Feature Project: Duffin Creek WPCP Stages 1&2 IPS &Headworks

Monday, 08 May 2017

The Duffin Creek Water Pollution Control Plant (WPCP) is a critical component of the York Durham Sewage System. Jointly owned by The Regional Municipalities of York and Durham, this plant serves the water pollution treatment needs of Aurora, Newmarket, Vaughan, Richmond Hill, Markham, Pickering, and Ajax. This plant currently has the capacity to treat an average of 630 ML/day.

To meet the growing needs of both regions, the plant has undergone significant expansion over the years. The scope of this contract requires construction of an influent pumping station, preliminary treatment building, flow metering building, and electrical building. The work also includes a biofilter odour control system, phosphorus removal system, flow control chambers, channels, as well as site services, duct banks, aerated grit tanks, electrical system, instrumentation and controls, and other mechanical and process systems.

The cast-in-place concrete work involved a total of 32,000 m2 of formwork and 17,000 m3 of concrete. Kenaidan self-performed the concrete package in addition to the building and process mechanical installation works.


To date, approximately 99% of all concrete work has been completed for both the Influent Pump Station (IPS) and the Preliminary Treatment Building (PTB), with only two stairs, toppings, grouting, and some rub-up work still remaining. The majority of the site has also been backfilled to grade with most of the curb and asphalt paving completed.

Exterior architectural items including roofing, windows, doors and frames, and overhead doors have been installed. The IPS and PTB buildings are now closed in with painting and interior finishes well underway.

Landscaping activities were completed late spring. All major equipment has been delivered to the site including the owner-supplied raw sewage pumps. Installation of major mechanical and electrical systems are nearing completion. Commissioning activities are underway and 10-day wet testing took place in early April. This kicked off substantial performance for the project.

Construction began in June 2014 and is scheduled to be substantially complete in late May or early June 2017.

This project is part of the ongoing expansion of the existing plant where Kenaidan recently completed the Stage 3 Influent Pumping Station and Stage 3 Dewatering and Incineration facilities.

Contract Services: Stipulated Lump Sum

Concrete: 17,000 m3

Formwork: 32,000 m2

Design Features:

  • Temporary secant shoring systems
  • A 22 m diametre by 30 m deep influent pump station with two interconnected wet wells, equipped with eight submersible pumps, each rated at a capacity of 2,093 L/s
  • Preliminary treatment, complete with screening system, grit removal, aerated tanks, and displacement blowers
  • Biofilter odour control system rated 19.7 m3/s
  • Phosphorus removal system, complete with chemical tanks and dosing equipment

Key Challenges:      

  • Coordination of owner-supplied equipment deliveries and commissioning
  • Construction scheduling and methodologies for effective tie-ins to the existing plant with minimal interruption to daily operations
  • Complex resource-loaded project scheduling
  • Secant shoring and deep excavation into rock at the influent pump station
  • Coordination with other adjacent active contracts and contractors