Frequently Asked Questions

Utility Locates & Concrete Scanning


It’s the law. Occupational Health and Safety Act Section 228 – Precautions regarding underground services: “Before an excavation is begun; gas, electrical and other services in and near the area to be excavated shall be accurately located and marked” ”The employer responsible for the excavation shall request the owner of the service to locate and mark the service”

A locate is the name given to the detection, marking, and reporting of buried utility services on a job site. Utility lines are detected using various technologies by scanning the ground above the location of the lines.

The detected utility is then marked on the surface of the ground using temporary marking paint, stakes or flags to indicate the horizontal position of the line.

A report is created showing the location of the utilities in relation to adjacent structures and features. It may be applied to both public and private.

By just calling 1-call you are not covered. You may have only notified Bell and Gas. There may be 3 to I 0 + other utilities that may need to be notified.

Even if you notified all of the other utilities you may have private utilities to be located.

USL-1 will notify all known utilities in your work zone. complete the private utilities and supply you with a package with all of your public and private locates.

We use Radio Detection receivers and transmitters to locate utilities that can carry an electrical signal (conductive material).

Sondes – a special transmitter that can be inserted into a pipe I conduit that non-conductive. i.e., a PVC pipe.

Ground Penetrating Radar (GPR) imaging equipment is used to detect utilities and storage tanks (USTs).

Public utilities are the utilities owned by the utility companies and can be located on Public AND private property.

  • Public utilities are the mass distribution network of the utilities and the main feeds to properties. They become private at the demarcation point (i.e. – meter, transformer, vault) that may reside on private property. The utility owners are responsible for the locates. Examples: Bell, Rogers. Hydro Ottawa ….
  • Private utilities are the utilities owned by an individual or company on private property. It can be any utility on a site beyond the public utilities. The utility owners are responsible for the locates. Examples: parking lot lights, hydro distribution to out buildings, security cameras. communication line ,etc.

When we are asked to provide a full locate service including co-ordinating the public utilities and locating the private utilities please allow for 5 full business days with the I st day being counted as the day following the request.

This is the industry standard for locates for the public utilities. Please note that at peak times they may be delayed.

Almost all locates, Public and Private expire after 30 days. If marks disappear (for any reason) you must obtain a new locate. You must not work outside of the area indicated as the work zone on the locate report .

The nature of the work as described in the locate must cover the work being done. Failure to follow these guidelines will expose you to greater risk of liability for damages.


Slab, suspended, on grade, on pan, wall, ceiling and beams.

Rebar, post tension cables, conduits and voids.

For core drilling, concrete testing, saw cuts, trenching and anchoring.

We employ the latest technology including Ground Penetrating Radar (GPR) and Radio Detection.

GPR is imaging equipment that visually sees changes in materials.

Radio Detection receivers and transmitters and used to trace out embedded conduits by inducing a signal onto a conductive line and locating it with the receiver.