AWWA JAW69596

Health-based regulations drive up the cost of treatment, but about 50% of system design capacity is for irrigation and toilet flushing for which these regulations are irrelevant. Using reclaimed water to eliminate nonpotable demands reduces plant size, and shifting fire protection to reclaimed water keeps water residence time short in the potable lines to the benefit of water quality. In dual distribution systems, pipe diameters and water residence times are reduced in potable water lines, resulting in less deterioration in water quality. A case study community shows the benefits and costs of integrating fire protection into the nonpotable water lines in a dual system. Although the financial barrier to adoption of a dual distribution system is a challenge, this article provides a template to assess the costs and the benefits that will be useful to many water utilities. Includes 30 references, tables, figures.