A large petrochemical plant (confidential) located in a water-limited area is a major water user. The plant is facing a critical water problem because of several factors: (1) the raw water total dissolved solids (TDS) content has been increasing, (2) water rationing, which limits plant production, occurs during drought periods, (3) the plant is planning for a major expansion that requires major additional water supply; and (4) there is persistent community pressure for wastewater discharge reduction. A water resource management and planning study was conducted for this plant to resolve the water problem. This chapter describes the results of the study and the design of a pilot plant program for the testing of a wastewater treatment and recycling system.