San Pasqual Temporary Brackish Desalination Demonstration Facility

The city of San Diego is investigating brackish water desalination for groundwater sources in the San Pasqual Valley. A three stage NF-RO-RO high pressure membrane system was designed to treat the groundwater. Iron and manganese concentrations in the source water were higher than expected and led to fouling of the membranes. A slow sand filter was installed prior to the bag filters to oxidize iron and manganese before the membranes. This was an effective method of treating the groundwater.