What we find after 811 has been out

Calling 811 is free, legally required, and the right first step on any excavation. It is also not a guarantee that everything in the ground has been marked.

Our technicians complete a field report on every job, and one of the questions on it is whether 811 was completed before work started. The examples below are drawn from those reports between May and September 2026. In each case the public locate had been requested, and we still found something that had not been marked.

From our own field reports

• May, Central Oregon: an 811 request was placed and no 811 marks were present in the area at all.

• May, Puget Sound: 811 completed, cable lines not marked.

• June, Portland: called back to locate additional missed public locates across the entire area.

• June, Puget Sound: secondary communications lines missed on the public locate.

• July, Puget Sound: a gas main in the roadway had not been marked. We recommended the client call the operator back out before work continued.

• July, Puget Sound: swept the work area with GPR for additional unmarked utilities and marked two further locations for the crew to check.

• September, Puget Sound: a partial 811 locate with many utilities missed.

• September, Puget Sound: partial marks with several areas of the site missed entirely.

Other reports in the same period recorded the public locate as covering only part of a site, with answers such as power only, power and gas only, and half completed of thirteen sites.

Why this happens

None of this means anyone acted improperly. 811 operators mark from their own records within their own standard of care, and the system depends on those records being complete and on every affected operator responding.

Marks get missed when a facility is not in an operator's records, when a line sits on an easement that was never properly documented, when an operator does not respond to the ticket, or when the marks are made and then disturbed by weather, traffic or equipment before the crew arrives.

What verification adds

Verifying the public marks is a distinct service from locating private utilities. On site it means checking what has been marked against what we detect, and marking public line that was missed.

For excavators the practical value is simple: the marks on the ground become something you have checked rather than something you have assumed. See also our case study of an unmarked medium voltage line found during an ALTA survey.

If a mark looks wrong before you dig

Contact the operator that owns the line. Marking concerns numbers by county: Oregon, Washington, North Idaho, Montana.

Private locating and public mark verification

Advanced Underground Utility Locating has been locating private utilities since 2002. We locate the lines 811 will not mark, verify the public marks that were made, and mark public lines that were missed.

Spokane, Coeur d'Alene and the Idaho panhandle: 509-710-2621. Seattle, Tacoma and Portland: 509-954-8623. Bend, Medford and northern California: 541-678-0629. Eugene and Roseburg: 541-780-4149. Coos Bay and the Oregon Coast: 541-315-6728.

Examples are taken from our own field reports and have been anonymised. No customers, sites or utility operators are identified.