Innovative Approaches to Reuse Development for Fast Growing Cities, The Frisco Case Study

With limited financial resources, rapid growth and large irrigation loads, The City of Frisco saw reuse as a perfect opportunity to assist in managing their treated water demands. Although the City currently has a water conservation plan in place, summer irrigation loads continue to place a tremendous amount of stress on the treated water system. Building large transmission lines and storage tanks to meet these summer demands can result in water quality problems during low demand periods.The City of Frisco and Freese and Nichols developed a plan to expand the existing nonpressurized reuse system, with a current demand of 1 MGD, to a system with multiple pressure planes serving a summer water demands in excess of 20 MGD within the next 10 years. The project also assisted the City in defining the roles and responsibilities of each entity in the reuse system.The City of Frisco and Freese and Nichols are in the process of designing improvements to the current reuse pump station and piping modifications at the site of the potable water tank that will be converted to a reuse facility. Capital improvements have been identified to serve demands for the first ten year period, and the study is in the final stages of identifying improvements to serve buildout demands for the reclaimed water system.Coordination of the reuse system involved not only multiple departments in the City but also the wholesale wastewater provider. Other challenges encountered in planning the reuse system include: permitting, regulatory record keeping and reporting requirements, interdepartmental coordination, required effluent quality, irrigation schedule coordination, public education, and evaluating and demonstrating the cost benefits of reclaimed water system development. A majority of the future customers for Frisco's reuse system would require the higher level of effluent quality, “Type I” usage. The effluent quality at the existing wastewater treatment plant did not consistently meet the higher requirements of Type I reuse customers; therefore, alternatives were evaluated to determine the best long term solution for integrating the new Type I customers into the system along with a new source, the new Panther Creek Wastewater Treatment Plant (WWTP).Development of the reuse system for this rapidly growing city afforded multiple opportunities for innovative approaches, such as conversion of underutilized treated water facilities to reuse facilities, installation of reuse lines with new road construction and prioritizing potential customers based on proximity to the reclaimed water source. These approaches led to cost savings to the City by “thinking outside of the box”. Although the reuse system will involve an investment by the City, the reduction in the higher potable summer demands will allow the City to save money by downsizing some of the potable water system infrastructure.The reuse system will be phased in over the next 10 years as new roads are designed and additional treated effluent is available. Potential reuse customers in the lower service area were given higher priorities due to their location to the source and not having to pump the reclaimed water twice.