The Ontario Building Code | Distribution Pipe
8.7.3.3. Distribution pipe
(1) Except for a shallow buried trench, the distribution pipe used in the constructionof a leaching bed shall be,
(a) not less than 3 in. trade size for gravity flow systems,
(b) installed with a uniform downward slope from the inlet with a drop of not less than 30 mm and not more than 50 mm for each 10 m of distribution pipe for gravity flow systems, and
(c) installed within a layer of stone conforming to Sentence (5).
(2) Prior to backfilling, the stone layer required by Clause (1)(c) shall be protected in such a manner so as to prevent soilor leaching bed fillfrom entering the stone by completely covering it with,
(a) untreated building paper, or
(b) a permeable geo-textile fabric.
(3) Every pressurized distribution pipeshall be self-draining so as to prevent freezing of its contents.
(4) Every pressurized distribution pipeshall,
(a) be not less than 1 in. trade size, and
(b) have orifices of at least 3 mm in diameter, spaced equally along the length of the pipe.
Note: On January 1, 2018, Clause 8.7.3.3.(4)(b) of Division B of the Regulation is amended by adding "to provide even distribution of the effluent" at the end. (See: O. Reg. 139/17, s. 62 (1))
(5) The stone layer required by Clause (1)(c) shall,
(a) be comprised of washed septic stone, free of fine material, with gradation conforming to Table 8.7.3.3.,
(b) be not less than 500 mm in width,
(c) extend not less than 150 mm below the distribution pipe, and
(d) extend not less than 50 mm above the distribution pipe.
Table 8.7.3.3.
Gradation of Septic stone
Forming Part of Sentences 8.7.3.3.(5) and 8.7.8.2.(6)
| Item | Column 1 Particle Size | Column 2 Percent Passing |
| 1. | 53 mm | 100 |
| 2. | 19 mm | 0-5 |
| 3. | 75 µm | 0-1 |
Note: On January 1, 2018, Article 8.7.3.3. of Division B of the Regulation is amended by adding the following Sentence: (See: O. Reg. 139/17, s. 62 (2))
(6) This Article does not apply to a distribution pipe within a leaching chamber.
Note: On January 1, 2018, Subsection 8.7.3. of Division B of the Regulation is amended by adding the following Article: (See: O. Reg. 139/17, s. 63)
8.7.3.4. Leaching Chamber
(1) Prior to backfilling, the leaching chamber shall be,
(a) installed level over the length of the absorption trench,
(b) securely connected together, section to section,
(c) free of structural damage, uncut and used full length,
(d) equipped with end caps installed on both ends,
(e) equipped with an integrated splash plate at the inlet end of each line of leaching chamber, to prevent soil scouring, and
(f) protected in such a manner so as to prevent soil or leaching bed fill from entering the leaching chamber.
(2) Except for a shallow buried trench, the distribution pipe within a leaching chamber shall be not less than 3 in. trade size for dosed systems.
(3) Every pressurized distribution pipe within a leaching chamber shall,
(a) extend over the entire length of the leaching chamber,
(b) be not less than 1½ in. trade size,
(c) have orifices of at least 6 mm in diameter, spaced equally along the length of the pipe to provide even distribution of the effluent,
(d) be supported,
(e) be self-draining so as to prevent freezing of its contents, and
(f) have cleanouts installed at the downstream end of each line of leaching chamber to allow for servicing of the system.
8.7.4. Fill Based Absorption Trenches