Skip to Main Content

DEQ Title, click to go to DEQ home page


A soil test must be performed prior to the installation of a subsurface on-site sewage system. There are two types of soil tests used to determine the characteristics of the soil on your property, the soil percolation test and the soil profile. Each of the tests requires three test holes to be dug or drilled in the location of the proposed on-site system.

Percolation tests may only be used to identify suitable areas for the conventional subsurface system, lagoon, or aerobic system with spray irrigation. These tests measure the drop of water within a specific time period. Test holes are presoaked with water for a minimum of four hours, the water level is adjusted to a depth of 10 inches and the percolation rate is recorded. The on-site sewage disposal system is designed based on the percolation rate (inches of water dropped per minute).


Individual and Small Public Onsite Sewage Treatment Systems Fees

Request a Soil Test

Soil Profilers

Soil Profiler Application Packet (PDF)


Soil profiles, a more scientific test, evaluate three critical aspects of the soil that may have the potential to cause an on-site sewage system to malfunction.
· The texture of soil in area of the proposed on-site sewage system
· The presence or absence of water saturated soils
· The depth to an impervious soil layer (rock)
All three parameters are used to design the most appropriate on-site system for your property.

Photos to the left and below show that defining the soil has three basic steps, augering, soil texturing and classifying the soil






In addition to the soil test, other factors need to be considered in determining the appropriate on-site system for your home.
· The general topography of your property,
· The number of bedrooms in your residence,
· Potential water usage
· Future land use of the property

For additional information on soil tests, please contact your local DEQ office or call 405/702-6100.

For additional on-line information on soil, please click the following link to the OSU-DEQ Soil Book.



Back to On-site sewage page