EllisDon managed a project requiring the removal of approximately 7.8 million litres of groundwater per day from a high-water table excavation site. As the municipal sewer system could not accommodate this volume, the team designed and implemented a treatment system to safely discharge the water to a nearby lake in full regulatory compliance. 

EllisDon secured a permit to take water and lake discharge approval, developed a detailed Dewatering Plan, and engaged a qualified treatment specialist to meet Provincial Water Quality Objectives (“PWQO”). A mobile treatment system removed identified contaminants—such as phosphorus, aluminum, polycyclic aromatic hydrocarbons (“PAHs”), and Semi-Volatile Organic Compounds (“SVOCs”)—through a multi-stage process involving coagulants, flocculants, bag filters, and carbon vessels. Regular maintenance, including filter changes and backwashing, ensured continuous system performance. 

A comprehensive monitoring program included daily turbidity and pH checks and weekly lab testing to confirm ongoing compliance. These measures allowed safe, uninterrupted excavation while protecting the surrounding aquatic environment, demonstrating EllisDon’s commitment to environmental responsibility and innovative construction practices.