39.1.1. Installation conditions in structured clay or silty clay soils: A primary or secondary treatment system may also be connected to an above-ground sand-filter bed in the following conditions:(a) a soil absorption field or a seepage bed cannot be built because it is impossible to comply with section 17 or 26;
(b) using the correlation method in Schedule 1, the soil at the disposal site is impermeable solely because its texture is in the impermeable zone and, based on the hydraulic conductivity test or the percolation time test, the soil at the disposal site is permeable or low permeability soil. For the determination of the level of soil permeability, the result obtained by the correlation method must, however, be excluded;
(c) the soil at the disposal site,i. according to its textural class, is structured as described in the following table:Textural class of the soil | Required soil structure |
| Type | Grade |
Silt, silt loam, clay loam or silty clay loam | Prismatic, blocky or granular | Weak |
Moderate or strong |
Sandy clay, silty clay or clay | Prismatic, blocky or granular | Moderate or strong |
ii. in a moist state has a consistence that is loose, very friable, friable or firm and is not in a cementation class; and
iii. is not in the smectitic mineral class; and
(d) the disposal site complies with the conditions described in paragraphs b and c of section 36.