The Ontario Building Code | Construction Requirements
188.8.131.52. Construction Requirements
(1) The treatment unit used in conjunction with a leaching bed constructedas a Type B dispersal bed shall provide an effluent quality that does not exceed the maximum concentrations set out opposite a Level IV treatment unitin columns 2 and 3 of Table 184.108.40.206.
(2) AType B dispersal bed shall be,
(a) rectangular in shape with the long dimension parallel to the site contours,
(c) backfilled with leaching bed fill so as to ensure that, after the leaching bed fill settles, the surface of the leaching bed will not form any depressions.
(4) The effluent shall be distributed over the Type B dispersal bed through a pressurized distribution system having a pressure head of not less than 600 mm when measured to the most distant point from the pump.
(5) The distribution pipes shall,
(a) be self-draining so as to prevent freezing of their contents, and
(b) have orifices of at least 3 mm in diameter, spaced equally along the length of the pipes.
(a) be comprised of washed septic stone, free of fine material, with gradation conforming to Table 220.127.116.11.,
(b) extend not less than 250 mm below the distribution pipe, and
(c) extend not less than 50 mm above the distribution pipe.
(8) The pump chamber shall be sized to provide sufficient storage volume so that the effluent is evenly dosed on an hourly basis over a 24-hour period.
(9) When there is more than one Type B dispersal bed in a leaching bed, the Type B dispersal beds shall be separated by at least 5 m measured from the edge of the stone layers.
(10) A Type B dispersal bed shall not be located closer than the minimum horizontal distances set out in Table 18.104.22.168.B. and these distances shall be increased when required by Sentence 22.214.171.124.(11).