case study: network-wide inspection and assessment
City of Toronto, Ontario
The City of Toronto owns and operates an extensive trunk sewer network, comprising 350,000 m of large diameter sewers and 3,000 maintenance holes. The sewers, grouped in 110 ‘named’ trunks, service an area of 630 km2 with a population of 2.7 million people. Andrews.engineer was retained by the City over a 4-year period to inspect and assess the condition of the entire trunk network and to compile a comprehensive condition assessment database and rehabilitation strategy. The assignment included CCTV and Sonar inspection of the sewers, inspection of MH’s and evaluation of 250 CSO chambers. Focused investigations including structural analysis at key sites and laser profiling of segments with critical depths of H2S corrosion were also undertaken.
As part of the assignment, A.E developed, tested and implemented a comprehensive database which was linked the existing network geodatabase (ArcInfo©). Tables were created and populated to document inspection observations, condition assessment results and rehabilitation recommendations. Data was compiled for both the sewers and MH’s. To ensure accurate and consistent information, A.E established the following guidelines, validation rules and management controls:
- Robust quality control procedures
- Efficient data control throughout the collection and reporting process
- Ease of use and understanding of the added fields
- Flexibility to meet requirements of multiple users
- Proper data safeguards and storage
The in-house database enabled users to review and analyze the inspection data and reference videos easily. Related data such as laser profiling and sonar imagery were also linked in the database. After full QA/QC review, the collected data was joined to the City’s geodatabase including updated geospatial information. Toward completion of the project, the City of Toronto adopted InfoNet as their standard asset management platform. A.E worked with the City to migrate the geodatabase structure into the InfoNet structure.
|date:||2008 to 2012|
Trunk sewer and MH inspection
Confined space entry programming
Hydraulic performance evaluation
Hydrogen sulphide monitoring
Rehabilitation planning & programming