Laserfiche WebLink
<br />.. C;' <br />:":.J <br />U <br />C',J <br /> <br />'-- <br /> <br />o <br /> <br />PROPOSED GROUND-WATER FLOW REDUCTION VERIFICATION PROGRAM <br /> <br />A verification program is proposed to demonstrate salinity control by <br />reduci ng ground~water flow. A sl urry trench/wa 11 wou I d be bu i It from <br />bedrock to ground surface and circumscribe a ground-water detention basin. <br />The basin is expected to raise the elevation of tributary inflow to the <br />Wash such that subsurface flows in contact with native salt deposits would <br />be minimal. The effectiveness of the basin would be evidenced by <br />increasing ground-water salinity in the basin, and decreasing surface water <br />salinity and ground-water table elevation downstream of the basin. Two <br />sites are recommended for the verification program: Detention Basin 14 <br />dnd the Vegetation Test Basin. <br /> <br />Detention Basin 14 <br /> <br />slurry trench/wall length <br />depth <br />est. cost <br /> <br />2,100 ft. <br />20 ft. <br />$168,000 <br /> <br />Advantages: <br /> <br />* <br /> <br />Would intercept largest ground-water inflow to the proposed <br />salinity control area. <br /> <br />Would help provide surface monitoring of an otherwise subsurface <br />perennial flow. <br /> <br />* <br /> <br />* <br /> <br />Would not interfere with surface stream channel that conveys <br />sewage treatment plant effluent. <br /> <br />Vegetation Test Basin <br /> <br />slurry trench/wa 11 1 ength <br />depth <br />est. cost <br /> <br />6,900 ft. <br />30 ft. <br />$830,000 <br /> <br />Advantages: <br /> <br />* <br /> <br />Would provide an operating prototype for the complete detention <br />basin system. <br /> <br />Would'demonstrate surface conditions where ground-water salinity <br />approaches saturation. <br /> <br />Would satisfy requirements for a vegetation test site as <br />described in the May 13, 1983 FONSI for the Pittman <br />Verification Program. <br /> <br />* <br /> <br />* <br />