Prospect South to Macarthur (ProMac)

Sydney water is building 15 km of additional pipework, three pumping stations and upgrading its existing network to ensure growing communities in South Western Sydney have access to clean drinking water.   ProMac will upgrade Sydney’s existing water reservoirs at Liverpool and Cecil Park as well as build two new reservoirs at Oran Park. This will allow for an extra 100 Megalitres of additional reservoir capacity in Western Sydney. The new infrastructure will support growing, dynamic South Western Sydney.
ProMac will help Sydney Water deliver on its vision of creating a better life with world-class water services.

Athassel Civil were engaged to carry out the works by Acciona Construction for Sydney Water.

The scope of works includes

• Laying 2.0km of DN1200mm welded Sintakote SCL watermains through Western Sydney Parklands,
• 5km of DN900mm welded Sintakote SCL watermains through Western Sydney Parklands
• 500m of various sized welded Sintakote SCL and DICL pipework to existing reservoir,
• Installation of Valves and fittings
• Construct 8 x Large FRP valve pits up to 5m deep
• Micro-tunnel 150m of 1500mm OD RCP pipe under the M7 Motorway
• Sleeved 150m of DN900mm welded Sintakote SCL watermain under the M7 motorway
• Microtunnel 2 bores 100m long of 1800mm OD RCP Pipe under the existing Jemena gas pipelines
• Sleeve 100m of DN1200mm welded Sintakote SCL watermain underneath two existing Jemena gas mains
• Installation of cathodic protection to the SCL pipe including 22 test points and 8 surge diverters
• Constructing 200m of 5m wide access road to reservoir
• Haulage of 20 000 tonne of excess material to stockpile site
• Load and cart 20 000 tonne excess spoil offsite
• Weld, hydrostatic and compaction testing to Sydney Water standards
• Managing flora and fauna within the parkland
• Tree removal
• Clearing and grubbing
• Reinstate 120m of 2.5m wide of concrete share path
• Construct 700m of 2.5m wide sandstone shared path
• Install approx 800m of rural fencing
• Reinstate parklands

The complexities of the job included working in the Western Sydney Parklands in environmentally sensitive areas, while being considerate to the native flora and fauna in the area, steep terrain, liaising with Transurban and under-boring under the M7, liaising with Jemena and under-boring the existing Jemena gas pipelines, managing and redirecting recreational park users while still enabling the park to be utilised by the public, working with other contractors in the existing Reservoir area in limited space.

Athassel fitted lifting crane systems to one 42 ton excavator and two 36 ton excavators to allow lifting of pipes over 6 ton pipes in a safe and efficient manner.  This was also beneficial for lifting the heavy boxes required for shoring the boring shafts.

A further challenge was how to insert the 900mm pipes under the M7 through the bore, which Athassel overcame by fitting the pipes with custom made spacer brackets with steel wheels to enable the 150 lineal meters of welded 900mm SCL pipe weighing 60 tons to be pulled through the 1200mm envelope pipe with a 42 ton excavator resulting in this section of works being completed ahead of schedule.