NorthConnex Tunnel Project, Stage Two Water Treatment Plants

September 19, 2018

NorthConnex Tunnel Project, Stage Two Water Treatment Plants

Enviropacific has played an important part in the NorthConnex Tunnel construction project demonstrating our capability to remediate water efficiently and effectively.

We were involved from concept design to project completion. We are proud to be delivering a sophisticated, fully automated water solution to one of Sydney’s major infrastructure projects that will help relieve traffic congestion.

Enviropacifc supplied and operated four 36m3/hour water treatment plants as part of stage one of the NorthConnex project. Now with stage two underway, Lendlease Bouygues Joint Venture has engaged us to design, install and operate a larger 115m3/hour plant.

There is a significant demand for water on the project with the operation of heavy machinery such as road header machines, bolter machines and shot-crete rigs utilising water for cooling and dust suppression during the tunnelling and fit out. Site amenities, general wash down, wheel washes and general construction works such as concreting and compaction all also use a substantial quantity of water. Therefore, the water quality and availability play a pivotal role in the tunnel construction works.

The used water is significantly contaminated with suspended solids, heavy metals and dissolved solids; as a result it requires proper treatment prior to discharge or reuse. This water has a higher alkaline pH value of at least 11 and contains metals such as Copper, Manganese, Nickel, Iron and Zinc. In addition, higher solid loading (~15,000mg/l) in feed water (resulting from the tunnelling process) requires a properly engineered sludge dewatering system.

Our physio-chemical treatment process removes these solid and chemical contaminants from the discharge, producing water well within the ANZECC 2000 guidelines for stormwater discharge. We assisted our client to achieve sustainability targets as a portion of the treated water is recovered and recycled on-site for dust suppression, landscaping and sweepers. Excess water is discharged under license into the local stormwater and creek system and the solids removed during the water treatment process are further refined and classified for disposal from site.

This is yet another outstanding example of an EPCM project Enviropacific undertook from a concept design to completion which was well executed inhouse. The substantial project completion was achieved on 24th May 2018 within two months from the time the first site access was granted.