AWWA MTC64526

In 2002, the Modesto Irrigation District set out on a program to expand their existing treatment works. This paper discusses the criteria used to evaluate and select low pressure membranes to expand the Modesto Regional Water Treatment Plant. Reasons why utilities are selecting low pressure membranes are presented, along with a comparison of conventional vs. membrane treatment on various issues including: raw water quality; level of coagulant/polymer required; comparison of log removals; capital costs; use of permitted spaces; and, use of site space or footprint. Arguments against membrane filtration are given along with a cost comparison of conventional vs. membrane treatment. A schematic of the pilot plant is provided. Includes tables, figure.