A proposed methodology for an accurate estimation of the total amount of materials recycled

摘要

A comprehensive study of the recycling infrastructure in Illinois is underway. One of the objectives of this study is the development of a methodology for an accurate estimation of the amount of total materials recycled (TMR). Based on the collected information from 230 recycling facilities and data from previous surveys, it was found that responses from a small number of critical facilities (CF) are essential for an accurate estimation of the amount of TMR. This finding was utilized to develop a sample design which has the potential to yield an accurate estimate of the TMR. The components of this design are systematic sampling of the CF and random sampling of the remaining ones. The proposed methodology has been applied to a selected sample of recycling facilities in Illinois for which detailed information was available. This application yielded an accurate estimate with a less than 1% difference from the actual TMR. In addition, to achieve this favorable result less than 15% of the total number of recycling facilities were included in the CF sub-population.