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Degree

MS, University of Cincinnati, Engineering and Applied Science: Environmental Engineering, 2012.

Abstract

The effectiveness of controlled partial exfiltration of storm water from sewers is evaluated as an option for managing urban runoff. Steady and unsteady exfiltration from storm sewers is simulated using a modified version of the USEPA Storm Water Management Model (SWMM) program. Exfiltration is represented in SWMM as a distributed sink term in the St. Venant equations for one-dimensional, gradually varied, unsteady flow. The sink term is modeled as an orifice with discharge coefficient dependent on the velocity head in the pipe. The spatial variation of exfiltration rate along the pipe length is also considered in the model. SWMM simulations indicate that exfiltrating sewers can provide significant reductions in the peak flow and runoff volume. Dimensionless charts are developed to offer a quick design aid to determine the expected performance of an exfiltrating sewer under a wide variety of rainfall loadings and soil conditions. A simple step-wise solution is presented to determine the water surface profile in a perforated pipe. This simplified approach facilitates the determination of exfiltration losses from the pipe under steady state conditions. A life-cycle cost analysis reveals there are economic benefits associated with selecting an exfiltrating storm sewer system over a conventional storm drainage system.

Subject Headings

Environmental Engineering

Keywords

Exfiltration; perforated pipe; dimensionless charts; SWMM; storm water management

Committee / Advisors

Steven Buchberger, PhD (Committee Chair)
Jeffrey Yang, PhD (Committee Member)
Dominic Boccelli, PhD (Committee Member)

Pages

94p.

Document number: ucin1342544885
Permalink: http://rave.ohiolink.edu/etdc/view?acc_num=ucin1342544885

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