How does a high water table affect the installation of an onsite system?
All absorption trench systems must meet a minimum vertical separation distance to the seasonally high water table of 900 mm from the bottom of the trench. In areas where the water table does not permit the installation of conventional inground absorption trenches, a raised system can be installed. This can be a raised conventional system, or a raised filter bed system. Alternatively, an advanced treatment unit with an area bed could also be installed as some area beds have reduced vertical separation distances.
