A Vertically Compartmentalized, Fracture-Zone, Sandstone Aquifer System
Monday, October 2, 2017: 3:55 p.m.
Todd G. Umstot
,
Daniel B. Stephens & Associates, Albuquerque, NM
Chris Wolf
,
Daniel B. Stephens and Associates, Albuquerque, NM
Michael Fort
,
HydroResolutions, Socorro, NM
Randall M. Roberts
,
Principal & Managing Member, HydroResolutions LLC, Carlsbad, NM
John Wilson, Ph.D.
,
Earth & Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM
A south-dipping sandstone formation in the steeply sloping Santa Ynez Mountains near Santa Barbara, California, appears to be divided into vertically-compartmentalized fracture zones. Observations and testing suggest that each subhorizontal fracture zone acts as an aquifer, with limited vertical communication between adjacent aquifers through intact sandstone matrix and the occasional subvertical fracture. Observations include drilling history, well logs, head measurements, and aqueous geochemistry and isotopes, while testing includes geophysical surveys and well tests. Together the multiple fracture zones constitute a vertically-compartmentalized aquifer system supplemented by storage in the matrix and recharged at higher elevations. Normal faulting limits downgradient, southerly flow. The fault barrier, steep slopes, dipping beds, high-elevation recharge, and vertical compartmentalization lead to significant artesian heads in individual aquifers, each of which can be tapped for water supply, apparently without significant interference between aquifers
Todd G. Umstot, Daniel B. Stephens & Associates, Albuquerque, NM
Todd Umstot received his B.S. in Geology and Environmental Science from the University of Massachusetts, Amherst in 1993 and an M.S. in Hydrogeology from the University of Nevada, Reno in 2002. Since 2002, he has worked as a hydrogeologist for Daniel B. Stephens & Associates in Albuquerque, New Mexico. His professional interests include the study of vadose zone processes, groundwater flow, NAPL migration, and the fate and transport of contaminants.
Chris Wolf, Daniel B. Stephens and Associates, Albuquerque, NM
Christopher Wolf, P.G., is a Senior Geochemist at DBS&A with more than 21 years of experience. He holds master's and bachelor's degrees in geochemistry and geology, respectively, from the New Mexico Institute of Mining and Technology, and is licensed as a Professional Geoscientist in Texas.
Michael Fort, HydroResolutions, Socorro, NM
Michael Fort has more than 20 years of experience in field and laboratory testing, data analysis, modeling and instrumentation for the geosciences. He has worked extensively in the area of site characterization and performance assessment of potential nuclear waste repositories in the United States, France, and the United Kingdom performing and interpreting hydraulic tests, doing performance assessment modeling and developing information management systems. Fort is currently a principal of HydroResolutions LLC.
Randall M. Roberts, Principal & Managing Member, HydroResolutions LLC, Carlsbad, NM
Randall Roberts is a principal and managing member of HydroResolutions in Rio Rancho, New Mexico. He has 18 years of experience performing well-test analysis for nuclear-waste repository agencies around the world. Roberts received his B.S. in geology from North Dakota State University in 1986, and his M.S. degree in hydrology from the New Mexico Institute of Mining and Technology in 1990.
John Wilson, Ph.D., Earth & Environmental Science, New Mexico Institute of Mining and Technology, Socorro, NM
John L. Wilson is Professor Emeritus of Hydrology in the Department of Earth and Environmental Science at the New Mexico Institute of Mining and Technology in Socorro, New Mexico. He has a BS from Georgia Institute of Technology, and MS, CE and PhD degrees from the Massachusetts Institute of Technology (MIT).
His experience includes teaching groundwater hydrology at MIT and New Mexico Tech, and consulting on groundwater issues across the nation. His current consulting is mainly as an expert witness on groundwater and related issues in California. Wilson is a current or former member of many professional society, university and government science advisory panels and committees, former President of the Hydrology Section of the American Geophysical Union, and former Chairman of the Consortium of Universities for the Advancement of Hydrologic Science.
