NEW OPTIMIZATION TOOLS TO EVALUATE COST-EFFECTIVENESS OF I/I REMOVAL

摘要

Collection system utilities are facing increased costs due to population growth, aging infrastructure and new regulations. At the same time, many utilities are facing a decrease in the funding available to meet their changing needs. As a result, utilities are searching for new, more powerful problem-solving approaches to identify the best solution while continuing to provide a low cost, safe, and reliable service to their customers.The application of Genetic Algorithm (GA) optimization is a powerful approach that many water supply utilities are currently embracing. Cities such as Phoenix, Las Vegas and San Diego are using this technology to reduce costs and enhance system operating performance. GA optimization has been successfully applied to water supply system planning, design and operations since 1995. Until recently, the technology had not been successfully adapted for Collection System Utilities to reduce their system improvement costs through GA optimization.GA optimization can now be applied to stormwater, wastewater, and combined collection systems. This application gives utilities a systematic approach to evaluate millions of possible solutions to resolve complex, multi-objective infrastructure problems and identify the most cost-effective capital improvement program (CIP) or operational strategy. Utilities may customize the infrastructure improvement options, cost estimating procedures and variables, and penalties associated with alternatives to address the specific requirements and needs of their system.Building upon the past success of GA optimization for water distribution systems, CH2M HILL and Optimatics developed a similar GA optimization application for collection systems. This application works with the USEPA Stormwater Management Model (SWMM). SWMM has the capability to simulate gravity and pressure sewer systems and is commonly used to analyze sanitary, combined, and separate storm sewer systems.Johnson County, KS is facing many of the same sanitary sewer collection system challenges common to wastewater collection system agencies throughout the United States. These challenges include basement backups; sanitary sewer overflows (SSOs), aging infrastructure with increasing maintenance needs and regulatory compliance challenges. CH2M HILL and Optimatics worked with Johnson County, KS to apply GA optimization and identify cost effective solutions to collection system problems. These solutions offered significant savings over solutions identified through traditional master planning approaches. This paper presents the GA optimization approach and results for Johnson County's Turkey Creek sewershed.