Sydney Water

Comdain's Role

Panel Member

Value Range Category



New South Wales


Distribution Infrastructure

Electrical, Mechanical & Instrumentation

Renewals Water & Wasterwater

Panel member to support the delivery of works within the Network and Facility Renewals Program for Sydney Water. Program projects include:

Shell Cove Boat Harbour Sewer Pumping Station

Principal Contractor

May 2015 – Nov 2016

Provision of a sewer pumping station for the new Shell Cove Boat Harbour precinct

Works Undertaken

  • ­Design and Construction of a 10m deep by 3m diameter sewer pumping station including all civil, mechanical and EI&C works, landscaping, fencing and access roads and paths

Highlights and Innovations

  • ­Overcame the bulk and detailed earthworks in hard blue stone rock up to 10m in depth by implementing the use of a drill and blast process which was performed safely and without incident.
  • ­In order to combat the changing weather conditions Comdain made use of Pre-cast rings to reduce the overall construction duration.
  • Includes the construction of an underground wet well utilising two fixed speed submersible pumping units, consisting of 1 duty + 1 standby. This also includes an underground emergency storage area.

Galston & Glenorie Sewer Infrastructure

Principal Contractor

Nov 2014 – Sept 2015

Design & construction of a new pressure sewer reticulation and rising transfer mains to connect two existing townships to the adjacent gravity treatment network.

  • ­20km of OD40 – OD125 polyethylene pressure sewer reticulation
  • ­15km of OD110 – OD200 pressure rising transfer mains
  • ­14m high stainless steel barometric loop with ventilation cabinet
  • ­10 vent shafts and cabinets with SS pipework internally used for ventilation
  • ­Multiple odour control units for pressure main air valves (carbon absorption)

Highlights and Innovation

  • ­Comdain reviewed the detailed design and proposed to amend construction methodology from open cut trenching to HDD to provide improved community outcomes and system reliability for Sydney Water, which resulted in 90% being constructed via HDD.
  • ­Barometric loop structure was fabricated by Comdain’s Systems Group
  • ­Approx. 6,000 PE Electrofusion joints performed on the reticulation mains.
  • ­Effective management of complex community issues to facilitate on time delivery with minimal community impacts and no complaints from the 600 plus property owners.

Woronora Wastewater Surcharge Package

Delivery Contractor

Aug 2017 – March 2018

This project aimed to control the volume of wastewater reaching the pump station and the local community during major storm events to prevent uncontrolled surcharges from occurring.

Works Undertaken

  • Site 1, Existing Northern ERS: decommissioning of the existing Northern Emergency Relief Structure (ERS) on the Still Creek Carrier
  • Site 2, New Northern ERS: construction of a new emergency relief structure (ERS) over existing 900mm carrier. New 1200mm outlet pipework and new overflow structure into Still Creek. Supply and installation of 2No new duckbill valves and remote monitoring instrumentation.
  • Site 3, Western hydraulic control and ERS: installation of a manually controlled penstock to control the volume of wastewater from the Woronora Carrier reaching the local community, augmentation of the existing ERS to better permit spilling of wastewater from the Woronora Carrier and protection work to the overflow receiving environment. Provision of remote monitoring equipment.
  • Site 4, SP0360: installation of an actuated penstock within an existing inlet chamber at a pump station to control the volume of wastewater entering the pump station from the Menai Carrier. Construction of a DN750 overflow line and new maintenance chamber constructed over existing 1200mm overflow line, and the provision of two duckbill valves. Also electrical works including the provision of a new UPS, monitoring instrumentation and hardware modifications to incorporate new assets into the existing system.

Highlights and Innovation

  • Hot works ban – implementation of other tools and processes for tasks such as cutting steel to mitigate the risk of fires due to 2 work sites being located within the bush.
  • Working attentively with local residents to reduce the impact of site workers with measures such as constant dust suppression.
  • Innovative pre-cast rings instead of poured on- site rings – cost and time effective.
  • Multiple compliments received from the community.

Leppington Wastewater

Delivery Contractor

Jan 2018 – April 2019

Detailed design, construction, testing and commissioning of wastewater infrastructure to accommodate development in the area of Leppington and Leppington North.

  • Conducting geotechnical, contamination and survey investigations along the pipeline
  • Marking out the construction corridor and removing any vegetation
  • Construction of an additional pump station on the existing North Leppington site to increase capacity
  • Using open trenching and boring technologies to construct new wastewater pipelines and to connect to the existing wastewater pipeline
  • Installing ventilation shafts and maintenance holes along the pipeline
  • Installing and constructing ancillary infrastructure, such as access roads, and temporary storage areas
  • Restoring the work corridor in accordance with pre-construction customer agreements with landowners

Highlights and Innovation

  • Negotiating with landowners to change construction methods and adjust pipeline alignment to minimise impact
  • Innovative pre-cast rings instead of poured on- site rings – cost and time effective