How to interpret ASTM index tests and performance parameters for rolled erosion control products

While engineers, hydrologists, and other similarly trained technical people have an understanding of ASTM procedures and utilization of various test values, many managers and project owners do not understand the relevance of test values to anticipated performance of erosion control products. This paper is an effort to assist people in understanding how some Index and Performance parameters can be used in selecting an appropriate erosion control product. Some manufacturers include in their literature detailed information about the result of ASTM tests performed on their products. References to "performance standards" and "performance capabilities" are found in many brochures, mass mail documents, and in discussions with sales representatives. Values for tensile strength, elongation, flexibility, flow velocity, permissible shear stress, absorptive capacity, resiliency, tear resistance, Manning's "N", and the "C" Factor are commonly found in product promotional literature. What do these values mean to someone who is trying to pick an appropriate material for their project? What is the difference between index parameters and performance parameters? How do the numeric values of the "parameters" translate into real-world results? RECP (rolled erosion control product) manufacturers encourage specifiers and designers to use the test data currently available to assist in selecting the Best Management Practice for their individual projects. The product specified should be able to withstand the stress of installation, provide adequate time for vegetation to become established, control soil loss, and promote the establishment of vegetation. Permanent erosion control is best achieved through permanent vegetation.