Wet Weather Flow Management: Planning Challenges and Framework

POTWs have long faced challenges in managing wet weather flows. Traditional approach to wastewater planning has focused on steady state operations and dry weather conditions. Compliance expectations during wet weather have been inconsistent and sometimes undefined. Despite EPA's more than 2 decades of discussing wet weather flow management, clear regulations and guidance on the implementation of the Clean Water Act principles remains elusive. Nevertheless, EPA continues to initiate enforcement actions demanding actions to control CSOs, SSOs, internal plant processes and stormwater to drive water quality and public health improvements. POTWs and municipalities are faced with demands to develop multiple projects and programs based on multiple regulations without clear and adequate planning criteria. Therefore, POTWs and municipalities need to be proactive in addressing the regulators' demands, and that requires a strategy for success. A proactive approach in identifying effective practices for wet weather flow management is built on methods to characterize performance of alternative wet weather flow management scenarios; a framework for identifying and assessing site specific risks associated with POTWs performance; a detailed, community driven process for planning, selecting alternatives, and documenting regulatory compliance; a clear description of protocols to select wet weather management practices from universe of traditional and evolving technologies. Finally, the components of the plan must be laid out carefully to emphasize the values, benefits and community support for he selected plan. That is, make it clear to the regulators that saying “no” to the plan is not an option.