Semiconductor foundries and IDMs (integrated device manufacturers) are heavy users of water. Vast amounts of it are used for a variety of purposes from cleaning the wafer between processes to creating humidity in a clean room.

Re-use and reclamation of water is widely practised due to the high costs of cleaning the ultra pure water. Efficiencies are driven by treating the water just enough for the next process. It is common practice to reuse water in a part of the production process which needs less pure water than the first water use. For example, water that was used for rinsing can subsequently be used for cooling.