8.0 Introduction

Throughout the municipal wastewater industry, the terms sludge and biosolids are often used interchangeably. However, from a regulatory standpoint, only municipal wastewater treatment sludge (including domestic septage) that meets certain quality criteria specified in the 40 CFR Part 503 rule should be designated as biosolids [42,48]. Sludge generated from municipal wastewater treatment operations that does not meet these criteria and/or domestic septage that contains industrial and/or commercial wastes are not considered biosolids.

Sampling is the first step in developing a database to monitor performance or to control processing within a municipal wastewater treatment plant. Within publicly owned treatment works (POTW), both sludge and biosolids are sampled routinely by treatment plant personnel to verify compliance with regulatory limits as well as to evaluate the effectiveness of the various sludge/biosolids processing operations. This chapter provides descriptions of both the general sludge and biosolids sampling procedures typically employed at POTWs and those specific biosolids sampling requirements mandated by the 40 CFR Part 503 rule. Finally, for the management of biosolids beneficial-use operations, descriptions of the general sampling procedures used to monitor the effects of biosolids land-application operations on environmental quality (including soil and vegetation) are provided.

8.1 General Sampling of Sludge and Biosolids

Accurate characterization of sludge/biosolids is required to identify and isolate operational problems at the POTW as well as to signal potential limitations to the use or disposal of biosolids. To the extent practicable, the POTW should have a sludge/biosolids sampling program that adequately addresses the random...