Technology + Field Verification = Mega-savings from Reduced Inflow

Following an extensive capacity assessment of their sanitary sewer collection system, San Antonio Water System (SAWS) recognized the potential cost savings to reduce wet weather inflow throughout the system and significantly reduce the need for capital conveyance projects to increase capacity. Flow monitoring data, hydraulic modeling, and manhole frame and cover leakage testing led to an effort to field inspect over 30,000 manholes in the 100-year floodplain and additional low-lying areas. The inspection effort resulted in a manhole rehabilitation program, and SAWS is employing the use of flow monitoring to observe the change in the system response to a wet weather event in a basin where manhole rehabilitation has begun. This manhole rehabilitation, in addition to other wet weather inflow reduction measures, is anticipated to save hundreds of millions of dollars in capital projects that are rendered unnecessary.