TURNER, KENNETH H., Kern Country Water Agency, Bakersfield, CA

ABSTRACT: Hydrogeologic Evaluation of the Kern River Alluvial Fan Area and the Importance of the Degree of Confinement of a Multi-Aquifer System

There has been an extensive hydrogeologic study, over a 6-yr period, to evaluate the potential for large scale recharge and extraction of water within the Kern River alluvial fan sediments over an approximate 24,000-ac area on the Bakersfield arch. A combination of aquifer tests, temporal variability of vertical hydraulic head differences, groundwater flow modeling, historical artesian flow data, seismic reflection data, and geochemistry data suggests that the areal extent of the Corcoran Clay Member of the Tulare Formation was restricted in the proximity of the Bakersfield arch. The Corcoran Clay, part of the more extensive E-clay, has been considered to be a significant aquitard throughout a large portion of the San Joaquin Valley. The apparent lack of the Corcoran Clay or other lat rally continuous clays within the Pleistocene to Holocene sediments to serve as a significant aquitard in the vicinity of the Bakersfield arch is important to the operational decisions of a large-scale recharge and extraction facility in this area. The interpretation of a multi-aquifer system consisting of an unconfined aquifer and semiconfined (leaky) aquifers is critical to water well completion decisions and contaminant transport considerations on and peripheral to the Bakersfield arch.

AAPG Search and Discovery Article #90992©1993 AAPG Pacific Section Meeting, Long Beach, California, May 5-7, 1993.