Aurizon Holdings Limited have engaged Dowdens Pumping & Water Treatment [Mackay & Brisbane Branches] to deliver a Water Treatment Plant (WTP) at their Coppabella Township, located on the Goonyella Rail Corridor (the world's largest metallurgical coal rail system) - 159 kilometres South West of Mackay, QLD.
The township of Coppabella was primarily designed and built to service the junction of two railway lines (one from Goonyella Coal Mine and one from Saraji Coal Mine) and to provide accommodation to the regions coal mine workers in work depots. The town was established in three stages, with the first being completed in 1971, the second in 1977 and the third and final stage in 1984. The town is wholly owned and operated by Aurizon Holdings Limited and contains: stations, residences, single-quarters, work depots, hotel, a shop, swimming pool, football oval, caravan park, school, ambulance, fire brigade and of course the new Dowdens Water Treatment Plant which is capable of producing of up to 900kL of potable water per day.
Dowdens engineers and service crews designed, manufactured, installed and commissioned the Coppabella WTP to treat raw water to Australian Drinking Water Standards. As the Principal Contractor Dowdens were provided a set of feed supply water parameters coming into the WTP, and water quality requirements for the delivery of the town's drinking water. From these basics the $2.5 million project came to fruition. The Dowdens WTP replaced the existing water softening plant (located adjacent to the new WTP), whilst future-proofing the growth of the Coppabella township by increasing the WTP's maximum daily drinking water production capacity up to 900 kL/day.
The new WTP is completely automated and user adjustable via the GE Human Machine Interface (HMI) situated in the purpose built site Control Room / Office, minimising the need for direct operator interaction / intervention on-site. A dedicated remote monitoring / alert messaging system was also provided so that in the event of a critical alarm the EDAC 700 RTU will call the WTP Operators advising them of system alarm status via pre-recorded spoken messages.
Security of the WTP site was significantly improved with the establishment of a controlled compound restricting access to authorised personnel only (pictured below). Dowdens also eliminated the need for repetitive manual handling of typical WTP chemical consumables on-site (Salt, Liquid Chlorine and Soda Ash) via the integration of various bulk storage systems.
Dowdens were successful in the tendering process due to:
Dowdens coordinated the design, build and commissioning of the WTP from project inception through to final handover. This included, but was not limited to: preliminary design - detailed design - risk assessments (with client and consulting engineers) - preliminary civil works establishing the site (levelling site) - under boring Peak Downs Hwy for installation of raw water pipeline - installation of all underground services - pouring of slabs - construction of the Ion Exchange (IX) building - installation of process equipment - installation of all interconnecting pipework - electrical installation of control panel and field instrumentation / equipment - commissioning of instruments / equipment - commissioning of PLC program and HMI - successful completion of 'Proof of Performance' testing and all necessary operator training.
The inclusion of a unique Brine generation system was a novel approach that incorporated a salt bulk bag unloader (capable of lifting 1200kg bags - pictured below) and a proprietary piece of equipment from the USA [BRINE ExtremePro]. The IX system is flexible in its design and is capable of producing between 150 - 900 kL/day of potable water with the IX system constantly analysing and compensating for variations of incoming bore water hardness levels.
The existing water softening plant (located adjacent to the new WTP) and raw water supply needed to be retained during the new WTP construction. The old plant was decommissioned over a period of 3 months. Nearing project completion a wet weather event (February 2016) resulted in additional water flows through the WTP site causing some minor displacement / erosion of soil and stone that required a brief plant shutdown to rectify the damage. Dowdens performed this work efficiently and effectively eliminating any risk to the township's drinking water supply.
Dowdens Pumping & Water Treatment design philosophy for this project was: Cost Effectiveness - Current Best Practice - Ease of Installation - Simple & Effective Plant Operation - Plant Reliability & Reduced Ongoing Maintenance.
Water Treatment Plants Key Components are listed below: