Monitoring of RO Systems for Regulatory Compliance in Advanced Treatment Systems

The purpose of the paper is to discuss water quality monitoring practices that are associated with the operation of RO systems at Advanced Treated (aka Recycled) Water Facilities. Conventional regulatory approaches with regard to the use of surrogate indicators of operational performance (e.g., permeate conductivity, TOC) are affected by variations in water quality and temperature that increase the concentration of constituents due to diffusion. OCWD uses Normalized Percent Removal to monitor systems for operational purposes. The integrity of the system is a separate issue, and OCWD has established a protocol of conductivity profiling to identify individual pressure vessels within the unit that have integrity concerns.