06/1354 - Response to Information Request [As Published] · 132006.1354

Due to the proximity of adjacent lots, it is recommended that treatment of effluent
be to a secondary level; however disposal area size has been calculated using primary
effluent parameters (worst case scenario).

3. Daily Flow Allowances

Population equivalent for 4 bedroom homes is 6 EP (ASNZ1547:2000).
Water use for households with standard fixtures, using water supplied by onsite
Rainwater tanks is 140 L/person/day (AS/NZ 1547;2000).

Daily Design Flow (Q) = 6EP x 140 Lip/d
= 840 litres/day

4. Investigation Works

The permeability tests were carried out by Bowler Geotechnical, using a test hole
100mm in diameter and 450mm deep, according to the method set out in appendix 4.1F
of AS1547-2000 ‘On site domestic wastewater management’ (Constant Head Method).

The subsurface profile of the site has been established previously by Bowler
Geotechnical , consisting generally of a sand layers to depths of 1.5m and classification
as Category 1 (Gravels and Sands) or Category 2 (Sandy Loams) as per AS/1547:2000
(see Report 3436 C). At the particular test hole locations Bowler Geotechnical
correspondance of 20 March 2007 refers to the soil encountered as Sand (massive) and
would be considered to be Category 1.

4.1 Permeability Test Results
Lot 8 (Location 2*) : Ksat = 3.79m/day

*Note that the location of this test was in a different position to a previous Test
HoleA approximately 30m S-W which recorded a low permeability, per Bowler Job
Report # 3436.

Lot 9 (Location 1) : Ksat = 3.41m/day

5. Design Loading Rate

The lower indicative permeability for Lots 8 and 9 is Ksat 3.4 m/day, the assigned
Design load rate (DLR) for that lot is selected as 20 mm/day; obtained from Table 4.2A1
in ASNZ1547-2000, which shows a range of 20mm/day to 35mm/day for the given
parameters.