The following points must be considered when completing a site layout plan.

1 Before a percolation test is commenced, the proposed location and invert level of the percolation area should be established.


2 To achieve this, the levels for the proposed driveway and footpaths should be established.


3 The footpaths and manholes around the house define the up-line invert level of the waste water system.


4 Establishing footpath and floor levels will also help in evaluating the optimum height of the house in terms of impact on local landscape.


5 Unique contours/features of the site should be evaluated when positioning the house to minimize excavation and maximise natural contours.


6 The previous considerations will impact on deciding where to locate the treatment system and percolation area.


7 The invert levels from the footpath manhole can be calculated to provide the invert level of the percolation area.


8 This invert level will determine the location and depth in which the percolation test should be carried out.