Former Construction and Siting Protocol
NSTS-07b Compacted Soil Liners

For the Regulation made under the Nutrient Management Act, 2002.
(This protocol no longer exists under O. Reg. 267/03.)

| Table of Contents | NSTS-01 | NSTS-02 | NSTS-03 | NSTS-04 | NSTS-05 | NSTS-06 | NSTS-07a |
| NSTS-07b | NSTS-08 | NSTS-09 |

NSTS-07b Compacted Soil Liners

Section 1 - Purpose and Scope
Section 2 - Material Suitability
Section 3 - Materials and Testing
Section 4 - Construction Equipment
Section 5 - Compacted Soil Liner Construction
Section 6 - References

Section 1- Purpose and Scope

1.1 Purpose of the Standard - This protocol provides the professional engineer with specifications and construction procedures for the design of compacted soil liners.

1.2 Requirement for a Compacted Soil Liner - compacted soil liners may be used to line liquid nutrient storage facilities where a liner is required by the Regulation or NSTS-03; Site Characterization.

1.3 Definition of a Compacted Soil Liner - A compacted soil liner is a seepage barrier constructed of a cohesive soil that is compacted to increase its dry bulk density and homogeneity, reduce porosity and decrease soil permeability. Within the earthen nutrient storage facility, the compacted soil liner is designed to impede seepage of the liquid nutrient into the subsurface below or adjacent to the facility.

1.4 Definitions - Compacted Soil Liner - for the purpose of protocols NSTS-06 and NSTS-07 the term "compacted soil liner" means; a hydraulically secure soil that is compacted to 95% of modified Proctor density at the optimum moisture content to meet a maximum saturated hydraulic conductivity of not more than 1 x 10^-9 metres per second (as per ASTM D1557-02).

1.5 Scope of the Standard - For a compacted soil liner to function properly, it must be designed and constructed according to strict engineering standards and specifications. This standard describes the design criteria, methods of construction, and quality assurance and control procedures required for the acceptable construction of these liners.

Section 2 - Material Suitability

2.1 Part VIII of the Regulation requires that the professionalengineer be responsible to ensure that the required tests are carried out to accurately characterize the material used to construct the compacted soil liner. The professional engineer must use a laboratory, capable of proving the suitability of the materials used in the soil liner and to ensure that they follow the specifications as outlined in the Regulation.

Section 3 - Materials and Testing

3.1 If the distribution of the particle size classes and the Atterberg limits fall within the acceptable ranges given in Subsection 3.1.1. and 3.1.2, the material is considered acceptable for compacted soil liner construction without the need for additional laboratory testing providing it is installed using the recommended methods and equipment as described in Sections 4 and 5. The use of acceptable materials with the appropriate construction methods and equipment are expected to produce compacted soil liners with hydraulic conductivities of 1 x 10^-9 metres/second or less.

3.1.1 Acceptable Particle Size Ranges (by weight):

• Percent Fines ; ≥ 50 %;
• Clay Content ; ≥ 20 %;
• Sand Content ; ≤ 45 %;
• Gravel Content; ≤ 50%; and

3.1.2 Acceptable Atterberg Limits:
· Plasticity Index (PI): 11% ≤ PI ≤ 30 %.
· Liquid Limit (LL): 30% ≤ LL ≤ 60 %

3.2 Where the materials used to construct the compacted soil liner do not meet the specifications set out in subsections 3.1.1 and 3.1.2 the materials should be laboratory tested and a liner design and construction method specified to ensure that the liner will meet a final maximum saturated hydraulic conductivity of 1 x 10-9 metres per second.

3.3 In situ testing - Moisture and density tests should be performed on the liner during and after construction to ensure that the liner meets the required design specifications.

Section 4 -Construction Equipment

4.1 Recommended Equipment -The recommended compaction equipment for the construction of a compacted soil liner is the Sheepsfoot Roller Compactor. Rollers should meet the following criteria:

4.1.1 Soil Contact Pressures - The compaction equipment or rollers should be ballasted to attain soil contact pressures of at least 2400 kPa.

4.1.2 Tamping Feet Requirement -The tamping feet should be 200 mm to 250 mm in length from the cylindrical surface of the roller. The tamping feet should have a face area between 4500 and 6000 mm² . The compactor feet should be spaced to provide at least 4 tamping feet for each 0.25 m² of cylindrical surface.

4.1.3 Other compaction equipment may be used at the discretion of the professional engineer.

Section 5 - Compacted Soil Liner Construction

5.1 Part VIII of the Regulation requires that the minimum thickness of the completed compacted soil liner shall be 0.9 m on the sloping sidewalls and 0.6 m on the bottom of the storage.

5.2 The inside side slopes of the earthen nutrient storage facility should be no steeper than 1:2 (rise:run). The professional engineer may recommend flatter slopes or specify the use of procedures or equipment to ensure proper compaction of the liner.

5.3 In accordance with Part VIII of the Regulation, the compacted soil liner on the sidewall shall consist of six - 150 mm layers. The layer on the bottom shall consist of four 150 mm layers. To allow proper sealing between layers, the interface surface of lower layers must be properly disked or scarified, before placement of subsequent layers of material.

5.4 Part VIII of the Regulation requires that the soil liner shall be compacted at least 95% of modified Proctor maximum dry density as determined for this soil at a specified optimum water content. Construction which follows ASTM D1557-02 should be able to meet this criteria.

5.5 All rocks and stones of significant size, roots and other organic debris should to be removed from liner material prior to compaction.

5.6 Excavation and compaction should be completed during periods when soil temperatures are above freezing. Each compacted lift should be protected from drying out to prevent cracking due to shrinkage.

5.7 The overlap between equipment passes should not be less than 10 % of the width of the equipment being used to ensure lateral bonding between placed materials.

Section 6 - References

Construction and Siting Protocol Standard NSTS-01; Engineering and Inspection
Construction and Siting Protocol Standard NSTS-03; Site Characterization
Construction and Siting Protocol Standard NSTS-06; Earthen Nutrient Storage Facilities
ASTM D1557-02 Standard Test Method for Laboratory Compaction Characteristics of Soil using Modified Effort

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