Mounded dispersal areas required in New Hampshire where seasonal high water tables are higher than 46” or ledge is higher than 52” below the surface.  Currently, the State rules allow Advanced Presby Enviro dispersal  pipe to be installed as little as 24” above the seasonal high water table. Other dispersal piping types are required by rules to be higher above the seasonal high water table.  Therefore, most systems designed and constructed in NH today are using Advanced Presby dispersal piping.  Hogg Hill Design is a licensed Presby designer in NH and VT, and designs using Advanced Presby or the dispersal piping, or unit, of your choice.  We can discuss the pro and cons of various systems as applicable to your application.  

Advanced Presby Mound - Sloping