Q-2, r. 22 - Regulation respecting waste water disposal systems for isolated dwellings

Section 39.1.2 Disposition versions

2020-12-03

39.1.2. Construction standards: An above-ground sand-filter bed must be built with a low pressure feed system,

(a)  applying a maximum hydraulic loading rate to the soil at the disposal site that does not exceed the rates in the following tables, based on the hydraulic conductivity or percolation time and the soil characteristics at the disposal site:

Soil characteristics at disposal site			Maximum hydraulic loading rate L/(m2.d)
	Structure		Effluent from a primary treatment system	Effluent from a secondary treatment system
Textural class
	Type	Grade
Silt loam	Prismatic, blocky or granular	Moderate or strong	24	33
		Weak	16	24
Silt, clay loam or silty clay loam	Prismatic, blocky or granular	Moderate or strong	16	24
		Weak	8	12
Sandy clay, silty clay or clay	Prismatic, blocky or granular	Moderate or strong	8	12
			Maximum hydraulic loading rate L/(m2.d)
Hydraulic conductivity (cm/s)		Percolation time (min/cm) treatment system	Effluent from a primary treatment system	Effluent from a secondary
4X10-3 to 4 X10-4		4 to 15	24	33
4X10-4 to 2 X10-4		15 to 25	16	24
2X10-4 to 6 X10-5		25 to 45	8	12

(b)  applying a maximum linear hydraulic loading rate to the soil at the disposal site that does not exceed the rate in the following table based on the soil characteristics and grade at the disposal site:

Soil characteristics at disposal site			Linear hydraulic loading rate L/(m.d)
Textural class	Structure		Grade at disposal site
	Type	Grade	< 5 %	≥ 5 % < 10 %	10 %
Silt loam	Prismatic, blocky or granular	Moderate or strong	41	50	53
		Weak	37	41	50
Silt, clay loam or silty clay loam	Prismatic, blocky or granular	Moderate or strong	42	41	50
		Weak	37	40	42
Sandy clay, silty clay or clay	Prismatic, blocky or granular	Moderate or strong	37	40	42

The above-ground sand-filter bed must also comply with the construction standards set out in subparagraphs d to g.2 of the first paragraph of section 21 and subparagraphs a and b of the second paragraph of that section, subparagraphs a, b, c and f to i of the first paragraph of section 37 and section 39.1, with the necessary modifications.

O.C. 1156-2020, s. 43.