Site and Soil Evaluation

      (i)    To avoid runoff from the area it should be as level as possible.
      (ii)   The pump and irrigation system must have a separate effluent storage chamber that matches the
             electrical starting requirements of the pump. A volume 200 L is recommended as a minimum. The
             pump is to have a minimum capacity of 1.5 times the maximum 30 minute flow rate.
      (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) The pipework is to be spaced to ensure an even distribution of the effluent over the application area.
             A maximum spacing of 1000mm in clay soils and 600mm in sand should be adopted. Greater rates of
             evapo-transpiration is achieved through closer spacing of the dripper lines and or reducing the spacing
             between the drip emitters.
      (v)    The dripper lines should have a stop cock downstream from their connection to the supply line
             (manifold) and be brought to the surface at their ends. This will enable flushing of the individual lines
             and enable easy identification of blocked lines.
      (vi) The treated effluent must not be used for the irrigation of fruit or vegetables.
      (vii) Siting of the irrigation area shall be in a location away from regular pedestrian traffic and recreational
             areas, so there is no risk of direct spray or wind driven spray onto such areas.
      (viii) The area should not be within vehicle paths or be near children’s play areas.
      (ix) Treated effluent quality must conform to AS 1547-2012 and the Queensland Plumbing and
             Wastewater Code.

We have attached a site plan showing the proposed position of the Land Application Area and also some details
highlighting the construction techniques required for shallow sub-surface or covered surface irrigation.


Preparation of irrigation area:

When a proposed irrigation area has a low permeability, it is particularly important to ensure that the permeability
of the soil in the irrigation area is improved and maintained and that there is an adequate cover of porous and
fertile topsoil to act as immediate storage of effluent applied to it, and to support rapid growth of vegetation on the
area to maximise evapo-transpiration.

It is recommended that topsoil be imported to improve rapid growth of vegetation and improve the evapo-
transpiration process.


Requirements of irrigation system:

All irrigation pipe work and fittings shall comply with all parts of AS 1477 or AS 2698.2. The distribution irrigation
lines should be buried to a minimum depth of 100mm. There shall be no cross connection between any irrigation
pipe work and the potable water supply. Any pipe work used for the transport of effluent included treated effluent
must be lilac in colour.

Along the boundary of the surface irrigation area there shall be at least two warning signs clearly visible to inform
the occupants of the premises that recycled water is used for irrigation. Each sign shall comply with AS 1319 and
have:

      (a)    lettering visible at 3m and
      (b)    wording:              Recycled Water
                                   Avoid Contact
                                   DO NOT DRINK

Prior to the use of the system, the warning signs and the landscaping and surface preparation must be completed.




   AUSTRALIAN SOIL INVESTIGATIONS                              6                                ASI Ref: 220144(A)