Leonard T. Wright
Abstract
The control of wet-weather sanitary sewer overflows is characterized as an engineering design problem. The goal is to control the long-term pollutant discharge to the receiving water while minimizing cost. Available control options include increased treatment rate, storage, and flow reduction by rehabilitating deteriorated collection system components. Discriminant analysis based on a least cost classifier is used to estimate the physical condition of the uninspected portion of the collection system. A bootstrap error estimate is used to aggregate pipe condition results to a sub-basin level. The effect of reduced wet-weather flow on downstream conveyance upgrade costs is characterized as a metamodel. A series of detailed hydraulic analyses provide data points for a simplified function of cost and effectiveness for rehabilitation and conveyance. This function is used to develop a nonlinear program, which is used to find the optimal blend of storage, treatment and upstream flow reduction, while meeting long-term performance constraints. A stochastic integer program for this design problem is developed to include the effect of uncertainty on the optimal solution. A series of trade offs between solution reliability and system cost is presented for a wide range of performance levels.
Ph.D. in Civil Engineering
University of Colorado Boulder
2003
Committee Members
James P.l Heaney
Manuel Laguna
George W. Morgenthaler
Harihar Rajaram
Kenneth Strzepek