The present invention is directed to a sludge collector for use with a circular clarifier. After a call blast event has been determined to have occurred during a trunk group’s calling hour, the method uses current and history trunk group traffic statistics to determine the number of \u201cnormal\u201d calls that were blocked during a calling hour. According to another aspect of the present disclosure, the methods to eliminate voids include formation of an opening on a semiconductor structure, formation of a diffusion barrier layer, deposition of a metal into the opening, preamorphization of the metal using a contact with a plasma, and formation of a conductivity facilitating layer. Then, a decision is made whether to allow capture of the object based upon whether the selected indicia includes a globally-unique identifier and is secure. The anchor additional thread is configured to engage either the friable material or, additionally, to firmly engage the semi-rigid material.