15A NCAC 18E .0903      BED SYSTEMS

(a)  This Rule shall apply to bed systems receiving DSE.

(b)  Bed systems shall be limited to 600 gpd unless approved for a greater DDF in accordance with a PIA Approval.

(c)  Sites for bed systems shall meet the following criteria:

(1)           soil texture is Group I, II, or III; and

(2)           design options for the site are limited by topography or available space.

(d)  The number of square feet of infiltrative surface area required shall be increased by 50 percent over that required for a trench system as calculated in accordance with Rule .0901(d) of this Section.

(e)  In addition to the installation requirements set forth in Rule .0901(g) of this Section, the following shall apply:

(1)           the bottom of the bed shall be excavated level, plus or minus one-half inch, in all directions;

(2)           laterals shall be one and one-half feet from the side of the bed;

(3)           laterals shall be placed on three-foot centers;

(4)           aggregate used shall comply with the requirements of Rule .0902(b)(4) of this Section;

(5)           products approved under Section .1700 of this Subchapter shall be installed in accordance with their PIA Approval;

(6)           the gravel surface shall be covered by an approved geo-textile fabric capable of preventing the downward movement of soil particles while allowing the movement of liquids and gases; and

(7)           when pressure dispersal is used, the lateral design criteria shall meet the minimum requirements of Rules .0907(e) or .0908(d) of this Section or in accordance with a PIA Approval.

History Note:        Authority G.S. 130A-335(e), (f), and (f1);

Eff. January 1, 2024.