MUNICIPAL > Distribution & Collection Systems
400mm Sanitary Relief Sewer on Weldrick Road
Client: Town of Richmond Hill/York Region
Location: Richmond Hill
Construction Value: $1,700,000
Services: Preliminary Design Report, Detailed Design, Contract Administration and Resident Site Inspection, Post-Construction Services
Key Features
- 1.3 km of 400mm sanitary relief sewer on Weldrick Road from east of Bathurst Street to east of Yonge Street.
- 100m crossing of Yonge Street using ‘Jack and bore’ tunneling (1200mm steel casing).
- Traffic management and construction staging strategies were utilized to minimize traffic disruption.
- Subsurface Utility Engineering (SUE) – non-disruptive test pits – were employed to eliminate utility conflicts during construction.
Delays in the construction of Regional trunk sewers resulted in concerns that a section of the primary Regional trunk sewer (the “Richmond Hill Collector”) could be subject to surcharging under wet weather events.
An investigation of opportunities identified Weldrick Road as the preferred route for constructing a relief sewer to convey excess flow to the nearby North Don Collector sewer, with urgency in completing the work to avoid potential sewage overflow and/or basement flooding.
A hydraulic analysis determined the new relief sewer size so as to not exceed the maximum allowable rate for flow diversion and downstream capacity.
A successful Subsurface Utility Engineering program with 36 non-destructive test pits was employed to eliminate utility conflicts during construction. An 800m length of existing gas main was relocated in the process.
Extensive liaison with stakeholder groups and regulatory agencies were required for permits and approvals comprising TRCA for a culvert crossing, MOE for dewatering, and utility companies for utility relocations and crossings.