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O p t i m i z e d D e c i s i o n S u p p o r t F o r W a t e r , Optimized Decision Support For Water, W a s t e w a t e r , A n d S t o r m w a t e r S y s t e m s Wastewater, And Stormwater Systems Innovation is paying dividends for the growing list of municipalities that leverage the latest technology to optimize planning and operations decision making. By Jeffery Frey R eal innovation in the water industry is a goal shared by all stakeholders — municipal and private utilities and their customers; federal and state regulatory agencies, industry organizations, and watchdog groups; equipment manufac- turers and software vendors; and consulting engineers. Nancy Stoner, the U.S. EPA's acting assistant administrator for water, has stated that "technology innovation can accelerate progress toward our goals of clean and safe water. EPA and many stakeholders will strive to support tech- nology innovation to solve water resource problems … cheaper, faster, and using less energy." An example of true technological innovation is the development of formal optimization techniques for the planning and operation of water systems based on hydraulic simulation models. Water systems include water distribution, wastewater collection, stormwater, reclaimed water, irrigation, and even water supply and river basin systems. The simula- tion models include water distribution models, such as EPANET, col- lection system models, such as EPA SWMM, or water resources/supply models, such as REALM. This article provides an overview of this excit- ing technological innovation and its benefits, supported by a number of recent case studies highlighting organizations that achieved substantial results using optimized decision support (ODS) software. Optimization And Optimized Decision Support Everyone likes to believe they "optimize" their project-planning and system operations. Typically, their process is to identify and evaluate a number of options and then select what appears to be the best capital improvement or operating plan that theoretically meets the design and performance criteria. This is accomplished with an up-to-date hydraulic simulation model using trial-and-error and engineering judgment. This approach, however, is not the type of optimization that qualifies as technological innovation. True technological innovation requires the use of a powerful, computationally intelligent optimization tool capable of solving both broad questions and the intricacies of complex problems. Water system problems are often highly complex with a seemingly limitless number of options to consider. These problems challenge even the smartest engineers with decades of experience using detailed simulation models. Experience and engineering judgment are invaluable in the search for the best solutions, but far better and faster results can be achieved if an engineer applies the proper optimization tool. Software can support ODS by enabling engineers and managers to evaluate the full range of alternatives in developing cost-effective, near-optimal solutions for capital planning, operations, and long-term control plans. Software-supported ODS represents a significant advance beyond current practice by helping modelers interact far more intel- ligently with their simulation models as they vet numerous promising solutions for consideration by utility decision makers. Benefits Of ODS Approach Today, the ODS approach is becoming a recognized best practice in the water industry, with utility and consultant managers and modelers study- ing the appoach and being trained to utilize the software tools. The ben- efits and value in moving from a simulation-only approach to an ODS approach are impressive. This is evidenced by the level of cost-avoidance achieved on several projects that utilized an ODS approach (see Table 1). Table 1. Comparison of original simulation solution vs. ODS solution Water/Wastewater Utility Cost Using Traditional Planning ($M) Cost Using ODS Software ($M) Investment Avoided ($M) % Reduction Fort Collins-Loveland Water, CO (System-wide plan) $5.9 $3.0 $2.9 49% Las Vegas Valley Water, NV (Pressure zone plan) $9.1 $7.4 $1.7 19% San Diego Water, Alvarado, CA (Main replacement) $55.0 $35.3 $19.7 36% Fort Worth Water Dept, TX (Pipes-only analysis) $260.0 $187.0 $73.0 28% SA Water, Australia (Desalination plant integration) $1,100.0 $403.0 $697.0 63% Bend, OR (Summer operations for energy) $1,895/day $1,460/day $435/day 23% South Bend, IN CSO LTCP Optimization $412.0 $299.6 $112.4 27% Bend, OR Sewer Master Plan Optimization $130.0 $80.0 $50.0 38% Texas City SSO Optimization Pilot $103.2 $82.2 $21.0 20% Capital improvement and lifetime O&M; (operations & mainte- nance) cost savings are drivers for adoption of the ODS approach, par- ticularly due to limited budgets and tighter regulations. Being able to stretch utility dollars to cover more needs and minimize rate increases can help utility managers become more efficient and effective. Besides reductions in cost, the ODS approach offers other benefits: • Protecting public health through the reduction of combined sewer overflows (CSOs) and sanitary sewer overflows (SSOs) • Improving system reliability and sustainability by optimizing for specific emergency scenarios • Improving hydraulic performance in terms of meeting design criteria • Gaining confidence in plans developed using a comprehensive, unbiased, defensible approach • Enabling planners to identify the critical decision choices through more powerful modeling 28 wateronline.com ■ Water Innovations