Overview
Vertex was contracted to design, supply and operate a filtration system to treat petroleum hydrocarbon (PHC) impacted groundwater. The project objective was to lower the static water table to facilitate the excavation of PHC-impacted soils, followed by construction of a high-rise condominium in Toronto.
System Parameters:
- 320 m3/day @ 220 L/min
- Recirculation Tank
- High-Head Pump
- Automatic Backwashing Sand Filter Vessel
- Granular Activated Carbon Vessels
- City of Toronto Approved Flowmeter and Sampling Port
Compounds of Concern:
- Petroleum Hydrocarbons
- Total Suspended Solids
Outcome
The excavation of PHC-impacted soils occurred over a 6-month period. Groundwater was extracted via multiple perimeter educator wells and pumped through a filtration system to remove PHCs and TSS prior to sewer discharge under a Toronto Sanitary Sewer Discharge Agreement (SDA). The groundwater table was lowered by 5 m to allow for the excavation of PHC impacted soils. A total of 28 million litres of PHC-impacted groundwater was treated and discharged. That’s enough water to fill 11 Olympic sized swimming pools!
After the soil excavation, the perimeter educator system was shut down and groundwater was periodically pumped via sump pits to facilitate Condo construction. After 12 months of condo construction, groundwater was transitioned over to a permanent SDA utilizing sump pumps within the building basement. Contaminants of concern were monitored throughout the project and no exceedances to the Toronto Sewer Use By-Law were detected.