(301d) Inland Brackish Groundwater As a Resource: Federal Research, Issues, and Challenges

In many arid western communities, groundwater resources once regarded as unusable are under consideration for use in meeting future water needs for drinking and industry.  Technology is available to treat any source of water.  Challenges now are to determine the most efficient treatment solution for a particular situation.  The situation includes the aquifer water chemistry, aquifer productivity, concentrate management options and power options.  A sustainable treatment solution should encompass the entire water path from ground to ground for all streams. 

Reclamation’s Brackish Groundwater National Desalination Research Facility is designed to test and evaluate a range of treatment processes and concentrate management solutions.  The facility has four wells with Total Dissolved Solids levels ranging from 550 mg/L to 4200 mg/L.  There are four outside test pads for medium to large pilot studies and six bays inside for test systems treating up to 20 gallons per minute.  The facility has an evaporation pond for concentrate management studies, an agricultural research area and space for wind and solar powered process development. 

Projects tested at the facility so far address many aspects of brackish aquifer utilization.  There are projects testing alternatives for desalination concentrate minimization, new membrane development, pretreatment membrane materials for produced water, a new method of electrodialysis, and a variety of brackish groundwater pretreatment processes, which have a role to play in the brackish water resource cycle for some situation.  There are still gaps in knowledge of the evolution of brackish aquifers as they are withdrawn.  A holistic approach to community water supply development in areas where brackish groundwater is the only or best solution is proposed in this presentation.  The renewal of the water source and end disposition of all outgoing streams must be considered early in the planning process.