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CHAPTER [V ALTERNAT[VES . .~ - ..... Collection methods identified included surface collection or catch- ments and alluvial wells. Catchments would be made by collecting hrine in a perforated pipe ....hich is either buried in a spring or structurally covered at the surface. Alluvial wells, which provide more control of collection than catchments, are drilled at strategic points in the aqui- fer or seepage alluvium, the springs are then plugged, and the saline water pumped at flo.... rates ....hich maintain the desired elevation of the saline/fresh ....ater boundary. w ~ Desalting methods considered ....ere reverse os~osis and electrodialy- sis. Reverse osmosis is a process in which water is forced by hydraulic pressure through a semipermeable membrane. The membrane is permeable to water under pressure but rejects salts, This creates desalted water on the 10.... pressure side of the membrane and a concentrated brine on the high pressure side. Electrodialysis also employs membrane~ for desalini- zation. A direct current electrical charge separates the salt ions through a selective membrane ....hich results in a stream of prodtlct water and another stream of saline water. Other desalting methods such as distillation and freezing were found during the initial stages of the study to be comparatively costly. . Conveyance options included open channels and pipelines. Both lined and un linen channels were studied. Several types of pipeline material and locations were considered. Deep well injection and evaporation ponds, the most frequently used disposal methods at inland sites, \.lere considered. Deep well injection requires both small brine volumes and a site with suitable lInderp.;round geologic formations to prevent contamination of ground water, Evapora- tion ponds are technically feasible for areas with high evaporation rates, low land costs, and level terrain. The ponds ....ould have potential use for electric generation, algae growth and harvest, wildlife recrea- tion, and other uses. Diversion of the salt water to another river basin ....as evaluated as a disposal option. Transporting coal In a slurry pipe- line was also investigated as an industrial use for saline \.later, Alternatives Alternative DG Plan Concept and AccnMplishMents . With Alternative DG, saline flnws entering the Colorado Rivl'!t' near Dotsero and ;It Glenwood Springs woulrl be collectl'!d ann piped to evapo- ration ponds which ....ould be constructed north....est of !1ack near the Colorado-Utah State line (see Frontispiece Hap), Surface flows would be collected by intercepting natural saline spring flows before they reached the river, while subsurface flows would be pumped from alluvial collector wells, A total of 70 ponds in 4 sections and at varyln~ elevations \.lould be required to evaporate the collected ....ater. and three pump stations would be required to lift the piped flows to the ponds. An automatic 20