Public Works Committee: Andrews Farm Sewer System Upgrade

Ms HOOD (Adelaide) (11:44): I move:

That the 129^th report of the committee, entitled Sewer System Upgrade, Curtis Road, Andrews Farm, be noted.

The proposed works from SA Water, hereon referred to as 'the agency', will make upgrades to a stretch of sewer along Curtis Road in Angle Vale. Currently there is an odour issue at the discharge point of the sewer caused by the reaction between effluent flows and atmospheric oxygen. This reaction leads to an emission of the noxious gas, hydrogen sulphide. These issues are common in wastewater networks and the agency is experienced in addressing them when required.

At elevated concentrations, hydrogen sulphide is hazardous and can pose health risks if people are exposed to it. These emissions are currently being managed through chemical dosing and carbon filtration, which counteracts the odour but not the underlying problem. The proposed upgrade will solve the root cause by reducing the turbulent flow of sewage and the aeration of the effluent that causes the creation of the noxious emissions.

The project will remove an approximately 800-metre section of sewer pumping main on Curtis Road between Andrews Road and President Avenue and replace it with 450-millimetre gravity main. This will decrease turbulence by relying on gravity to move effluent rather than active pumping, reducing the introduction of oxygen into the system and removing the major causes generating hydrogen sulphide.

The project will also provide the opportunity to introduce additional inflows, which will support future network growth, while the size of the gravity main will also contribute to the system's capacity to accommodate growing demands from the Angle Vale housing developments. Additionally, the works will construct a new manhole, create new service access points, install a new ventilation system and tie into the existing President Avenue manhole. All works will be conducted within the existing road corridor, with the proposed gravity main located in the southern travel lane of Curtis Road.

Construction will commence this month with the anticipation to be practically complete in the third quarter of this year. The project is expected to cost up to $11.1 million, with an operational cost of approximately $25,000 over the next 30 years. The upgrade will remove the need for the existing operational filtration costs and the project will have no impact on SA Water's overall borrowing or contributions to government.

The committee examined written and oral evidence in relation to the sewer system upgrade, Curtis Road, Andrews Farm. Witnesses who appeared before the committee were Peter Seltsikas, Acting General Manager, Sustainable Infrastructure, SA Water, and Michael Grgic, Delivery Manager, Program Delivery, SA Water. I thank the witnesses for their time.

Based upon the evidence considered and pursuant to section 12C of the Parliamentary Committees Act 1991, the Public Works Committee reports to parliament that it recommends the proposed public work.

Motion carried.