participating water and sewer operators, but the response depends on the operator's facilities, the ticket, and local requirements. It is not safe to convert that into a nationwide yes-or-no rule for every service line or lateral.
If a water facility remains outside the response, review water line locating services. For accessible laterals or site drains, review sewer line locator services and the camera-sonde access requirements, or work through how to locate a sewer line underground before assuming the lateral runs straight to the street.
What to do when markings seem incomplete
Do not guess, extend a painted line, or begin excavation simply because one utility color is absent. Check ticket status and responses, confirm that the proposed excavation area was described correctly, follow the one-call center's instructions for missing or disputed responses, and contact the relevant operator when directed.
Review every response
A no-conflict or completed status can carry different information from visible paint. Read the ticket and operator notes.
Verify the work area
Confirm that white lining, address, access, excavation limits, timing, and contact details match the planned work.
Resolve missing responses
Use the state center's escalation or re-notification process and wait as required before disturbing the site.
Investigate private facilities
Compile plans, owner knowledge, visible appurtenances, and a private locating scope for facilities outside the operator response.
When to hire a private utility locator
Consider a private locator when project records or site evidence indicate customer-owned utilities, when operator responses identify exclusions, when the work is on a campus or complex property, or when unexplained appurtenances and gaps remain after the required one-call process. The proposal should name the search area, target systems, methods, access, deliverables, and limitations.
Private locating supplements rather than replaces required one-call notification. Critical crossings or design decisions may also need mapping, engineering, or physical verification beyond ordinary field marks.
Unlike the one-call response, a private locate is a paid professional scope. Review what private utility locating costs to understand published rate examples, the variables that drive a quote, and what to confirm before hiring, and how underground utilities are located for the methods and equipment a proposal should name. For the role itself, see what a utility locator is.
Common questions
Frequently asked questions
Does 811 stop marking at the meter?
Not as a universal rule. A meter can be an ownership or service point for some systems, but the boundary varies by utility, facility, agreement, property, and jurisdiction. Confirm the responding operator's actual scope.
Does 811 locate private lines?
The one-call process notifies participating operators to respond for facilities within their responsibility. Privately owned or operated site utilities outside those responses generally require separate owner action or a private locator.
Does an all-clear mean no underground utilities exist?
No. It ordinarily communicates the responding operator's status for the ticket. Other operators, private facilities, abandoned lines, or unknown features may still exist. Read every response and investigate unresolved evidence.
Where can I find the official 811 rules for my project?
Use the state one-call center directory and follow that center's official ticket instructions, laws, timing, renewal, and escalation information.