GCLs must be properly manufactured in a manner consistent with a minimum level of quality control as determined by in-house testing of the final product. This practice suggests the types of tests, the methods of the testing and the minimum testing frequencies.

It should be clearly recognized that manufacturers may perform additional tests or at greater frequency than required in this practice, or both. In this case, the manufacturer's quality control plan will then take precedence over this practice. The quoted tests and test methods in Table 1 must appear in the QC plan and the QC report.

It should also be recognized that purchasers and installers of GCLs may require additional tests or at a great frequency than called for in this practice, or both. The organization(s) producing such project specific specification or quality assurance plan should recognize that such requirements are beyond the current state of the practice. If such a request is made by purchasers or installers, they should clearly communicate the requirements to the manufacturer or supplier during the contract decisions in order that disputes do not arise at a subsequent time.

TABLE 1 Minimum Types of Tests and Their Frequencies for the QC of GCLs

^A The tests on the bentonite are to be performed on the as-received material before fabrication into the GCL product.

^B Cert letter from component manufacturer or QA from GCL manufacturer, or both. Cert letters must arrive and be checked before the components are used for the GCL production.

^C For geofilms, Test Method D882 may be more appropriate.

^D Components from finished GCL product should not be separated and tested, because the production process may alter the properties of the components.

^E Dried bentonite should be defined as 0 % moisture content.

^F Only for information.

^G This test may not be applicable for geomembrane-backed GCLs.

^H The last 20 values to be reported should end at the production date of the supplied GCL. If the manufacturer has more production facilities or production lines, or both, the tests must be performed and reported for each line.