The project involved detailed design and documentation consultancy services for TasWater’s Capital Delivery Office. The initial scope was to demolish the existing pumping station and provide a new pumping station and associated rising main to deliver raw water to the Zeehan Water Treatment Plant. Following a thorough site inspection and geotechnical investigations, it was found that the area around the raw water lagoon was in unstable fill material. Construction of a new inlet structure and associated wet well would be problematic and likely undermine the existing Asbestos Cement rising main.
JMG worked closely with the client to investigate alternative options and it was resolved to repurpose the existing structure. The old style vertical turbine pumps were removed and submersible pumps installed in an existing redundant wet well that was “discovered” under the pump station top slab. The old, rusted out superstructure of the pump station was removed, and the top slab remodelled to allow safe access to the wet well, inlet screen and new switchboard. A valve pit was installed adjacent the wet well, which allowed for a compact design and increased access to the top slab when the lids are down.
The rising main design utilised as much existing infrastructure as possible. A new stainless steel enclosure provided safe access to the dosing and sampling equipment. The project also involved design of a new static mixer to assist polymer dosing prior to clarification.
Through smart design and good working relationships, the project team succeeded in delivering a cost effective solution to a complex problem in a remote location.
Commissioned July 2022, the new water pumping station brings Zeehan's water treatment plant into the 21st century. Operators now have trouble free pumping, safe access and a pleasant location to watch the fish jump in the lagoon!