Over the last several years, El Paso Water Utilities (EPWU) of El Paso, Texas, has explored the feasibility of constructing a desalination water treatment plant. Membrane pilot tests using an existing brackish water well were conducted to obtain important information for feasibility analysis and design of desalination plants. This paper summarizes the basic components of a brackish water resources master plan for El Paso based on the results of feasibility analyses, site selections, blending mechanism evaluations, and analyzing alternatives for reject brine disposal. In order to fully utilize the region's brackish water resources, the following key elements were considered in the master plan: desalination methods; inventory of brackish water sources; blending mechanisms; and, brine disposal techniques. In general, total dissolved solids (TDS) is used as an index for the acceptability of the blended water quality. However, in certain areas, such as the Airport/Montana wellfield, chloride is used as an index for blending design because it is the secondary Maximum Contamination Level (MCL) which most exceeds standards. In this paper, several potential brine disposal methods were evaluated as an essential element of desalination. Reverse Osmosis (RO) treatment is evaluated and recommended for implementation. Results conclude that desalination will provide a supplemental water supply for El Paso, and recommend that a desalination treatment facility be designed and constructed with an implementable, low risk, brine disposal alternative. Includes 11 references, tables.
