Penshurst Sewer Project

The township of Penshurst in the Southern Grampians Shire Council region of south-west Victoria is the most densely populated unsewered town within the municipality, and is situated on a sensitive groundwater setting near an extinct volcano. The town is located on the busy Great Southern Touring Route which connects Great Ocean Road with Dunkeld. Despite this strategic location, the town has experienced little tourism investment due to the lack of a sewer scheme for cost effective effluent treatment on often small lots. This is reflected in limited tourist accommodation and retail investment generally.

A Council audit of Penshurst’s septic systems found 93% (approximately 190 systems) were not performing satisfactorily and did not adhere to current public health and environmental standards. In addition, around 95% of owners did not maintain their systems, leading to a high risk of contamination of the groundwater and local water bodies. A natural spring of significance to the region’s Traditional Owners, the Eastern Maar, is also experiencing elevated nutrients which could risk triggering a future blue green algae outbreak.

Both Council and the community of Penshurst are keen for the township to grow and develop.

Penshurst’s current approach to domestic wastewater management limits residential and economic growth as the lot sizes within the town already provide insufficient land area to effectively treat and dispose of effluent via onsite systems. In addition, a reticulated sewerage system is also not suitable for the Penshurst area given the prohibitive costs of installation and distance from established systems in Hamilton.

Sewer the Penshurst township via 12 cluster sewerage precincts and treated recycled water, irrigated via subsurface irrigation. To test the effectiveness and suitability of the Penshurst Recycled Water Scheme, a pilot project is proposed where two precincts are to be chosen to develop a proof of concept and adaptive pathways approach to wastewater management.

The Penshurst Recycled Water Scheme is a neighbourhood-scale solution that divides 270 properties across Penshurst into 12 precincts based on topography and the nature of the land use. For each precinct, existing onsite systems would be decommissioned, and separate gravity all-waste sewers would be installed. These sewers would direct raw sewage from properties to a local precinct water recycling system, which would conduct primary treatment of wastewater, then disposal through evapotranspiration “pods”. These natural pod systems provide further treatment in the soil and allow water to be taken up by plants and evaporated. They also allow water to be stored within the pods during cooler, wetter periods.

Recycled water can be stored for public irrigation of open spaces when necessary, such as during warmer months. This open space irrigation would occur underground, via sub-surface drippers.

$2.1m for the Penshurst Recycled Water Scheme pilot project.