Review of Pretreatment Permit Limits and Compliance Monitoring

The acceptance of non-domestic wastewaters into publicly owned treatment works (POTW) could result in harm or damage to the POTW's treatment system. In response to this threat of damage, Congress established the National Pretreatment Program to provide POTWs with means for protecting themselves from the hazards that are associated with accepting non-domestic wastewater. Portions of the National Pretreatment Program require a POTW to establish discharge limits and a compliance-monitoring program. These two segments of the National Pretreatment Program are important to its overall success.One of the POTW's major tasks in the implementation of the National Pretreatment Program is to develop and employ appropriate discharge limits for its non-domestic users. There are three types of discharge limits that can be used: categorical, prohibited, and local. The determination of these limits may be influenced by the resurgence of water quality approaches to managing water bodies, i.e. the Total Maximum Daily Load (TMDL) program. Implementation of the TMDL program may have a significant effect on the development of local discharge limits. The possible effects of the TMDL program on the determination of discharge limits are explored in this paper.Once the proper discharge limits have been determined, the POTW needs to monitor its permitted non-domestic or industrial users (IUs) to ensure that they remain in compliance with their discharge limits. National Pretreatment Program regulations require a POTW to develop a monitoring program; however, there is little detailed guidance on its development. This paper investigates the development of a compliance-monitoring network utilizing a technique initially proposed for surface water quality management networks. In addition, a supplemental Quality Assurance/Quality Control program is explored to enrich the monitoring procedures of the POTW's Pretreatment Program.