Zoning in on Sewer Separation
Shawn Burke (Englobe Corp.)

The City of Saint John is embarking on a program of sewer separation in the Central Peninsula uptown area of the City, representing a very significant planned expenditure in the next 10+ year period.

To prioritize the +/- $200M in improvement projects identified, the project team developed an objective rating scheme and sequencing to implement the plan.

The Central Peninsula area was divided into ’“Zones’” based on the corresponding sewersheds, with all projects in a given zone required to separate the sewer systems in that area completely. The projects within each zone were assigned a priority score considering various criteria to represent the relative benefit of projects within that zone. Criteria included:

- Total Estimated Cost all projects in the Zone

- Resolves Current Capacity Issues: Quantify the number of properties with current hydraulic risks, which would be resolved through the separation program.

- Pipe Condition: % of pipes within the zone which have a poor condition rating as assigned by CCTV

- Flow Reduction: represented by the number of catch basin inlets which would be disconnected from the sanitary sewer from projects in the zone

- Project Cost / Catch Basins Removed: represents the cost/benefit relationship for the zone

- Supports Future Development?: One of the drivers of the sewer separation program is to free up sewer capacity for future development. This criterion quantified the number of development prospects according to the City within the zone.

By developing a repeatable, objective rating scheme, the City will be better equipped to prioritize investments that may be identified through future sewer separation studies, allowing them to compare ’“apples to apples’” across projects. This presentation will summarize the prioritization scheme and the information sources for each rating criteria employed on this project.