| Serving professionals in engineering, environmental, and groundwater geology since 1957 | |
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October 2023 CHAPTER MEETING ANNOUNCEMENT |
The speaker will be Dr. Barry Hibbs of California State University, Los Angeles. Dr. Hibbs has taught at California State University, Los Angeles since 1998, where he instructs courses in groundwater hydrology, water quality, watershed analysis, field methods in hydrology, and groundwater management. Dr. Hibbs received a B.S. in Geology from Arizona State University, an M.S. in Hydrogeology from the University of Nebraska Lincoln, and a Ph.D. in Hydrogeology from the University of Texas at Austin. He is a Fellow of the Geological Society of America, a recipient of Cal-State LA's Outstanding Professor Award, and a recipient of the National Ground Water Association Keith E. Anderson Award. Dr. Hibbs' research focuses on the hydrogeology of arid basins; stream/aquifer interactions; isotope and trace element
hydrochemistry; and hydrology of urban areas.
DR. Hibbs is a regular presenter to the Chapter and frequently brings several students to the meetings. He is an advocate for our Chapter/Organization. Please come and show your support and appreciation.
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DATE: |
Wednesday, October 11, 2023
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SPEAKER: |
Mr. Barry Hibbs, Ph.D. in Hydrogeology, Fellow of the Geological Society of
America
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TOPIC: |
"IDENTIFYING TERRESTRIAL GROUNDWATER INPUTS TO NEW WETLANDS ON THE SHORES OF THE RETREATING SALTON SEA, CA"
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PLACE: |
Victorio's Ristorante 10901 Victory Blvd North Hollywood, CA 91606 818-762-9000
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DATE/TIME: |
Wednesday, October 11, 2023 5:45pm - Social Hour 6:45pm - Dinner 7:30pm - Program
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COST: |
$45 per person with reservations in advance for AEG members, $50 without reservations (at the door), FREE for students with a valid student ID and current AEG Student membership, the Student Membership is FREE as well, so join and get a free dinner.
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RESERVATIONS: |
Please email Darrin Hasham at: DHASHAM@EARTHSYSTEMS.COM or call (909) 380-3289.
Please make reservations prior to 3 p.m., Tuesday, October 10th.
No meeting in December due to the holidays. |
Abstract |
New wetlands have appeared near the north and west shores of Salton Sea, Bombay Beach area and Niland Area, California. The wetlands have developed atop semi- perching confining units formed from deposits of "Ancient Lake Cahuilla." This lake had various periods of filling over the last 2000 years, and the lake eventually disappeared around year 1580. Several factors are responsible for the retreating shoreline of Salton Sea, including drought, reduction of seepage from irrigation canals due to canal lining, more efficient agriculture, and short term transfers of Colorado River project water to southern California cities. Wetlands are appearing at locations around the retreating Salton Sea where there is a significant source of terrestrial water. On the north shore in the Bombay Beach area, lining of the Coachella Canal in 2006 is responsible for ending a significant input of canal seepage of Colorado River project water. The Coachella Canal was lined a few decades earlier in the Niland area, but extensive agriculture continues to bring imported water to agriculture providing direct project water and drain water to wetland habitat in the Niland area. Other terrestrial water inputs along the north shore are not especially common, except from temporary winter and local monsoonal rains. At Bombay Beach, the perennial source of terrestrial water comes from a thermal artesian aquifer that supplies water to recreational spas and a fish farm via artesian wells. Waste flows from the thermal spas and fish farm provide input to several local channels that
drain into the new wetlands, providing a constant perennial source of water. The artesian wells tapping the thermal aquifer are completed from 110 to 300 m deep, with temperatures reaching 55 to 80 degrees C at the wellheads. The higher temperatures are associated with the deeper wells. Salinity of groundwater issuing from these artesian wells is in the 4100 to
5200 mg/L TDS range, with a consistent sodium-chloride hydrochemical signature. The thermal groundwater is probably at least 10,000 years old, with no tritium detected and carbon-14 near 3.5 PMC. Water isotopes tested in the thermal artesian water is consistent with a slightly cooler period, and a locally derived source (-71 del D and - 8.7 del O18) with no evidence of any imported Colorado River water. The provenance of the thermal, pluvial groundwater is probably to the north of Salton Sea. Fish farm aquaculture is a notable source of nutrients (N and P) in the flows going into the Bombay Beach wetlands, but no other thermal discharge is a notable source of N or P. In the Niland area, stable water isotopes show that almost all of the water flowing into wetlands is imported Colorado River water, brought to the Niland area for irrigation purposes. In a peripheral but interesting part of the study, the source of water issuing from the Moving Mud Spring near Niland (also called the Niland Geyser, or the Moving Mud Spring, Mundo) is evaluated with stable water isotopes.
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