Down to the wire at Banks Street treatment plant
A lot of checking and rechecking is going on this week in preparation for the “clean water” testing of the Banks Street Wastewater Treatment Plant this weekend.
Once this testing is complete and any refinements are made, the first “dirty water” or wastewater will be put through the plant. This is scheduled for 27 December, all going well, just days before the agreed 31 December deadline.
Representatives from Gisborne District Council, design consultants Beca, construction contractor HEB Structures, and major suppliers and sub-contractors will be on site over the next few weeks to ensure every aspect of the system has been completed to specification and is working as planned. Health and safety issues such as fire extinguishers, padlocks, emergency lighting and lightning protection are just as important as the completion of the plastic welding, electrical installation and software needed to run the plant.
Gisborne District Council project manager Peter McConnell says the testing covers mechanical, electrical and process components and the performance testing of the treatment plant. “All plant and equipment must pass tests to show that each is operating satisfactorily. These tests include pressure testing all pipelines on both the industrial separation works and within the treatment plant, and hydraulic testing of the industrial separation and treatment plant pump stations and structures. The odour control system will also be tested.
“Clean water commissioning comprises filling the system with clean water and operating the equipment.”
As the testing goes on, components of the new system will gradually be married together with the old.
“Wastewater will be diverted from the eastern interceptor to the treatment plant and once the plant is operating satisfactorily, the final switchovers will be made to isolate the Stanley Road facility, by diverting the wastewater through the new eastern interceptor bypass pipeline.”
The final diversion will be the outfall itself. The new pipe – which will convey treated wastewater to the existing outfall and then 1.8km to sea – is already in place. When the new Banks Street plant is fully commissioned, the outlet from the old Stanley Road plant to the outfall pipeline will be blocked off and the Stanley Road plant decommissioned.
The site will be blessed again early next Monday morning by the Reverend John Tomona, who just 13 months ago blessed the site for construction to begin.
Colin Newbold – project manager for main contractor HEB Structures – and his team will be lucky to spend Christmas Day with their families as they work to ensure everything is in place for the first wastewater to go through the plant come the morning of 27 December.
Once building consents have been granted for the completed buildings, Council’s plant operator Dave Viggars will take over the day-to-day running of the plant supported by Fulton Hogan staff.
Colin Newbold said about 70 people are currently working on the site, close to half of whom are from Gisborne.
Representatives from Council, CH2M Beca, HEB Structures and Fulton Hogan inspect the outfall pump station before clean water testing commissioning begins this weekend.