Wastewater Report

3.3 Soil Classification

                                                    Soil Classification - Adopted
       Borehole Nos                                                                                  1&2
       Soil Category Adopted                                                                           5
       Indicative Drainage                                                                      Poorly Drained
       Structure                                                                                  Moderately
       Texture                                                                                    Sandy Clay
       Indicative Permeability P (m/d) as Ksat*                                                   0.06 - 0.12
       Recommended DLR (AS/NZS 1547 / 2012)                                                            10

     Note: See soil improvements required in LAA Design and Drawings.


      4.0 Recommendations:
      4.1 Treatment Facility:
     The on-site treatment facility to service the new dwelling is to be an Advanced Enviro-Septic System (AES). This
     system has a Chief Executive Approval # 15/2019 for Advanced Secondary Effluent. The Person Equivalent (PE) for
     this system is to be no less than 5.

     A new min 4450lt all purpose septic tank is to be installed and must comply with AS/NZS:1546. The position of the
     septic tank on the site plan is indicative.

     All wastewater from the new dwelling is to be directed to the new septic tank then to the AES bed.

     The Land Application Area is to be an Advanced Enviro-Septic Infiltration Bed of 60m2.




      5.0 Design Calculation
      The serviceable life of the Land Application Area will be compromised if the design flow is exceeded. Any
      proposed changes to the position of the Land Application Area, System Type or House Design will require a
      reassessment of this site. For our calculations we have assessed the design flow as follows:

                                                     Design Calculation
         DLR (mm/d) (secondary quality effluent)                                                     10
         Hydraulic load (lt/day/person) Tank Water / 3 bedrooms                                     120
         Design Flow Q (lt/day)   PE: 5                                                             600
         Design sizing calculation                                                           L = Q /(DLRxW)
                                                                                                = (600 / 10)
         Disposal area A+B (square metres) AS/NZS1547:2012                                         60m2
         Nominated Configuration (metres) AES System Design Calculations              = 12.6 x 4.76m (L xW) 60m2
         A new min 4450L Septic Tank is required.                                           AES System EP 5




                                                                                 C Copyright Lance Picton 2022 design & content. 3/11