Australian Water Management Review Vol. 1 2014 | Page 147

Image 1. EOne pot/tank ready to be installed Image 2. Installed pot/tank with alarm control panel efficient system that Sydney Water owns and maintains • potential cost savings for property owners with regular pump-out and maintenance costs • fewer potential odours from on-site systems and pump-out trucks • cleaner waterways and local environment • reduced public health risks from leaking on-site systems • the removal of dampness and seepage • the opportunity to reuse existing on-site systems to collect stormwater and/or greywater • a potential increase in property values. Cowan Location and setting Cowan is located in the Hornsby Shire Local Government Area on the northern fringe of Sydney. The village is situated on the Hawkesbury escarpment surrounded by several national parks. Major features of the area include the Muogamarra Nature Reserve, the Ku-ring-gai Chase National Park and the Berowra Valley Regional Park. Figure 1. Typical on-property pump installation Wastewater equipment has been installed on 217 properties and residents are now connecting to the system. How it Works • A pressure sewerage system was installed at Cowan. The system works by collecting wastewater in a small tank installed on each property. A pump located inside the tank grinds the wastewater into a slurry and pumps it through a network of pipes to a wastewater treatment plant. (See Image 1, Image 2, Figure 1 and Figure 2) • The pressure sewerage system transports wastewater from properties into newly installed reticulation and transfer mains along the Pacific Highway. Wastewater travelling through the transfer main goes via the chemical dosing unit (CDU) at Berowra Truckstop. Wastewater then flows down to the existing system at Gully Road via a gravity wastewater main. Wastewater is then transferred to the Hornsby Heights Wastewater Treatment Plant for treatment. Figure 2. Cross section view of the collection/pump unit Australian wat e r m a n a g e m e nt r e vie w 141