AA1384_Effluent Report_final

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        4.2       Protection of Surface and Groundwater Quality

        The on-site sewerage facility shall incorporate measures to control the effects of an
        on-site wastewater system on surface water and groundwater flows and the quality
        of natural waters such that subsequent use of those waters is not impaired or
        compounded (AS/NZS 1547:2012 Clause 2.4.1 (k)).

        The nearest waterbody is located approximately 60m to the north of the dwelling on
        proposed Lot 1 (6m from the northern site boundary). Due to the depth of the
        groundwater at the nearest bore, it is considered unlikely that groundwater will be
        impacted, however trench beds must be designed in accordance with AS/NZS
        1547:2012 to reduce nutrient runoff.

                                          Table 4.2
                 Recommended separation distances for protection of water quality

                              Feature                              Recommended Separation
                                                                  Distance based on treatment
                                                                             level

                                                        Primary       Secondary    Advanced
                                                                                   Secondary
          Top of bank of permanent water course;           50m           30m           10m
          Top of bank of Intermittent water course;
          Top of bank of a lake, bay or estuary;
          Top water level of a surface water source
          used for agriculture, aquaculture or stock
          purposes;
          Easement boundary of unlined open
          stormwater drainage channel or drain.
          Bore or a dam used or likely to be used          50m           30m           10m
          for human and or domestic consumption
          Unsaturated soil depth to a permanent            1.2m         0.6m          0.3m
          water table (Vertically)
          Note:
                   The separation distances are recommended and
                   the local government may upon considering the
                   public health and environmental risks reduce or
                   increase the distances given in the above table.

        We consider the property offers sufficient area to provide the required setback
        distance from the treatment area to the nearest waterway.


5.0     ON GOING MAINTENANCE AND MONITORING

Monitoring and maintenance of the on-site wastewater treatment and disposal system is to
be undertaken in strict accordance with the manufacturer’s recommendations, requirements
of State and Local Governments, and AS/NZS 1547: 2012. For sub-surface application,
once the soil becomes saturated with nutrients, or becomes saline, we recommend the soil
is remediated or replaced or that a reserve wastewater disposal area is commissioned.


6.0     CONCLUSIONS AND RECOMMENDATIONS

In our opinion, we consider that an advanced secondary on-site wastewater treatment and
disposal systems to be suitable and viable for the proposal. We also consider that sufficient
area is available on site for the installation of trench beds whilst complying with required set-
back distances.




AA1384EFF
September 2016
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