This is the last in a series of stories highlighting design principles that will help properly maintained onsite systems last indefinitely.Knowing the type of soil at a system installation site is an absolute must. We are always nervous when we hear statements like: “I do not need to know soils; I just need to be able to follow the plan from the designer.” These comments usually come in situations where the designer and the site evaluator are different people. Upon further questioning, we typically find the site evaluator gives the information to the designer and the designer has never visited
