The city is projected to spend about $18.8 million in wastewater system projects over the next five years, following council’s endorsement of a new master plan.
The new wastewater master plan, which was adopted in principle at the March 28 council committee meeting, has been in the works since 2018 and will replace its 2013 predecessor.
It proposes $3.3 million in updates for the city’s pumping stations, $1.5 million for the wastewater treatment centre, and $13.9 million for additional studies and projects, all proposed to be carried out over the next five years.
The master plan also estimates the costs and timing of additional needed work across a 30-year window.
While it doesn’t set its proposed projects in stone, the plan will serve as a guiding document for updating and expanding the city’s wastewater system.
In a presentation to council committee, consulting firm Ainley Group outlined the state of the city’s wastewater system and the proposed work needed to keep it running smoothly.
Council committee was told much of the city’s infrastructure is in decent condition.
“The study projected the expected wastewater flows in the system to the year 2049,” said senior project manager Preya Balgobin.
“The projected flow in the year 2049 is … approximately 79 per cent of the wastewater treatment centre’s rated capacity, and that would not necessarily trigger the need to expand the treatment centre at this time,” she said. “Usually, you start planning for an expansion of your treatment system when it hits around 80 to 85 per cent of the rated capacity.”
“We also found that the septage-receiving station condition was good, and it’s operating within its capacity, outside of there being large deliveries from large festivals,” she said.
However, Balgobin said $2.1 million in upgrades will be needed for the city’s wastewater treatment plant, with $1.5 million in work recommended over the next five years.
The recommended upgrades include $385,000 in electrical work, $149,000 in work to the centre’s sludge-storage lagoons, and $633,000 in upgrades to the centre’s head works and primary treatment centre, among others.
The city’s 24 pumping stations will require a total of $5.5 million in work, with $3.3 million recommended in the next five years.
Balgobin said the city is behind on sewer pipe replacements recommended in the 2013 master plan.
“To date, the city has implemented 28 per cent of the pipe replacements recommended by the year 2023,” she said. “The rate of the replacement is lower than recommended in the 2013 study due to the city's decision to privatize the Front Street and Centennial Drive projects.”
The city also has a problem with inflow and infiltration of outside water into its sewage system, Balgobin said, which can affect the system’s capacity.
“Even though (inflow and infiltration) was reduced since the last master plan, it’s still a significant problem within the system,” she said. “In a perfect system, the amount of water you receive at the wastewater treatment plant would be 80 per cent of what you actually used, but here it’s 31 per cent higher than what is being used in the water system.”
Among the $13.9 million in recommended projects over the next five years is $1.5 million to carry out an inflow and infiltration study and to continue reduction efforts.
The study would identify what the existing sewer system’s “issues are, where they’re located, and correct for the condition and age of the existing sewers,” Balgobin said.
The other recommendations include $180,000 for a biosolid options study, $13.1 million for constructing a secondary digester to break down organic waste, and $936,000 to expand storage lagoons.
“The digesters won’t have enough capacity to service your 2049 flow, and they actually only have enough capacity to service your flows that are currently being received, so expansion of the digestion will be needed,” Balgobin said.
She said that a biosolids option study could lead to system improvements that would ultimately reduce the need for storage lagoons, and turn solid waste into a fertilizer product.
“There are certain digestion technologies that will produce you a fertilizer-grade end product that you can market,” she said. “You will no longer need those lagoons or any kind of storage, (except the needed) storage while you offload it and sell it, but you can free up the space you have as the city grows in the long term.”