Sub-Surface Seepage System

The most common private sewage system installed nationwide is the septic tank followed by a subsurface seepage system. Since this system depends on the absorption properties of the soil, it must be installed in soils which drain well and are not affected by a seasonal high water table. To determine the suitability of the soil, a percolation test must be conducted prior to installing the system. Once the test results are known, it can be determined if a field will function properly and if so, how much field is necessary. If your percolation tests do not pass, then one of the following types of alternative systems must be considered.


  • First choice of system for soil that will absorb septic tank discharge
  • Usually lower installation cost
  • Low maintenance, simply pump septic tank every 2-5 years



  • Requires soil that will absorb septic tank effluent (clay soils unsuitable)
  • Extreme high water tables interfere with proper function