ABSTRACT
Sludge quantity and quality are the two key factors in any sludge reuse program. The first task of a beneficial reuse program is to quantify these variables thoroughly. Sludge which is land applied must comply with federal and state regulations that restrict the levels of contaminants in order to protect the public health and the environment. The characteristics of sludge depend on the origin, the amount of aging that has taken place, and the type of processing the sludge has received. Sludge from primary sedimentation tanks is usually gray and slimy and, in most cases, smells awful. It can be readily digested under suitable conditions. Wastewater treatment plants are enormously capital-intensive facilities that last for generations. The influent flow at a treatment plant carries a wide range of debris along with the wastewater solids. Preliminary screening protects the plant equipment from debris.
