On-Site Effluent Disposal Report

6.0     DISPOSAL SYSTEM RECOMMENDATIONS:

Based on our site assessment and testing we recommend that the most appropriate method of treating and
disposing of effluent to be:

Advanced Secondary Aerated Wastewater Treatment Systems with Covered or Sub-Surface Drip Irrigation.
(As per Noosa Council requirements)

6.1     IRRIGATION SYSTEM CALCULATIONS:

We recommend approved on-site Advanced Secondary Aerated WasteWater Treatment Systems (AWTS) or
approved Aerobic Sand Filtration Systems be used to reduce the pathogen loads in wastewater produced within
the proposed allotments. Effluent quality from the plants must comply with the criteria presented in AS 1547-2012.

We recommend a Covered Surface or Sub-Surface Drip Pressurised Irrigation Irrigation Systems be used in
conjunction with the approved Treatment Systems to distribute the treated effluent in equal dosing across the Land
Application Area. A typical Site layout and arrangement drawing is attached.

TYPICAL CALCULATION:

  Minimum requirement      q       120           litres per person per day   AS 1547 –2012 Appendix H1

      Water Supply              Tank Water

  Number of persons =               6                                            AS 1547 Table J1


      Total Volume         Q=     5040       L/week

      Soil Category                 5                                            AS 1547 Table M1

 Indicative permeability        0.06-0.12                                        AS 1547 Table M1

          DIR                      21        mm/week                             AS 1547 Table M1

                                              2
      Disposal Area        A=      240       m


WE WOULD THEREFORE RECOMMEND THAT A MINIMUM LAND APPLICATION AREA OF 240 m2 FOR A
CATEGORY 5 SITE BE PROVIDED FOR A TYPICAL 4 BEDROOM DWELLING WITH A MAXIMUM
POPULATION OF 6 PEOPLE.

An additional reserve area of 100% must be provided within each allotment.

Any Irrigation System should be designed in accordance with AS 1547 – 2012 and comply with all relevant
statutory requirements

7.0     CONSTRUCTION GUIDELINES COVERED / SUB SURFACE DRIP IRRIGATION:

A pressurised irrigation system may be used as a means of widely distributing the effluent where vegetation can
directly benefit from such watering. To prevent runoff, the area to be irrigated should be:
         (i)       level as possible
         (ii)      sloping areas should be terraced and filled or retained and filled
         (iii)     rainwater shall be diverted around the area by use of open catch drains or similar from the
                   irrigation area. Similarly a retention bund should be constructed around the low side of the area to
                   retain any effluent overflow.
         (iv)      effluent quality shall conform to AS 1547 2012 and local statutory requirements


AUSTRALIAN SOIL INVESTIGATION                                   6                                        ASI Ref: 210264(A)