North Central District Health Department
 
 

Rock System Information

The rock system is the most common type of septic system available (septic installers are very familiar with this system). The rock and pipe system operates very easily; the effluent leaves the home to the septic tank where it receives pre-treatment and moves to the first distribution box (if non-pumped system). If the system is an equal flow distribution type then the effluent will go to all the lines at one time spreading the effluent over the entire field allowing for faster absorption. If the system is a hillside distribution type, then the effluent will go to the first box and then the first line. Once the first line fills to the maximum level the effluent will move to the next box and the next line. This will continue until the end of the lines or the effluent is absorbed.

Advantages

  • Can be used on either level or sloping lots.
  • Most common type of septic system.
  • May be used with all types of distribution boxes.
  • Can be curved around hillsides to allow for installation.

Disadvantages

  • Typically uses the most space of all the systems.
  • Requires more topsoil to cover the system then others.
  • Must have a minimal soil depth of 18" for a shallow installation of this type of septic system.