Naturally High Water Table refers to the drainage field / soakaway being under the natural water table.  This can often be the cause for septic tank soakaway systems failing during winter months only.  When a drainage field / soakaway is operating underneath the natural water table the septic tank, soakaway and foul drainage pipework will be at the same level as the surrounding water table and as a result the flooding within the system can be moderate or severe.

Problems with septic tank systems operating in high water table areas can be overcome by installing a Mantair septic tank conversion system.