The Water Corporation is proposing to divert wastewater from the Bullsbrook Waste Water Treatment Plant (WWTP) to the Beenyup WWTP, 20 km away. A new pipeline will be installed predominantly along the Great Northern Highway to the Millhouse Road Pump Station in Ellenbrook.

The pipeline alignment traverses Main Roads WA and local government road reserves. The alignment is adjacent to Ellen Brook Nature Reserve, several Bush Forever Sites and intersects Bush Forever site 300 at Ellen Brook, however installation at Ellenbrook Drive will be through a subsurface crossing. 

The alignment has been redesigned to be in road reserves as much as possible and avoid all intact areas of remnant vegetation, Threatened Ecological Communities and vegetated wetlands. Incidental roadside trees and some riparian vegetation will be removed.

The pipeline also aligns with the mapped Western Swamp Tortoise (WST) EPP boundary with 800 m of the pipeline corridor passing through the southern EPP area.