The Yin and Yang of Groundwater

Abstract

As an early-career geologist in the late 1980s, I went into hydrogeology because there were no jobs in oil or mining, which was where I expected to work. But I did find a job as a field geologist working at drilling sites for water supply, geotechnical characterization, and environmental remediation. The first week on the job a mentor lent me a textbook, Groundwater, and a journal, Ground Water. Practically, the first thing I read was the editorial by R. Allan Freeze titled “Groundwater is Probably One Word (Or Maybe Two), More or Less: An Allegory.” I found the one-word two-word debate mildly interesting, but more importantly at the time, I was astounded that such a detail as the proper spelling of “groundwater” had not been fully worked out in the groundwater community by the time I entered the profession. I figured there might be a little room for me to contribute and decided to pursue groundwater as a career. Even by then, I had felt a bit of a Yin-Yang ring to groundwater. I quickly realized a deeper dualism in groundwater, which is that all groundwater problems require knowledge of both hydrology and geology, which are very different disciplines each with their own unique theories and methods of discovering new knowledge, the Yin and Yang of groundwater. The water and rocks through which it flows impart different but complementary forces that interact and form a dynamic system in which the whole, for example, an aquifer, is greater than the sum of the parts. To better understand the water part of groundwater, I went back to school to study hydrology and became a hydrogeologist. I embarked on a lifelong mission to learn everything there is to know about groundwater. That, obviously, was a very naïve mission. The more I learn the less I know. But there is an even deeper duality in groundwater in that it is almost the perfect combination of theory and practice. As Dr. Molz recently noted (vol. 55, no. 1), “In natural subsurface systems … reality lies outside of the computer and cell phone screens, and we have to stay in touch with that reality. Thus, field experience is more vital than ever.” Amen. A computer model cannot solve problems or discover new knowledge without data, and the results of a hydrogeologic field test such as a well test or tracer study cannot be useful without a sound theoretical foundation. The field data must be combined with theory, and vice versa, to gain insight and solve problems. Thus, the study of groundwater requires equal measures of both theoretical knowledge and real-world data. Hydrogeology is at once cerebral and physical, imaginative and practical, and abstract and hands on. To go from field work one day to computer modeling the next can be inspiring and satisfying, which I suspect is a common attraction for most groundwater professionals. It is this combination of right-brain left-brain thinking, I believe, that is the true essence of groundwater—its Yin and Yang. This leads me to the Technology Spotlight column for which I am the Editor. My vision for this column is to capture, highlight, and amplify this theoretical-practical duality in groundwater. To that end, we will continue to publish reviews of new software and hardware technologies. In addition, to give Groundwater readers the direct access to relevant, interesting nonproprietary technical reports, we will now publish Executive Summaries of such reports in the column. This opens the door for “publication” to groundwater consultants and engineers who have completed an interesting and publicly available technical report that contains an important contribution in the field of hydrogeology, but who do not have the time and resources to develop a full blown peer-reviewed case study paper. The executive summary receives editorial review, but not peer review and the underlying report will be made available as online Supporting Information.