Section 410IAC6-8.3-89. Elevated sand mound on-site sewage systems: placement of the soil material and final grade

   (a) If the ground surface along the perimeter of the INDOT Specification 23 sand was not tilled during preparation of the elevated sand mound site, the perimeter shall be prepared by tilling in accordance with the requirements of section 86 of this rule.

  (b) The soil material cover shall:

(1) have a texture other than sand or loamy sand;

(2) be capable of sustaining plant growth; and

(3) be placed on the INDOT Specification 23 sand without causing compacted soil material.

  (c) Prior to placement of the soil cover material, the surface of the INDOT Specification 23 sand shall be prepared by:

(1) maintaining a minimum grade of at least three-to-one (3:1); and

(2) preparing the surface of the INDOT Specification 23 sand so that it is smooth and free of ruts and depressions.

  (d) The aggregate and sand of the elevated sand mound shall be covered with a minimum of twelve (12) inches of soil material. An additional six (6) inches of that soil material, for a total of eighteen (18) inches, shall be placed over the center line of the long axis of the aggregate bed and crowned to promote surface runoff away from the elevated sand mound.

  (e) Soil material shall be placed on the tilled portion of the sand perimeter and graded according to the requirements of subsection (f).

  (f) The soil material cover shall have a minimum final grade on all sides of three-to-one (3:1).

  (g) The elevated sand mound shall be seeded or sodded with grasses adapted to the area. If seeded, the elevated sand mound shall be protected by a cover of straw, burlap, or some other biodegradable material that will protect it against erosion. (Indiana State Department of Health; 410 IAC 6-8.3-89; filed Oct 19, 2012, 2:06 p.m.: 20121114-IR-410120156FRA)