Challenge

The water, sanitary, and storm water infrastructure renewal backlog is of growing concern to Canadian municipalities. The construction of these infrastructure assets has typically followed urban growth cycles. Even in a relatively young municipality such as Ft. Saskatchewan, older infrastructure installed from the middle of the previous century is at or approaching the end of its expected service life.

Solution

By using the recommended treatments coming out of dTIMS, Fort Saskatchewan is able to coordinate their infrastructure works programs. This project encompassed three phases:

1. Asset Inventory & Replacement - The primary source for data on the City's water mains, sanitary sewers, and storm sewers were the data stored in the City's ESRI ArcGIS. By averaging the install dates of the City's underground utilities, a map of the location distribution of pipes by their decade of installation was created. From this map, it was clear that development in certain areas within the city occurred approximately at the same time, and it was fair to assume that any future renewal or replacement of pipes would also occur approximately on a neighbourhood-by neighbourhood basis.

2. Determine Pipe Condition - A set of Weibull cumulative distributions were created in MS Excel® to depict a set of deterioration curves for pipes with different expected service lives (ESLs). The ESL is defined as the period of time over which the asset is actually available for use and able to provide the required level of service at an acceptable risk; for example, without unforeseen costs of disruption for maintenance and repair. The pipe ESLs were based on common practice at other municipalities, with some of the ESLs subsequently revised based on the experience of municipal staff at the City. The ESLs used for this assignment ranged from 50 years for concrete and vitrified clay tile sewers, 60 years for asbestos cement water mains, 80 years for all PVC mains, and 100 years for concrete storm mains.

3. Software Solution - dTIMS enabled optimized decision making and mathematical deterioration modelling of infrastructure assets and the development of short, medium, and long-term forecasts of pipe renewal and replacement costs.

Results

• Coordination of open-cut interventions between water mains, sanitary and drainage sewers, and roadways

• Elimination of “silo based” planning

• Annual savings of $85,000