WARREN SHIRE COLLIE TOWN WATER BORE

Collie Construction of Town Water Bore and associated infrastructure

Warren Shire Council drilled a new water supply production bore 10 kilometres from Collie. The project involved the fit out of the new town bore and their connection into the existing storage reservoir at Collie adjacent to the Colie Hotel. The project included design supply and installation of bore pump associated electrical control and monitoring equipment and a 10-kilometre 100mm PVC Trunk main. There were a couple of major issues with this bore site that had to be addressed to be able supply the requested duty of 7l/s @ 152mrts into the Collie reservoir to maintain the required town supply.

1st Issue is the internal diameter of the new bore is only 143mm which is too small to take any type of submersible pump which could carry out the required duty of 7l/s @ 152mrts head .The only option open to supplying the required duty is to go to a line shaft turbine pump whereas the pump is driven through a line shaft column with the motor situated at the top of bore, this type of pump will carry out the specific duty.

2nd Issue is the power onsite is only single phase and the required kilowatts to run this pump system is 18.5kw and the biggest single phase motor available is 7.5kw, we have encountered this problem before and if the Transformer supplied was upgraded to 25kva than we can invert the power from single phase to 415volts three phase, and by using a VFD system which will supply suitable line voltage and current to run the 18.5kw motor

The project was undertaken through funding made available through Restart NSW Water Security for regions program.

Works Undertaken

• Supply and install 1 Cast stainless steel Electric Submersible Pump driven by a 18.5kw surface mounted motor, the drive shaft from the pump to the motor is 25mm and the pump column is Schedule 40 x 80mm stainless steel complete with all required stainless-steel fittings.
• Hydraulic Manifold arrangement at the bore head including Water meter, Valves, and all associated connection fittings to link to the new 100mm PVC Trunk mainline.
• Design supply and install suitably sized consumer mains from the supply authority transformer including transformer upgrades to each individual bore pump electrical shed.
• Design supply and install Electrical pump shed Switchboard and Motor control centre including Variable Speed Pump drive and all to interface with councils clear Scada control system to monitor bore water depth and current and cumulative flow rates to council reservoir.
• Trench and lay 10 kilometres of 100mm PVC Trunk main from the bore site to the existing Collie Reservoir.
• Testing and Commissioning of Pump system and mainline.

Highlights, Innovations and Key Risks

• Project finished on schedule despite required Electrical Transformer upgrades.
• Infield modifications to adapt to onsite electrical issues.
• Supply and source a pump system that would fit into the existing new bore hole.
• No major disruption to town water supply through the project duration.
• Excavation and pipe laying in proximity to existing infrastructure.
• No underground service strikes for the duration of the project