The most satisfactory treatment and disposal method of domestic wastewater is through a municipal sewage system. Where municipal systems are available, on-site systems are discouraged. In rural areas, however, some type of on-site system for treatment and disposal of wastewater may be the only option. Primarily, two types of private on-site treatment systems are used in Kansas: septic tank-lateral systems (septic systems) and wastewater stabilization ponds (lagoons). The septic system is the most common form of on-site wastewater treatment, and it is the most desirable on-site system to use if soil conditions are suitable. Since the septic tank and laterals are completely covered with soil, the system is not visible and odor is nonexistent, as long as wastewater does not surface. In areas with restrictive permeability, high clay subsoil (i.e. slow percolation rates), or shallow bedrock where adequate area is not available, it can be difficult and expensive to build lateral fields that will effectively treat and absorb wastewater. Lagoons should be considered for domestic wastewater treatment in these areas.