(a) PPBPS utilize both horizontal and vertical air chambers in a 16-inch PPBPS and are constructed to promote downline and horizontal distribution of effluent. PPBPS systems shall only be used with DSE.

(b) The requirements of Rule .0901 of this Section shall apply to PPBPS systems except as follows:

• (1) the LTAR determined in accordance with Rule .0901(c) of this Section shall not exceed 0.8 gpd/ft2; and

• (2) to calculate the minimum trench length in accordance with Rule .0901(d) of this Section, an equivalent trench width of six feet shall be used.

(c) In addition to the requirements set forth in Rule .0901(g) of this Section, PPBPS system installations shall comply with the following and the manufacturer's specifications:

• (1) PPBPS trenches shall be located a minimum of eight feet on center or three times the trench width.

• (2) trench sidewalls shall be raked in Group IV soils.

(d) When used in bed, fill, or sand lined trench systems, PPBPS shall use the equivalent trench width of six feet to calculate the minimum trench length required. required, unless otherwise instructed by the manufacturer on a case-by-case basis.

(e) When used in sand lined trench systems, PPBPS shall use the equivalent trench width of three feet to calculate the minimum trench length required.

History Note: Authority G.S. 130A-335(e) and (f); S.L. 2023-63, s.16.