Appendix G - Geotechnical Report

Risk Assessment

                      Risk                                         Risk Mitigation
                 Surface Runoff                                        Mounds
                 Human Contact                         Signs and mound to identify area. Apply by
                                                                       setbacks
         Overloading of system and LAA                   Use correct DIR, flow allowances and
                                                                 maximum occupancy

Recommendations

   •   An approved Advanced Secondary ASTP is to be installed. (Installer to ensure tank
       position does not damage to existing or proposed structures)
   • A covered surface irrigation area of 240m2 consisting of pressure compensating lines
       laid atop of the existing ground surface level and spaced approximately 800-1000mm
       apart and covered with 150mm of mulch.
   • The tank must be installed and anchored if necessary, to prevent flotation.
   • Installer to confirm sufficient fall is available to the treatment plant prior to installation once
       the floor height is known.
   • Top of treatment plant shall be at least 150mm above any flood levels that are present.
   • A filter must be installed in between treatment plant and irrigation area.
   • Pump must have sufficient power to pressurise irrigation lines.
   • All pipework and fittings used must meet relevant Australian Standards be buried, withstand
       150% of pump shut-off-head and be fit for use.
   • The supply line from the treatment plant to the irrigation area shall be buried 25-32mm
       purple line poly within a 200mm layer sand bed to prevent damage.
   • A flush out valve should be installed on the end of the irrigation area and used regularly.
   • Flexible joints should be used from the treatment to the proposed/existing structure where
       the site is “H1” or higher.
   • A reserve area equal to the above area is to be kept free of development and vehicle traffic
       as per plan.
   • The area shall be surrounded by a 150mm high earth mound.
   • The area shall be mulched to a depth of 150mm and evergreen plants planted to maximise
       evapotranspiration.
   • Two signs are to be erected stating ‘Recycled water-buried pipes-Do not dig’
   • All Storm water from the residence and uphill slopes is to be diverted away from the area.
   • Set back distances as per local council policies and AS1547 -2012 are to be met some of
       these setbacks when Advanced Secondary ASTP with Surface Irrigation are;
10M from a watercourse, dam, table drain, bore etc.
10M from a dwelling or habitable building.
2M from a boundary/driveway if it slopes away or is level with that boundary/driveway.
4M from boundary/driveway if it slopes towards that boundary/driveway
6M from an inground water tank
6M from pool edge.
Authorised Signatory

Matthew Bennett
on behalf of Ground Drill Pty Ltd
QBCC Lic # 15034580