The short version: 811 notifies the utility companies that are members of Colorado 811, and they mark the lines they own — usually up to the meter. Lines past the meter that belong to the property owner aren't theirs to mark. A private utility locator finds those.
| Colorado 811 | Private locate | |
|---|---|---|
| Who marks | Each member utility marks its own lines | A private locating company you hire |
| What gets marked | Lines owned by member utilities, typically up to the meter | Privately owned lines in the area you need located |
| Cost to you | No charge | Paid service, quoted by site and scope |
| Required before digging? | Yes, under Colorado law | Not by name — but often the only way to find private lines |
What happens when you call 811
Colorado 811 is the state's one-call notification center. When you submit a locate request, it notifies the member utility owners and operators with facilities near your dig site. Each one is responsible for marking its own lines — gas, electric, telecom, water and sewer, depending on who has facilities in the area. Excavators in Colorado are required to contact 811 before digging.
What 811 typically doesn't mark
Utility companies mark what they own. Once a line passes the meter or the point where ownership changes, it usually belongs to the property owner — and nobody on the 811 side is responsible for marking it. Common examples:
- Gas lines from the meter to the house, a shop, a pool heater or a fire pit
- Propane lines from a tank to the buildings it serves
- Electric lines from the meter or panel to detached garages, shops, barns, gates and well pumps
- Parking lot lights, sign lighting and other site lighting on commercial properties
- Private lines between buildings on apartment complexes, campuses and commercial sites
- Irrigation lines and control wiring
- Private water and sewer service lines — where ownership changes varies by provider, so check with yours
Exactly where ownership changes depends on the utility and the property. A good rule of thumb: assume anything past the meter is private until you know otherwise.
When you need a private locate
- The property has outbuildings, detached garages, shops or barns with power or gas
- You're working on a commercial, multi-building or campus-style site
- The site has parking lot or exterior lighting
- The property uses propane
- You're digging anywhere between the meter and a building
- The owner doesn't know what's been installed over the years
- You're boring, trenching or setting footings where a strike would be costly
Not sure? Call (720) 514-2876 and describe the site — we'll tell you whether a private locate makes sense.
How a private locate works
A private locator uses electromagnetic (EM) equipment to trace lines that can carry a signal — metallic pipe, electric and communication cable, and plastic pipe with tracer wire. Lines are marked on the surface in standard APWA utility colors. At Mile High Locating, we also walk you through what we found and anything we couldn't trace, and we can provide a written locate report on request.
EM locating has limits. Plastic or clay pipe without tracer wire, and lines with a break in the conductor, may not be detectable. A good locator will tell you when that's the case rather than guess. More on what we locate.
811 and a private locate work together
A private locate doesn't replace your 811 ticket. Call 811 for the member utilities, and bring in a private locator for everything past the meter. Between the two, you'll have the clearest picture of what's in the ground before you dig. If you're a contractor, here's how we work with crews.
This guide is general information, not legal advice. For your obligations as an excavator, see Colorado 811 and C.R.S. Title 9, Article 1.5. Mile High Locating is a private locating company and is not affiliated with Colorado 811.