A Soil Test, is the first step for installing a new or replacement Private Onsite Wastewater Treatment System (POWTS). The results of the soil test determine what type of system will be required for each specific site.
The days of boring a hole and utilizing water to rate a soils hydraulic conductivity are behind us. Now soil
tests are performed by digging a hole with a backhoe and analyzing each soil layer by its physical characteristics. Examples of these characteristics are the soil type, structure, consistency, moisture content, and particle size. Once these have been determined, a hydraulic rating is assigned to each layer.
In addition to analyzing the physical characteristics of the soil, each site is evaluated for limiting factors. A limiting factor is a layer of soil that consists of either periodic high ground water or bedrock. For a septic system, three feet of separation is required between the elevation in which effluent water is discharged in the absorption cell and the limiting factor below. If either high ground water or bedrock is found close to the surface, the required three feet of separation may not be feasible and proper treatment of the effluent water will not be obtained before it enters back into the water table.
Once a soil test has been completed,
the septic system plans can be designed. Next the plans must then be reviewed
before a sanitary permit can be issued. A sanitary permit must be obtained
prior to the start of installing a new system. For a conventional system,
each County's Planning and Development Department approves the plans. For
a mound or holding tank, the plans must also be approved by the Wisconsin
State Department of Commerce. For new construction and remodeling, a sanitary
permit must be obtained before a building permit can be issued.