Self-contained sewerage system for Mundaring

10/11/96

Perth's environmentally sensitive Hills catchment area is now the home of a self-contained sewerage system.

Water Resources Minister Roger Nicholls said the self-contained system - which was not attached to Perth's main sewerage system - would produce effluent low in solids, bacteria and nutrients.

The effluent would be used to reticulate Mundaring's ovals, enabling the shire to save money while keeping the town green.

Mundaring had been chosen because of its location and relatively isolated population, and because septic tanks would not be able to cope with increased demand in the area.

Initially, the plant would serve the Mundaring's central business district, two schools and an aged persons' hospital.

The $870,000 Water Corporation-owned plant had been designed over the last six years to meet the needs of communities ranging in size from 100 people to 50,000.

Similar systems would be suitable for towns like Denmark and Pemberton in the South-West and might be copied in small community pockets throughout the hills area.

"The Water Corporation has come up with an innovative treatment plant which will suit small communities but which can be easily upgraded and expanded if necessary," Mr Nicholls said.

"We plan to have more such systems across the State.

"The effluent is low in nutrients and bacteria which makes it suitable for ovals and other public spaces without the need to confine watering to between 6 pm and 9 am."

Mr Nicholls said the effluent was produced, using an intermittent aeration process which removed nutrients such as nitrogen and phosphorus biologically.

It was then given secondary treatment, was disinfected, and passed through specially planted reed beds which further purified it before it was made available for watering.

If the shire was not able to take all the effluent at any time, the system included a subsurface effluent drain where it would soak into the ground.

The plant was being constructed by Tubemakers Water, which had already completed the main treatment works which included the aeration system and transfer tanks and a small amenities building.

The Commonwealth Government's National Land Care Program had contributed $500,000 towards the project.

Media contact: Hugh Ryan 322 6529