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EXFILTRATION IN SEWER SYSTEMS: IS IT A NATIONAL PROBLEM?
Citation:
Field*, R, A Selvakumar*, R. S. Amick, AND E. H. Burgess. EXFILTRATION IN SEWER SYSTEMS: IS IT A NATIONAL PROBLEM? Presented at ASCE World Water & Environmental Resources Congress, Orlando, FL, May 20 - 24, 2001.
Impact/Purpose:
present information
Description:
Many municipalities throughout the US have sewerage systems (separate and combined) that may experience exfiltration of untreated wastewater. This study was conducted to focus on the magnitude of the exfiltration problem from sewer pipes on a national basis. The method for estimating exfiltration amounts utilized groundwater table information to identify areas of the country where the hydraulic gradients of the wastewater are typically positive, i.e., the wastewater flow surface (within pipelines) is above the groundwater table. An examination of groundwater table elevations on a national basis reveals that the contiguous US comprises groundwater regions (established by the US Geological Survey) which are markedly different. Much of the northeastern, southeastern, and midwestern US has relatively high groundwater tables that are higher than the wastewater flow surface, resulting in inflow or infiltration. Conversely, a combination of relatively low groundwater table and shallow sewer creates the potential for widespread exfiltration in communities located in the western US.
