What 811 Does and Does Not Locate
811 marks utility-owned lines. Private lines — like your water service lateral or sewer lateral — may not be marked.
Tennessee 811 marks the approximate location of underground utility-owned lines — typically water, sewer, gas, electric, and communications lines that are owned and maintained by utility companies. 811 does not mark private lines — lines that were installed by a homeowner or a previous property owner and are not owned by a utility. This includes private water service lines (from the meter to the house), private sewer laterals (from the house to the main), irrigation systems, landscape lighting wiring, and any other customer-owned underground lines. If you need private lines located, you may need to hire a private locating service.
Why This Matters
Assuming that 811 marks every buried line on your property is a common and dangerous mistake. If you dig based on 811 markings alone, you may hit a private line — your own water service, a sewer lateral, or an irrigation line — that was never marked because it is not utility-owned. Understanding what 811 covers and what it does not helps you plan excavation safely and avoid damaging your own infrastructure.
How It Generally Works in the Knoxville Area
What 811 typically marks (utility-owned lines): • Water mains and utility-owned service lines (typically from the main to the meter) • Sewer mains (but typically not the private lateral from the house to the main) • Gas lines owned by the utility • Underground electric lines owned by the utility • Communications lines (telephone, cable, fiber) owned by the provider What 811 typically does NOT mark (private lines): • Private water service lines (from the meter to the house — the homeowner-owned portion) • Private sewer laterals (from the house to the sewer main) • Irrigation systems • Landscape lighting wiring • Electric lines installed by a homeowner or previous owner (not connected to the utility meter) • Propane or fuel lines installed on private property • Any line installed by a private party that is not owned by a utility If your excavation project is near any of these private lines, you may need to hire a private locating service. A plumber can also help identify the location of private water and sewer lines using pipe tracing equipment.
What 811 Marks vs. What It Does Not
811 Typically Marks
- • Utility-owned water mains and service lines (to the meter)
- • Utility-owned sewer mains
- • Gas lines owned by the utility
- • Underground electric lines owned by the utility
- • Communications lines (telephone, cable, fiber)
811 Does NOT Mark
- • Private water service lines (meter to house)
- • Private sewer laterals (house to main)
- • Irrigation systems
- • Landscape lighting wiring
- • Private propane or fuel lines
Private lines may require a separate private locating service. A plumber can help trace private water and sewer lines.
What the Homeowner Can Check
- Whether there are private lines on your property that 811 will not mark
- Whether your project is near a private water service line or sewer lateral
- Whether you need a private locator in addition to the 811 locate
- Whether the 811 markings are still visible and have not faded
Who to Contact
A Licensed Plumber
A plumber can help trace and locate private water and sewer lines using specialized equipment.
Learn moreA Private Locating Service
If you need private lines (irrigation, landscape lighting, private fuel lines) located, a private locator can help.
What Not to Do
- Do not assume 811 marks all buried lines on your property — private lines are not included
- Do not dig near a private water line or sewer lateral without knowing its location
- Do not rely solely on 811 markings if you know there are private lines in the area
Still not sure who is responsible or what to do next?
Ask our AI Plumber — describe the problem and get guidance on whether it is likely on your side or the utility side.
Ask the AI PlumberVerify current requirements directly with the applicable authority.
Requirements may differ depending on whether the property is inside the City of Knoxville, elsewhere in Knox County, or served by another utility. Homeowners should verify current requirements with the applicable permitting authority before beginning work.
Common Questions
Will 811 mark my sewer lateral?
Generally, no. The sewer lateral — the pipe from your house to the sewer main — is typically private and is not marked through the standard 811 process. A plumber can help trace it using pipe location equipment.
Will 811 mark my water service line?
811 typically marks the utility-owned portion (from the main to the meter). The homeowner-owned portion (from the meter to the house) is private and is not marked through 811. A plumber can help locate it.
How do I find a private locator?
Private locating services can be found through online directories or by asking a plumber for a referral. A plumber who does water line or sewer line work often has pipe tracing equipment and can locate private lines as part of the project.
If the problem involves your home's plumbing, The Classic Plumber can help.
We diagnose before we recommend — and we tell you when the issue is on the utility's side.