ASTM D6766-20A

1.1 This test method covers laboratory measurement of both flux and hydraulic conductivity (also referred to as coefficient of permeability) of geosynthetic clay liner (GCL) specimens permeated with chemical solutions and leachates utilizing a flexible wall permeameter. For test measurement of index hydraulic properties of geosynthetic clay liners, refer to Test Method D5887/D5887M. For hydraulic conductivity compatibility of soils with aqueous chemical solutions and leachates, refer to Test Method D7100.

1.2 This test method may be utilized with GCL specimens that have a hydraulic conductivity less than or equal to 1 × 10^–5 m/s (1 × 10^–3 cm/s).

1.3 This test method is applicable to GCL products having geotextile backing(s). It is not applicable to GCL products with geomembrane backing(s), geofilm backing(s), or polymer coating backing(s).

1.4 This test method allows the requester to evaluate the hydraulic properties of a GCL with site-specific or laboratory-prepared solution under different test conditions; thus, the test method also may be used to check performance or conformance, or both.

1.5 The values stated in SI units are to be regarded as the standard, unless other units are specifically given. By tradition in U.S. practice, hydraulic conductivity is reported in centimeters per second, although the common SI units for hydraulic conductivity are meters per second.

1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.