This report describes methods that can be used to evaluate the catalytically blown asphalt (CBA) liner in the secondary containment systems at Valdez Marine Terminal and provides recommendations on the most suitable methods for assessment.
The report also describes a statistical method that was developed to compute the total number of defects (holes, cuts, cracks, or other features that fully penetrate the CBA liner and provide a pathway for liquid flow) in a secondary containment liner with a specified degree of statistical confidence based on outcomes from inspection over a portion of the liner. The statistical methodology was also used to demonstrate how much area of liner needs to be inspected to identify the defects in the liner. Charts are provided that can be used to determine the minimum area of evaluation to obtain an assessment of liner defects with an acceptable percentage of missed defects and an acceptable probability of mistake.
Additional details can be found in the article: Electric current can find damage in underground liners