Wastewater Treatment Plant

Wastewater from homes, businesses, and public buildings is collected through an extensive network of underground pipes and transported to the treatment plant.

As the wastewater enters the plant, it first gets screened to remove any larger items like wipes & sanitary projects from proceeding further into the plant. After removing larger items, smaller materials, such as sand and pebbles, are separated in the grit separator. This process helps protect the plant's infrastructure from damage as the wastewater proceeds through the plant.

The flow splitter box divides the incoming wastewater into separate streams and directs them to different treatment areas or tanks. This helps balance the flow between different sections of the plant, ensuring that each section receives the right amount of water for effective treatment. It prevents overloading any one section and keeps the treatment process running smoothly. Any excess flows spill over into an equalization tank.

The equalization tank regulates the flow of wastewater. It stores excess water during peak times and releases it gradually during low-flow periods. This helps ensure a consistent and manageable flow of water through the treatment plant, preventing overloads and improving the efficiency of the treatment process. Any liquid waste in the equalization tank is pumped back into the splitter box for distribution to the main treatment process.

The screened and degritted raw sewage is transferred by gravity to the Integrated Fixed-film Activated Sludge reactor tanks, otherwise known as IFAS. These reactors are used to improve the breakdown of organic matter. They combine two treatment methods: activated sludge and fixed-film.

In the activated sludge process, microorganisms are suspended in the water to consume pollutants. In the fixed-film method, these microorganisms grow on plastic media inside the reactor.

This begins the settlement and separation process of the solids from the liquid before entering into the secondary clarifiers.

In the secondary clarifier tanks, liquids and solids are fully separated. Liquids spill over weirs at the top of the tanks. The liquid then proceeds further into the plant, where it goes through Ultraviolet light treatment, effectively disinfecting the water and making it environmentally safe to discharge into the ocean at Duffin Passage. The solids in the secondary clarifier tanks settle as sludge at the bottom of the tank before being moved into a dewatering system.

The sludge is dewatered using a centrifuge. The dried biosolids are then transported to the West Coast Landfill for final disposal, where they are used for landfill capping.