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SUMMARY (Continued) . compact-apportioned waters, depletions could increase to 15 million acre-feet annually. Unless control measures are implemented to prevent the salinity increase, annual salinity concentl'ations at lmpedal Dam are est imated to increase horn the 1983 measured, avel'age level of 710 mg/t to an average of 1,012 mg/L by 2010. W .t:. en Plan Formulation Activities :.:t A planning team consisting of State and Federal Government agency l'epl'esentatives and interested publics was formed in 1981. The team was l'esponsible primarily fol' the genel'ation and review of baseline data in addition to other specific tasks; thus, its recommendations were con- sidered in plan formulation and in selection of the alternative evalua- tions. The public was involved 1n the study primarily through planning team activities. tn addition, five public meetings were conducted which provided an additional opportunity for exchange of ideas and viewpoints on the unit. . Two environmental scoping meetings were held 1n May 1982--one at Glenwood Springs and one at Loma--to identify significant potential environmental impacts which should be analyzed and presented in the en- vironmental impact statement. The main concern expressed at the Glenwood Springs meeting was the absence of an alternative which would provide local benefits. Participants at the Lorna meeting were concerned mainly about potential local impacts from evaporation ponds. In addition to meetings, the Bureau of Reclamation has continued to keep the local public informed through news releases, meeting summaries, newsletters, and informal contacts. Plan Formulation Concepts Evaluating conceptual methods of salinity control was the first step in formulating alternative plans. Collection, desalting, convey- ance, and disposal were identified for control of the saline flows enter- ing the Colorado River from the Glenwood-Dotsero Springs Unit. Collection methods identified included surface collection such as catchments or alluvial wells. Catchments would be made by collecting brine in a perforated pipe which is either buried in a spring or struc- turally covered at the sUl'face. Alluvial wells, which provide more con- trol of collection than catchments, would be drilled at strategic points in the alluvium and the saline water pumped at flow rates which maintain the desired saline/fresh ~ater boundary. . Desalting methods considered were reverse osmosis and electrodial- ysis. Reverse osmosis is a process in which water is forced by hydraulic pressure through a semipermeable membrane. Although the membrane is 5-)