AWWA WQTC71336

For the past ten years, the majority of the City of Santa Monica's water source has been imported water from the Metropolitan Water District of Southern California due to methyl-tert-butyl-ether (MTBE) contamination in its groundwater supplies. However, with the cost of imported water rising and the available supply of imported waters decreasing, the City is implementing a proactive program to develop new sources and restore impaired resources. Restoring the City's impaired groundwater supply would greatly reduce the City's reliance on imported water supplies and have a more sustainable water supply portfolio. This paper provides an overview of the City's multi-barrier treatment approach and describes the challenges and findings from pilot testing that was conducted to optimize iron and manganese removal, establish pretreatment conditions for reverse osmosis (RO) membranes, and assess RO membrane performance in meeting the City's water quality objectives. Includes figures.