In commissioning a new WWTP in Snells Beach, our Client identified there was a high saline content in the wastewater from three pump stations in Snells Beach and Algies Bay that would affect the performance of the new WWTP.
The existing piped network lies within the marine reserve and are exposed to saltwater infiltration via the pipes and manhole chambers with the manholes submerged at high tide.
March Cato’s scope of works was to:
- Carry out investigations (i.e. CCTV inspection of 748m of sewer pipe assets (DN225 and DN300 asbestos cement), 16 manholes and four wet wells)
- Provide detailed design and construction of the following elements: Renewal of the existing sewer network pipes using a structural trenchless liner
- Replacement of existing chambers with sealed chambers
- Abandoning selected chambers
- Rehabilitate selected existing chambers to prevent further infiltration of sea water
- Carry out additional repairs identified from the investigations
As Head Contractor, March Cato’s work scope also included responsibility for all project planning and programming; engagement of specialist subcontractors; management of health and safety, environmental and quality; obtaining Watercare, Auckland Transport approvals and Resource Consent for working in the CMA; reviewing / checking of all captured data (i.e. CCTV footage and condition assessment rating) for accuracy and completeness prior to reporting / presenting to Watercare, design and build; stakeholder management, TTM, temporary works installation, design of manhole repair solutions including replacement, repair and sealing / upgrades, and reinstatement.
