WSP08407 - Laserfiche WebLink

Home Browse Search

. . . o ~ N en CHAPTER II NEED FOR ACTION Approximately 100 wells were drilled between 1975 and 1978 to gather information about a deep artesian aquifer, shallow aquifers, and poten- tia1 recharge areas. Investigations showed that the deep aquifer had no apparent hydraulic connection with the shallow aquifers, and that seepage from Big Sandy Reservoir waa not a contributor to the saline seep problem. Pumping of selected wells in the shallow aquifer near the Big Sandy River resulted in greatly reduced flows of nearby seeps. Additional investigation was initiated on the Big Sandy River in October 1981. Flow and conductivity measurements were taken at six locations along the river from its confluence with Little Sandy Creek to Casson Bridge. Data collected indicate that most of the salt loading occurs in the Big Bend and Bone Draw areas. Surface and well water quality sampling and water surface elevation measurements are being con- t inued. Additional geochemical methods will be utilized to determine whether the deep aquifer is a contributor to salt loading. The total flow from the observable springs and seeps is estimated at 11 cfs, with an average concentration of about 4,000 mg/L and a corresponding salt loading estimated at 45,000 tons per year. Four readings taken in October and November 1981 showed an increase in Big Sandy River flows of 32 cfs from all sources between the confluence and Gasson Bridge, with an average concentration of about 3,900 mg/L and a corresponding salt load of approximately 123,000 tons per year. The saline flows not entering from observable springs and seeps apparently enter through the river bed in the vicinity of Bone Draw. Conductivity 29