Taiwan Semiconductor Manufacturing Co. is investing another $100 billion to expand its north Phoenix wafer-fab complex, a project that uses 4.75 million gallons of water per day. The company says its onsite system currently recycles 65% of that intake—about 3.5 million gallons daily—and it aims to lift reuse to 90% or more by 2028. The unrecycled portion has raised questions from residents and water policy experts about long-term supply in a desert region facing Colorado River cuts.