NAIAD Foresight is an on-site measure-and-simulate system that designs water-treatment processes from the site's own water rather than literature values. The portable unit is deployed at factories, hospitals, municipal water sources, and industrial sites, where actual source water passes through configurable treatment stages. By measuring the influent and water after each stage, it captures observed process response rather than relying only on assumptions. A physics-informed neural network uses these measurements to calibrate treatment equations to the specific water. The calibrated model then evaluates combinations of unit process, operating condition, and capacity to determine which treatment stages are needed, how they should be sized, and how the resulting facility should be operated. These recommendations are delivered as a design report with process flow and supporting data. The first facility designed using NAIAD Foresight has been operating at a public hospital in Korea since May 2026