Another critical feature about the operation of RO wastewater plants is the removal of contaminants from the wastewater. The quality of the filtered water is critical for the type of use anticipated. In one regard, industrial reuse of reclaimed wastewater is most restrictive. Treatment plants like those at West Basin can use the reclaimed water for low and high pressure boilers, process water or irrigation. (Abi-Samra 2002) In places like Singapore, the water is primarily used by the semi-conductor industry for wafer fabrication. In all of these applications, the reclaimed water must conform to very strict purity requirements. One example of the water quality requirement for West Basin is given in Table 1.