Tuesday, April 1, 2008 : 1:20 p.m.

Evaluation of the Potential Ground Water Resources of a Confined Aquifer, San Diego County, California

Anthony Lizzi, M.S., PG, CHG1, W. Richard Laton, Ph.D.2 and John H. Foster, Ph.D., PG, CEG2, (1)ENSR-AECOM, (2)California State University Fullerton

The Golem well is tapping a confined aquifer which terminates into metavolcanic bedrock. The well has been flowing under artesian conditions since it was installed in September 1951. The Olivenhain Municipal Water District (OMWD) has expressed an interest in determining whether the well has the potential to produce sufficient water resources to provide irrigation water for secondary use. In order for the artesian well to be of beneficial use to the OMWD, it would require approximately 2,000 acre feet per year (AFY).

The geologic mapping indicates that an interconnected fracture pattern exists in the bedrock. These fractures facilitate the upper mountain front recharge into the deep interconnected fractures of the metavolcanic bedrock deep within the confined aquifer. The video surveillance of the Golem well showed that the fractured bedrock produced water at depth. A geophysical survey of the well was conducted downole and the data indicated that the confined layer above the fracture zone did not consist of clay material but rather an imprevious layer. Aquifer tests show that the transmissivity values (T) ranged from 800 gpd/ft to 24,500 gpd/ft. Hydraulic conductivity (K) values ranged from 3 ft/day to 72 ft/day. Based on the aquifer test data, the sustainable well yield is anticipated to be between 75 to 80 gallons per minute (GPM). A groundwater flow model using WhAEM was developed for the study area to delineate the capture zone for the aquifer system using time-of-travel which indicated that the capture zone trends towards the northeast, in the upgradient direction, and towards the valley’s higher elevations. The data colelcted during this study will demonstrate whether or not the artesian well will produce sufficient quantity of water for irrigation use to meet OMWD needs.

Anthony Lizzi, M.S., PG, CHG, ENSR-AECOM Anthony J. Lizzi is a employed with ENSR-AECOM in Orange, CA as a Senior Program Director. Anthony has over 20 years experience combined in the mining industry, environmental and remediation filed. He possesses a Master Degree in Hydrogeology and is a professional geologist (PG) and a Certified Hydrogeologist (CHG) in California.

John H. Foster, Ph.D., PG, CEG, California State University Fullerton Dr. John Foster:Professor at California State University, Fullerton. Dr. Foster earned his Ph.D. in Geology at the University of California, Riverside in 1980 on dynamics of plate interaction at Cajon Pass, California. He worked for 10 years in the Geotechnical and Environmental Geologic field with companies in Southern California studying and evaluating active faults, landslides, foundation conditions for large developments and public works. In 1989, he joined the faculty of Cal State Fullerton as an Engineering Geologist and taught courses in field geology and engineering geology and has overseen detailed research activities of over 35 senior thesis students.


2008 Ground Water Summit