WEF Guide to Managing Peak Wet Weather Flows in Municipal Wastewater Systems – Wet Weather Management Framework

The Water Environment Federation (WEF), under a Water Quality Cooperative Agreement with the U.S. Environmental Protection Agency, is developing a new WEF guidance document focused on effective practices for managing peak wet weather flows at municipal wastewater treatment facilities. This guidance provides protocols that describe successful wet weather management practices and processes; provide methods to characterize performance of the alternative wet weather management scenarios; provide a framework for identifying and assessing site-specific risks in terms of service delivery, public health, environmental, or other factors; and suggest a framework for planning, selecting alternatives, and implementing wet weather management. In order to provide guidance consistent with the Clean Water Act (CWA), there must be a clear understanding of the regulatory framework in which POTWs function, which provides the context for developing practices and processes and determining that these activities will result in compliance with the Clean Water Act requirements. The Wet Weather Management Framework section of the document provides a new language for POTWs to describe compliance based on system failures and deficiencies. The guidance links the use of risk analysis techniques to evaluate system failures and deficiencies, to identify potential system improvements and determine whether they are feasible alternatives that will achieve improvements in system performance. This Management Framework will support assessment and documentation of utility compliance with the CWA technology and water quality requirements.