Sewage Ejector Pump and Waste Plumbing
Installation of drain waste vent (DWV) plumbing under basement concrete slab. Significant challenges included the basement slab being below the grade of the septic system, requiring the use of a sewage ejector pump, and the fact that the slab was poured directly onto bedrock, leaving no space for sub-concrete pipes. To overcome this, the existing concrete floor was cut and broken up in the location of the ejector pit and along pipe runs. The underlying bedrock was then excavated using a jackhammer to depth sufficient to achieve proper pipe slope for drainage and to set the ejector pit inlet below the concrete. Excavation resulted in the removal of approximately 4 cubic metres of bedrock. Drain pipes for a shower, lavatory, toilet, utility sink, two floor drains, and appropriate vent pipes were installed in the excavation, passing inspection by conforming to local building codes.The sewage ejector pump was sized to handle the hydraulic load from these fixtures. Upon passing inspection, concrete was poured to cover the excavation. The project enabled the installation of a conventional full bathroom and mechanical room without the need for specialized below-drain-grade equipment.