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WATER RESOURCES " l(j C'1? N .... Water Quality Salinity 1. Question - What are the impacts on salinity in the Colorado River from the project? Answer - At Imperial Dam, an increase in salinity of 2.8 mg/l from stream depletions, resulting in $644,000 in economic impacts and 1,2 mg/l from salt loading effects, resulting in $276,000 in impacts. The increased salt load effects represent 0.1% of the 1976 modified base salt concentration at Imperial Dam, 2. Question - Will salt-bearing formations underlying the reservoir basins become a salinity problem? Answer - It is predicted that there will be no solution enhancement in the reservoirs from underlying formations, A large number of drill holes and test pits have been completed at both reservoir basins with no evaporites or concentrations of saline minerals found. 3. Question - Is the salt-bearing Lewis Shale a potential salinity problem in the Pot Hook Reservoir basin? Answer - No. Only very limited areas of Lewis Shale outcrop in the reservoir basin. Where the formation was penetrated by test hole drilling, it is dense and impervious, Therefore, no leaching of large salt loads would be expected. 4. Question - Is the Mesaverde Formation a potential salinity problem in Sandstone Reservoir basin? Answer - No. Test hole drilling indicates the Mesaverde Formation relatively impermeable, Also, in the reservoir basin it is covered by colluvial and alluvial deposits that would greatly reduce any salt leaching possibilities, 5. Question Is the Mancos Shale a potential problem? Answer - No. . The two reservoirs, canal systems, and irrigated lands in the project do not come into contact with Mancos 'Shale.