Perspective on the Synthesis of Unit Operations and Process (UOP) Concepts with Hydrologic Controls for Rainfall-Runoff

Experience over the last decade has demonstrated that there is a significant gap in knowledge between best management practice design/analysis/monitoring and the fundamental unit operations and processes (UOP) that can demonstrate water treatment viability as a function of the hydrologic, physical and chemical characteristics of rainfall-runoff loadings. Such knowledge is critical to the success of a new generation of control strategies, sustainable urban development and low impact development concepts that will develop in response to enological, environmental and regulatory conditions. This editorial discusses the unique nature of rainfall-runoff loadings, differences between rainfall-runoff and wastewater, monitoring and verification of rainfall-runoff UOPs, and the need for UOP concepts and principles. Since structural UOPs alone are not economically sustainable, source control must be an integral part of rainfall-runoff treatment, control and reuse. It is recommended that a synthesis be developed between UOP principles and hydrologic controls while recognizing the uniqueness of rainfall-runoff control, treatment and reuse.