HAR §11-62-34. (F) The distribution line shall be carefully placed on the bedding at a uniform slope and covered with at least two inches of gravel or stone

(G) The ends of the distribution lines shall be capped or plugged. (b) Deep absorption trenches. Deep absorption trenches may be considered where the depth of suitable soil is insufficient to permit the installation of a conventional trench system due to the presence of a limiting layer more than two feet in depth which overlies suitable soils of sufficient thickness. Requirements for location, design, slope, material, construction, and dosing system design contained in subsection (a) shall apply to deep absorption trenches except for depth of construction. In addition, the following design considerations shall apply: (1) The site evaluation procedure shall include soil profile observations of at least three soil observation pits constructed to a minimum depth of three feet below the proposed trench bottom. Monitoring to establish depth to seasonal soil saturation or high groundwater may be considered; (2) Deep absorption trenches shall be constructed at least one foot into the suitable soil; and (3) The distribution piping in deep absorption trenches shall be installed with the invert of the piping at a depth of not more than thirty inches. Gravel or crushed stone shall be placed from the bottom of the trench excavation to a point two inches above the top of the distribution piping. (c) Absorption beds. (1) Location. (A) Absorption beds shall be located in accordance with section 11-62-32. (B) Absorption beds shall not be constructed in soils with a percolation rate slower than sixty minutes per inch or where rapid percolation may result 62-62 B176 §11-62-34 in contamination of water-bearing formations or surface waters. (C) Absorption beds shall be located on the property to maximize the vertical separation distance from the bottom of the absorption bed to the seasonal high groundwater level, bedrock, or other Limiting layer, but under no circumstance shall the vertical separation be less than three feet. The director may require a greater vertical separation where water-bearing formations are in danger of contamination. (D) Absorption beds shall not be constructed in unstabilized fill. (2) Design. (A) The minimum area for any absorption bed system shall be based upon a flow of 200 gallons per bedroom per day and in accordance with Appendix D, Table III dated July 1, 2014 and located at the end of this chapter. (B) The absorption area shall be computed using the bottom area of the absorption bed. (C) Each soil absorption bed system shall have a minimum of two distribution lines. (D) If more than one absorption bed is designed, each absorption bed shall be equal in area. (E) The maximum length of any distribution line shall be one hundred feet. (F) Distribution lines within an absorption bed shall be uniformly spaced no more than six nor less than four feet apart. (G) Distribution lines within an absorption bed shall be placed no more than three feet nor less than eighteen inches from the sidewall of the bed. 62-63 3176