Proposed change below.  The practice of mounded systems is used extensively in certain states.  Various mound configurations will allow for lower cost, less mechanically complex systems and less reliance on disinfection to achieve treatment goals. 

16. The designer shall specify methods and materials that will achieve the performance requirements of this chapter whenever sand, soil, or soil-like material is used to increase the vertical separation.  Sand, soil, or soil-like material may be mounded on ground surface to achieve vertical separation if the site has a minimum of six inches of naturally occurring soil.