Page 11 - CCGA Best Practices Version English

During the detailed design phase of a project, it is necessary to develop
detailed information on the locations of utility facilities in the project area in
order to ensure accuracy, and minimize the possibility of utility conflicts.
This detailed information can be obtained through a survey of utility
infrastructure and the methods utilized should be documented.

Benefits: Gathering underground facility information and incorporating this
information in the planning and design phase minimizes the hazards, cost,
and work to produce the final project. Safety is enhanced, unexpected facility
conflicts are eliminated, and facility relocations are minimized.
Current Practice:
Project owners utilize some basic practices when performing a survey of
utility infrastructure. For effective results the steps should be performed in
sequence. However it is not necessary to complete all steps depending on
the level of information required. The steps are as follows:
1. Use all available existing utility facility records to obtain information about
locations of existing and proposed underground facilities in the entire
construction project area;

2. Visit the job site to correlate the information already gathered about
existing utility facilities with above ground features;

3. Use appropriate instruments to determine the approximate horizontal
locations of the underground facilities identified; and

4. Use test holes to positively determine the exact location of existing
underground facilities. At this point, horizontal and vertical control
measurements may be taken. Test holes are used to positively locate
and identify an underground facility by exposing the facility by a
nondestructive means, e.g. vacuum excavation.

References:
• CSA S250-11, Mapping of Underground Utility Infrastructure

1-5: Subsurface Utility Engineering (SUE)

Practice Statement: The project owner should consider the use of
Subsurface Utility Engineering (SUE) techniques as a structured method of
gathering and depicting utility information for design purposes.
Practice Description: SUE is applied during the design phase to locate,
identify, and characterize all existing utility infrastructure (and other
relevant non-utility features) found within a given project. SUE is applied
in a structured manner, in accordance with practices and Quality Levels
found in ASCE 38-02 Standard Guideline for the Collection and Depiction of
Existing Subsurface Utility Data. Although the Standard is more detailed and
comprehensive, the following is a brief summary of the Quality Levels defined
therein: Quality Level D – information gathered solely from existing utility

Canadian Common Ground Alliance
Best Practices Version 3.0 – October 2018
8