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SDAG Monthly Meeting
Wednesday, July 16, 2014

Location: Casa Machado
3750 John J Montgomery Dr.
San Diego, 92123

Directions: South side of Montgomery Field (Airport).
happy hour
5:30pm -
Social hour  
Cash Bar.
6:30pm -

Menu: Deluxe Mexican Buffet. Shrimp, Chicken and Beef Fajitas, Cheese Enchiladas.

Cost: $30.00 for non-members, $25.00 for members, $15.00 for students and professors if pre-registered by the deadline, $5 extra if you did not make a reservation. Click the SDAG member checkbox on the reservation form if you are a member.

Reservations: Make your reservation online by clicking the button below no later than NOON, Monday, July 14th. RESERVATIONS CANNOT BE ACCEPTED AFTER Monday at noon. Late reservations/cancellations are preferred over walk-ins or no-shows. Fees payable at the meeting or pre-pay with PayPal.
As a new payment option, there will be a phone credit card reader at the meeting.

If you are a current SDAG member and are not getting e-mail announcements,
make sure the SDAG secretary has your correct e-mail address.

7:30pm -

Speaker: Dr. Robert Anders, USGS, CA Water Science Center

"A Geochemical Approach to Determine Sources and Movement of Saline Groundwater in a Coastal Aquifer"

Abstract: For many population centers in coastal areas, future development of the local groundwater resources is limited by the presence of saline groundwater in some parts of the coastal aquifer system. For a study in the coastal San Diego area of southern California, an isotopic approach was used to investigate the sources and movement of saline groundwater. Chemical and isotopic data were collected from multiple-depth monitoring-well sites near the San Diego coastline at discrete intervals to depths of more than 650 meters. The groundwater samples were analyzed for major and minor ions, the stable isotopes of hydrogen, oxygen, and strontium, and radioactive isotopes of tritium and carbon-14. Each chemical and isotopic tracer preserves some aspect of the hydrologic history of the groundwater ranging from the chemical characteristics (major and minor ions), to the source of water (stable isotopes of oxygen and hydrogen), to the types of rock encountered in the groundwater flow system (strontium isotopes), to time-since-recharge (tritium and carbon-14). By using sodium-to-calcium mass ratios, in combination with the isotopic data, the occurrence of saline groundwater as a result of seawater intrusion was distinguishable from groundwater in a previously-saline aquifer that has been “flushed” by fresher continental recharge. The systematic analysis of these tracers indicate that the sources and movement of saline groundwater are dominated by: 1) regional flow of higher-elevation precipitation that recharged many thousands of years ago along deep flowpaths; 2) recharge of local precipitation in relatively shallower portions of the flow system; and 3) intrusion of seawater that primarily entered the aquifer system during pre-modern times. Use of multiple chemical and isotopic tracers provides unique insight regarding the processes affecting groundwater quality, enabling local water agencies to assess the groundwater resources in the coastal aquifer system and begin to reduce the area's reliance on imported water.

Robert Anders is a Research Hydrologist with the U.S. Geological Survey. During his career with the USGS, Robert has focused his research on the application of water-quality and environmental tracers to develop a more comprehensive understanding of the fate and transport of anthropogenic contamination associated with regional ground-water systems. Studies commonly involve analysis of chemical, microbiological, and isotopic data collected from surface- and ground-water samples, completion of field-scale infiltration experiments using wastewater tracers and surrogates for enteric pathogens, and development of geochemical and mathematical models. Robert’s educational background includes receiving a BS and MS in Geological Sciences from San Diego State University and a PhD in Civil Engineering from the University of California in Irvine.

San Diego Hydrogeology Project

Upcoming SDAG meetings - 2014

August 20: Monte Marshall - A Tale of Two Schields, The Canadian and Baltic

September 17: Jill Krezoski - The Mineralogy of Mars

October: Field trip!

Meetings are usually scheduled for the 3rd Wednesday evening of the month. Meeting information on this website is normally updated the second week of the month.

If you have any information, announcements, ads or suggestions for an upcoming newsletter, please submit it to Randy Wagner (2014 SDAG Secretary). Any news regarding upcoming events that may be of interest to the Association or news of your business can be submitted. The submittal deadline for the next SDAG newsletter is the last Friday of the month.
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