Abstract
The groundwater aquifers beneath the California State University, Sacramento were characterized by evaluating the hydraulic conductivity, transmissivity, and storativity of the aquifers. Multiple methods were used to analyze slug test and pump test data, and boring logs were used to estimate appropriate input parameters. Two distinct aquifers were identified beneath the campus: a shallow unconfined aquifer and a deeper confined aquifer. The shallow unconfined aquifer can be expected to have a range of hydraulic conductivity values between 40 and 90 feet/day. The deeper confined aquifer can be expected to have a range of hydraulic conductivity values between 100 and 200 feet/day, transmissivity values between 1,500 and 4,500 square feet/day, and storativity values between 1.0x10-5 and 1.0x10-4. Evaluation of the lithologies and aquifer characteristics allowed for an assessment of the potential hazards that could affect the aquifer and some general statements regarding the potential risk to the aquifer from hazards can be made. There is significant risk that land use activities have or will impact the underlying shallow unconfined aquifer because the overlying material has high porosity and permeability. Contaminants released at the ground surface have the potential to percolate into the shallow groundwater. The deeper aquifer has less risk of being contaminated from surface releases because a confining layer separates it from the overlying aquifer. However, contaminants could reach the deeper aquifer through preferential flow paths caused by poor drilling and well construction practices or gaps within the confining layer.