San Antonio's Water Reuse Efforts

In 2002 the San Antonio Water System (SAWS) completed construction of the nation's largest recycled water system. To reduce dependence on the Edwards Aquifer, and in support of State Water Plan objectives for reuse and conservation, it delivers 35,000 acre-feet per year to industrial and commercial customers. Additionally, the system uses the same infrastructure for delivery of water to the San Antonio River and Salado Creek for streamflow augmentation. To create maximum reliability and water supply redundancy, interconnections within the recycled system and between the plants that supply recycled water are planned. Effluents for stream discharges will originate at different facilities and be commingled. However, permitting rules did not contemplate that such a system could exist. The San Antonio Water System is asking the State of Texas and EPA to consider a new permitting paradigm that emphasizes the managing of mass loadings. The ‘integrated municipal permit’ approach support Texas' objective of TMDL watershed management and EPA's new policy of watershed-based NPDES permitting. It will provide operational flexibility and greater environmental protection. Once approved, this centralized permit will set a new standard for wastewater discharge permits. In addition to a discussion of permitting implications, the paper will detail system development and start-up challenges and successes, such as water quality corrective actions and pipeline failures.