Every community needs safe and reliable wastewater infrastructure. The Regional Municipality of York in Ontario, Canada, continuously works to improve its wastewater infrastructure to support the region’s growth and protect its water resources.
Part of the greater Toronto area, The Regional Municipality of York covers 1,776 square kilometers and has a population of about 1.1 million people. Along with the Regional Municipality of Durham, it owns the Duffin Creek Water Pollution Control Plant (WPCP), which is located on the shore of Lake Ontario in the city of Pickering, Ontario.
The WPCP facility receives and treats 90 percent of York’s wastewater as well as wastewater from Pickering and the town of Ajax in Durham Region. The WPCP is a major part of the York Durham Sewage System (YDSS), a centralized sewage treatment system that was first constructed in the 1970s.
The YDSS comes together at the WPCP to discharge treated wastewater into Lake Ontario.
An effort to expand and improve the WPCP has been ongoing for a number of years. In 2006, York and Durham Regions completed a Schedule C Municipal Class Environmental Assessment based on the requirements of the Ontario Environmental Assessment Act, in an effort to expand the WPCP’s capacity.
“York has been growing by about 25,000 people per year for the last 10 years, and projections show York Region and part of Durham growing to more than 1.5 million people by 2031,” says Euan Ferguson, York Region’s manager of engineering.
“The plant was projected to reach its capacity by 2011, so we needed to design and build an expansion to increase its capacity and deliver those projects on time and on budget prior to the end of 2010,” Ferguson adds.
The project was designed to improve the wastewater system’s treatment infrastructure. In addition, Ferguson explains, it was designed to enhance environmental protection efforts and increase the plant’s ability to handle commercial and residential growth.
The federal and provincial governments have contributed a total of $93.3 million to the project through the Building Canada Fund. Beyond that, both York and Durham Regions are providing the remaining funding toward this $625 million project.
Thus far, this funding partnership between the federal, provincial and municipal governments has upgraded the existing facility’s infrastructure. Some short-term solids capabilities were completed in 2009, and the larger solids capacity part of the project is ongoing.
The project also increased the WPCP’s wastewater treatment capacity from 420 million litres per day (ML/d) to 630 ML/d, commissioning the work in 2010 and expanding the capacity in 2012. In addition to expanding the plant’s capacity, the project also allowed the plant to remove higher levels of phosphorus and ammonia.
“During design, we felt we should look at increasing the level of treatment to provide a cleaner wastewater product,” Ferguson explains. “We came up with the idea of putting a biological nitrification and denitrifcation process in place.”
In addition, a new, state-of-the-art solids-handling facility has been constructed to prevent the need to truck biosolids to landfills.
Other parts of the expansion’s design include advanced energy recovery technologies, energy- efficient equipment and air pollution control systems.
The project also was able to achieve LEED Gold certification on one of its buildings, a dewatering facility. This is where biosolids are dewatered before they are sent to the incinerator reactor.
“We have to be able to take out as much water as we can so that the biosolids can be used as a fuel in the reactors,” Ferguson says.
“We were initially pursuing LEED Silver, but we were able to capture every point we applied for and that moved it to LEED Gold,” he adds.
Getting everyone involved with the project on the same page has been a critical concern since day one. The project mandated that all contractors and consultants had to use Primavera scheduling software to ensure that every detail ended up in one master schedule.
“This helped us make sure that we knew what aspects of the project were on critical paths and what weren’t,” Ferguson says.
“We also provided substantial performance incentive to the contractors on the liquid side of the project so we were ultimately able to complete work about a month ahead of schedule in November 2010,” he adds
The logistics of moving people and material around the site was another challenge. At its peak, the project had more than 500 workers on the site with several pieces of the project on the go at any one time.
“We scheduled moving the pieces around through a lot of initial planning,” Ferguson says.
More work remains to be done in the months ahead. Although the plant has a 630 ML/d capacity, the Ontario Ministry of the Environment (MOE) limited its outfall capacity to 520 ML/d because of mixing limitations with Lake Ontario’s water. Going forward, and still subject to the receipt of the approval and issue of the amended Environmental Certificate of Approval from the MOE, the plant is to maximize existing operations and adjust the existing outfall with variable diffuser ports.
“A lot of that has been done, almost 95 percent, but we haven’t finalized it to date,” Ferguson says.
At this point, the major priority now is moving toward the final commissioning of the solid processes, as well as getting the fluid reactors and heat recovery equipment up, running and operating to their expected performance levels.
“We’ve had excellent collaboration with contractors and consultants, which has allowed us to meet deadlines and budgets,” Ferguson says.
“The extra work orders on the project have been only 1.8 per cent of our costs,” Ferguson adds.
When the project is complete, The Regional Municipality of York will have learned how to better manage projects that require multiple contractors on a site at the same time. In addition, it will have improved its wastewater infrastructure in ways that will benefit the region’s residents and businesses for years to come.
“In the future, the benefits will include cleaner effluent,” Ferguson says. “Thus far, we have been meeting targets of performance quite handily. We will also see benefits from the energy recovery systems designed into the facility that will reduce our carbon footprint.”