Integrated Planning for Dual Distribution Systems

The southwest region of the US is facing problems with limited water resources and population growth. Some water utilities in the region are taking a proactive approach to planning that incorporates acquiring water resources in the future. Reusing treated wastewater effluent (reclaimed water) is one of the most viable solutions to expand water resources under conditions of fresh water scarcity. Reclaimed water can be used primarily to fulfill the outdoor demands such as landscape irrigation and other non-potable water use. The possibility of treating the reclaimed water to the standards of potable water and using the same distribution system to supply the water is generally not considered to be a viable option. However, cities are studying options to provide dual distribution systems, with separate potable water and reclaimed water systems. Traditional water master plans analyze potable water distribution systems, however with the limitations in water resources, new master plans have started to include consideration of reclaimed water infrastructure. This integrated approach to master planning will help utilities to understand the dynamics of their water sources and utilize the resources effectively. Medium-sized utilities such as the City of Surprise in Arizona have taken the initiative to implement such integrated water master planning to evaluate the feasibility of dual distribution systems.