Ferrycarrig was engaged by Confluence Water to undertake the Lane Cove Source Control Project. The project involved headwall replacement, emergency relief structures (ERS) chamber replacement and the decommissioning of the existing discharge structures.

This project is part of Sydney Water’s wider Wet Weather Overflow Abatement Program to reduce stormwater ingress/inflows into the wastewater network.

This project will focus on preventing stormwater entry into the Sydney Water wastewater network by constructing ERS, refurbishing backflow prevention devices, replacing maintenance chambers and preventing cross-connections with Council stormwater networks.

Ferrycarrig was engaged to replace the existing discharge structures with new standard headwalls at three site locations which involved:

• demolition and disposal of existing headwall and pipeline
• implementing flow isolation flow management (FIFM) and bypass requirements
• excavation and construction of the new headwalls
• installation of handrails for headwalls
• restoration, regrading of banks around the new headwalls

Ferrycarrig was also engaged to replace the existing discharge structures with new ERS chambers at seven project sites that involved:

• demolition and disposal of existing ERS and pipeline
• excavation and construction in-situ of the new ERS Chamber and discharge sewer
• restoration, regrading of banks around the new ERS.

The works also involved the decommissioning, demolition, and removal of the existing discharge structures at two of the sites.

Key challenges associated with the works included challenging site access conditions that required transportation of materials, plant and equipment by helicopter.

The locations of the work sites are near waterways and stormwater gullies.

Ferrycarrig implemented stringent environmental controls to prevent any soil erosion and surface water run-off. Works were completed with no environmental incidents.