The District of Squamish is undertaking an extensive upgrade of the Mamquam Wastewater Treatment Plant. The WWTP upgrades consist of construction of a new circular bioreactor/clarifier tank, associated piping and a new septage receiving station. Ground under the proposed circular tank has been excavated to approx.1.5m below grade. Impacted utilities under the proposed circular footprint have been decommissioned and relocated.

Challenges/Constraints

The work must be done in a manner that allows the treatment plant to continue operating and meeting the discharge permit throughout the duration of the work.

WWTP

• Excavation and rough grading for new bioreactor clarifier.
• Placement and compaction of granular materials and geotextiles
• Concrete tank construction, including in tank piping and miscellaneous metal platforms, handrails, etc.
• Supply and installation of process equipment.
• Installation of clarifier mechanism and associated accessories pre-purchased by owner.
• Construction of Flow splitter chamber for secondary treatment.
• Modifications to rectangular clarifier to convert into Primary Clarifier.
• Primary sludge conveyance pipe to DAFT.
• Inlet piping from Grit tanks to proposed Primary Clarifier.
• Conveyance piping from Primary Clarifier to Flow split chamber.
• Conveyance piping from Flow split to two bioreactors.
• Associated plant piping and tie-ins to existing piping, structures and equipment.
• Power and control wiring and electrical kiosks.
• Civil finish grading around designated work areas.

Septage Receiving Station

• Rough excavation and site preparation
• Placement and compaction of granular materials.
• Underground buried piping and tie-ins.
• Power and control conduits and wiring from new SRS building to existing Control Building.
• Construction of new SRS building and all mechanical/electrical building equipment/components.
• Installation of District supplied Septage Receiving Equipment.
• Construction of new access road for septage trucks.
• Fence modifications