BRINE/CONCENTRATE MANAGEMENT STRATEGIES FOR SOUTHERN CALIFORNIA

The U.S. Bureau of Reclamation (Reclamation) has assisted southern California in the planning and development of water recycling projects since 1991 when the Secretary of the Interior announced the Water Recycling Initiative for southern California. This support has been for both project specific and regional planning activities.In 2000, Reclamation and twelve cost sharing partners began the Southern California Water Recycling Projects Initiative (Initiative), which is a multiyear planning study. This study was established to assist local agencies in their recycled water planning for specific projects as well as addressing regional issues that may influence water recycling in southern California. One of the main objectives of the regional component is to assess and analyze potential future brine/concentrate management issues at a regional level. This issue is of particular concern to agencies in southern California that produce recycled water because of the potential salinity increases in water supplies and increasing discharge regulations.This paper will discuss in detail the analysis, results, and information accumulated to date as part of the Initiative project including examining how to address future brine/concentrate issues such as:How much projected future brine/concentrate flows can be expected in the region?What are the applicable technologies?What are the regulations and other implementation barriers facing the technologies or brine/concentrate management strategies?At a regional level, agencies are growing more aware of the limitations that the production and disposal of brine/concentrate can place on the future of recycled water projects. The Initiative project was developed to assist in assessing and analyzing these issues. As part of the Initiative analysis, projections were made for brine/concentrate flow production, increased salinity in water supplies, limitations to effluent discharges, impacts due to conservation, and changes in regulations. These potential impacts were analyzed to determine the impacts on water recycling and will be used in the next phase of this study to evaluate potential regional solutions to managing brine/concentrate and salinity so that the impacts to recycled water are minimized.One of the major components of the Initiative analysis was an in-depth review of applicable technologies for treating and/or disposing of projected brine/concentrate flows. Disposal options and related technologies evaluated under the Initiative Study were grouped into the following categories:Liquid disposalIncineration disposal optionLandfill disposal optionCrystallizationLiquid concentrating/volume reducingZero Liquid Discharge