H 601.0 Disposal Fields
Exception: Listed or approved plastic leaching chambers and bundled expanded polystyrene synthetic aggregate units shall be permitted to be used in lieu of pipe and filter material. Chamber and bundled expanded polystyrene synthetic aggregate unit installations shall follow the rules for disposal fields, where applicable, and shall be in accordance with the manufacturer's instructions.
TABLE H 601.9
GENERAL DISPOSAL FIELD REQUIREMENTS
|Number of drain lines per field||1||-|
|Length of each line||-||100 feet|
|Bottom width of trench||18 inches||36 inches|
|Spacing of lines, center-to-center||6 feet||-|
|Depth of earth cover of lines (preferred 18 inches)||12 inches||-|
|Grade of lines||level||3 inches per 100 feet|
|Filter material under drain lines||12 inches||-|
|Filter material over drain lines||2 inches||-|
For SI units: l inch = 25.4 mm, l foot = 304.8 mm, l inch per foot = 83.3 mm/m
Minimum spacing between trenches or leaching beds shall be not less than 4 feet (1219 mm) plus 2 feet (610 mm) for each additional foot (305 mm) of depth more than 1 foot (305 mm) below the bottom of the drain line. Distribution drain lines in leaching beds shall be not more than 6 feet (1829 mm) apart on centers, and no part of the perimeter of the leaching bed shall exceed 3 feet (914 mm) from a distribution drain line. Disposal fields, trenches, and leaching beds shall not be paved over or covered by concrete or a material that is capable of reducing or inhibiting a possible evaporation of sewer effluent.
H 601.10 Joints. Where necessary on sloping ground to prevent excessive line slope, leach lines or leach beds shall be stepped. The lines between each horizontal section shall be made with watertight joints and shall be designed, so each horizontal leaching trench or bed shall be utilized to the maximum capacity before the effluent shall pass to the next lower leach line or bed. The lines between each horizontal leaching section shall be made with approved watertight joints and installed on the natural or unfilled ground.