A SUE investigation was completed as part of the design phase of a major streetscape/water main/sewer project in downtown Hamilton, Ontario, Canada.
The project involved the installation, reconstruction, and replacement of municipal utilities in the area, and a major streetscape to improve the overall aesthetics of the downtown area.
The study included the collection of utility records, which were used as a basis for more than 10,000-ft. of utility designating (QL-B), conducted using electromagnetic cable located equipment.
The work also included 25 test holes (QL-A) for confirming the exact depth and size of pipes in critical locations.
The information derived from the study was used to support the design of the utility alignments. The data from the SUE study identified several conflicts due to erroneous or missing records.
Specifically, a large unmarked underground hydro tunnel was found to cross the proposed alignment of the new water main.
Other identified unmarked utilities that would have caused construction delays and cost increase included abandon gas mains and a phone duck structure.
In addition, exact location and characterization information were provided for other utilities for which records were incomplete.
A subsequent study conducted by the University of Toronto suggested that the City of Hamilton saved approximately $282,000 due to the SUE investigation, yielding a benefit/cost ratio of 6.6.
The cost of the SUE investigation ($42,785) amounted to approximately 1% of the total project cost.
Keywords: Downtown areas/suburbs; Benefit/cost; Cost, direct; Savings; EM (Electromagnetic) induction; Excavating; Pipe/cable locators (EM); Incomplete (utilities not in records); Inaccurate (wrong location/depth of shown utilities); Test holes (QL-A); Surface geophysical techniques (QL-B)