There are two types of soil tests that can be accepted, percolation tests or soil morphology evaluations. Usually, soil morphology evaluations are preferred because they provide more information for system design. Check with the local onsite sewage authority to find out what test will be accepted. Soil evaluator lists can be found through links from the Onsite Professionals page. A list of persons who can do percolation tests is available from the Missouri Department of Health and Senior Services or the local authority.