Ground Disturbance Permit Support
The permitting process and Safe Work Permit are the first steps of safe work practices, whether the job site is in a chemical facility, refinery, or a commercial area. Every work permit starts with a Job Safety and Hazard Assessment, especially a ground disturbance or excavation permit.
Prior to an excavation, the ground should and must be assessed for unknown utilities or buried obstructions that could pose hazards to the work process. This is part of the due diligence that every permit writer or area owner should require from contractors or plant employees in order to issue a Safe Work Permit for the job site, thus allowing work to begin.
One of the most effective ways to support Safe Work Practices is to perform a comprehensive Subsurface Utility Investigation on Quality Level B (also known as QLB) and then follow it up with a Quality Level A investigation.
Applied Geophysical methods are suitable for conducting QLB investigations. They are part of the noninvasive investigations that are ideal for mapping out unknown underground utilities and/or obstructions, whether they are vertical or linear.
The following example illustrates a utility mapping process at QLB:
The first image shows the actual work site.
Images #2 and #3 display the results of scanning and locating.
Image #4 is a GIS map transformed into an appropriate NAD83 (North American Datum Easting and Northing coordinate) Zone, with located target accuracy of 3-5 cm (1 ½-2 inches).
As a result of a comprehensive Subsurface Utility Investigation, all locatable known and unknown utilities are mapped out in a transferable and portable file format for further use in planning.
Actual work site.
Trenching
Result of GPR and Locate
GIS map transformed into an appropriate NAD83 (North American Datum Easting and Northing coordinate) Zone
