87.19. Installation conditions: A leaching field may be built where the following conditions are met:(a) the grade of the disposal site is less than 30%;
(b) the leaching field complies with the location standards in section 7.2;
(c) the disposal site consists of high permeability soil and the bedrock, underground water or any layer of impermeable, low permeability or permeable soil is at least 60 cm below the surface of the disposal site, or of permeable soil or low permeability soil and the bedrock, underground water or any layer of impermeable soil is at least 30 cm below the surface of the disposal site.