RFQ Abandonment of the Glen Iris Pilot Hole & Redevelopment of Glen Iris 1 Production Bore

⁠⁠⁠1) Abandonment of the Glen Iris Pilot Hole:
In 1997, a hydrostratigraphic hole was drilled to a depth of 402m to determine the quality of the groundwater in the Yarragadee aquifer locally; it has since collapsed at 12.5 m deep, immediately below the base of the surface casing.

Aqwest has determined that there is a risk of groundwater leakage between the superficial layers and the Yarragadee aquifer via the collapsed pilot hole which may, if left untreated, adversely impact the new Glen Iris production bore.

Aqwest consultant Rockwater recommended that the pilot hole be redrilled, conditioned and plugged with cement grout to restore the confining layer between the aquifers and to minimise the risk of contamination from inferior quality water.

2) Redevelopment of Glen Iris 1 Production Bore:
In 2009, a hydrostratigraphic hole was drilled to 454 m depth, at about 60 m distance from the 1997 hole, which was subsequently reamed and constructed as a production bore Glen Iris 1. Screens were installed, 0.5 mm aperture, between 404.35 m and 452.88 m depth. The
production bore has not been commissioned since construction. A recent CCTV survey showed the bore to be structurally sound; however, redevelopment and disinfection would help prepare the bore for future pumping requirements prior to equipping.