The Ontario Building Code | Length of Distribution Pipe
8.7.3.1. Length of Distribution pipe
(1) The total length of distribution pipeshall,
(a) not be less than 30 m when constructed as a shallow buried trench, or
(b) not be less than 40 m for any other absorption trench.
(2) Except as provided in Sentences (1), (3), and (4) every leaching bed constructed by means of absorption trenches shall have a total length of distribution pipe not less than the value determined by the formula,
where,
L = total length of distribution pipe in metres,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.
(3) Except as provided in Sentence (1), where a leaching bed receives effluent from a Level II, Level III or Level IV treatment unit as described in Table 8.6.2.2., the leaching bed may have a total length of distribution pipe not less than the value determined by the formula,
where,
L = total length of distribution pipe in metres,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.
(4) Except as provided in Sentence (1), where the leaching bed is constructed as a shallow buried trench, the total length of the distribution pipe shall not be less than the value determined by Table 8.7.3.1.
Table 8.7.3.1.
Length of Distribution pipe in Shallow Buried Trench
Forming Part of Sentence 8.7.3.1.(4)
| Item | Column 1 Percolation Time, (T) of soil, min | Column 2 Length of Distribution pipe, m |
| 1. | 1 < T ≤ 20 | Q/75 |
| 2. | 20 < T ≤ 50 | Q/50 |
| 3. | 50 < T < 125 | Q/30 |
where,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.
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. 60)
8.7.3.1A. Length of Leaching Chamber
(1) The total length of leaching chamber shall,
(a) not be less than 30 m when constructed as a shallow buried trench, or
(b) not be less than 40 m for any other absorption trench.
(2) Except as provided in Sentences (1) and (3), the total length of leaching chamber shall not be less than the value determined by the formula,
L = QT/200, for a Type I leaching chamber, or
L = QT/300, for a Type II leaching chamber,
where,
L = total length of leaching chamber in metres,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.
(3) When a treatment unit described in Article 8.6.2.2. is used in conjunction with a leaching chamber, the total length of leaching chamber shall not be less than the value determined by the formula,
L = QT/300
where,
L = total length of leaching chamber in metres,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.
(4) Except as provided in Sentence (1), where the leaching bed is constructed as a shallow buried trench, the total length of leaching chamber shall not be less than the value determined by Table 8.7.3.1A.
Table 8.7.3.1A.
Length of Leaching Chamber in Shallow Buried Trench
Forming Part of Sentence 8.7.3.1A.(4)
| Item | Column 1 Percolation Time, (T) of soil, min | Column 2 Length of Leaching Chamber, m |
| 1. | 1 < T ≤ 20 | Q/75 |
| 2. | 20 < T ≤ 50 | Q/50 |
| 3. | 50 < T < 125 | Q/50 |
where,
Q = the total daily design sanitary sewage flow in litres, and
T = the design percolation time.