Mound System

Another system suited for sites with shallow soils is a sand mound. A mound is a drainfield raised above the natural soil surface with a sand fill material. Within the sand fill is a gravel bed with a network of pressurized pipes. Septic tank effluent is pumped through the pipes in controlled doses to insure uniform distribution throughout the bed. Treatment of the effluent occurs as it moves downward through the sand and directly into the natural soil beneath.

They are also used when you have rocky soil because the effluent will run right through it without being treated.  Conversely, if the soil is too slow mounds can be used because a large portion of the effluent is returned to the atmosphere via evaporation so a mound will make up for slow soils.   

Sand mound septic systems use 2 tanks...this first tank is used as a normal tank (for settling of the solids) and the second tank has a pump in it that when the water level reaches a certain point or with a timer, the pump kicks on and pushes the effluent to the  mound...because of the small pipe and holes, the effluent is distributed (under pressure) evenly throughout the mound.


Services We Provide

Service Area

  • Battle Ground, WA
  • Brush Prairie, WA
  • Camas, WA
  • Hazel Dell, WA
  • Hockinson, WA
  • La Center, WA
  • Meadow Glade, WA
  • Mill Plain, WA
  • Ridgefield, WA
  • Vancouver, WA
  • Washougal, WA
  • Woodland, WA
  • Yacolt, WA