AWWA ACE59911

The use of microfiltration (MF) and ultrafiltration (UF) low-pressure membrane processes for surface water treatment has caught the attention of water plant developers and engineers. Since that time, MF and UF have economically penetrated the water treatment market during the 1990s. One of the current practical operation issues that impacts permitting of MF and UF processes involves the monitoring of the integrity and treatment efficacy of the process to assure regulated public health goals. While challenge testing can demonstrate the ability of an integral membrane process to remove contaminants such as Cryptosporidium and Giardia, integrity breaches can develop in the membrane during normal operation that could allow the passage of such microorganisms. In order to verify the removal efficiency of membrane filtration processes during operation, direct integrity testing is required per the LT2ESWTR (40 CFR 141.728). The final LT2ESWTR are expected at least 18 months after the close of the public comment period, in mid-2005. It is anticipated that the LT2SWTR will alleviate the current inconsistencies among states relative to log removal or disinfection credit applied to the membrane filtration process. This document briefly provides an overview of membrane processes, their application and methods used to verify the integrity of membranes for use in water treatment. Includes 6 references, tables.