Sewer-Sediment Control: Overview of an Environmental Protection Agency Wet-Weather Flow Research Program

This paper presents a historical overview of the sewer sediment control projects conducted by the Wet-Weather Flow Research Program of the United States Environmental Protection Agency. The research presented includes studies of the causes of sewer solids deposition and development/evaluation of control methods that can prevent sewer-sediment accumulation. Discussions focus on the relationship of wastewater characteristics to flow-carrying velocity, abatement of solids deposition and solids resuspension in sewers, and sewerline flushing systems for removal of sewer sediment. Methods for abating sewer sedimentation include steeper sewer slope, pipe bottom shapes that maintain high velocity during low-flow conditions, and periodic sewer flushing. The future research program plan for sewer-sediment control is also presented.