CHARACTERIZATION OF THE SHALLOW SALINE AQUIFER AT NAS LEMOORE IN WESTERN SAN JOAQUIN VALLEY, CALIFORNIA

The physical attributes of the shallow aquifer at NAS Lemoore were characterized in conjunction with a larger study that was conducted to evaluate soil and groundwater conditions. Increasing salinity in the groundwater of the Tulare Lake Basin is a growing threat to long-term sustainability of use for drinking and irrigation. Characterization of this aquifer is an attempt to understand the dynamics and evolution of a small aquifer subject to salinization.

The aquifer lithology was determined with well log data from 23 irrigation wells and 25 newly constructed observation wells. Additionally, core samples obtained during drilling operations to install the observation wells were analyzed for particle size distribution using a Beckman Coulter LS Particle Size Analyzer located at Moss Landing Marine Laboratories. Deeper aquifer structures were researched in the literature.

The texture of the soil samples varied from sand to silty clay, but the majority of the soil samples were loam. Grain size distributions were analyzed with the HYDRUS 1D computer model to determine the hydraulic conductivity of the soil in each sample. Hydraulic conductivities ranged from 10^-3 cm/sec to 10^-5 cm/sec.

Future analysis will include three-dimensional simulations of the aquifer dynamics using Rockware computer software.