Reductionist hydrogeology: ten fundamental principles

Received 18 July 2008 Accepted 21 July 2008 For over three decades, my hydrogeologic career has blended basic science coupled with providing my expertise to private and governmental entities that need to expeditiously answer questions on water supply, wetland, or contaminant problems. In the process, I discovered that much of what I used to teach in my basic hydrogeology courses, including rigorous mathematical and geochemical tools, could not be used by my students once they left ‘the fold’ unless they became professors who also do basic research. This is because consulting hydrogeologists and engineers usually collect only scant or incomplete data to solve problems, compared to what is collected by academics or United States Geological Survey (USGS) scientists. Regulatory protocols, cost, and the inability of nonhydrogeologists to understand what is done constrain the kinds of analyses done in the ‘real world’. By scant and incomplete data, I mean the installation of fewer than a dozen monitoring wells in a football-fieldsize contaminated site, drilling only two or three test holes for a water supply system, and not collecting analytical data on major dissolved solids and oxygen content of sampled waters. As a consequence of data limitations outside of academia and the USGS, I have become increasingly reductionist in my philosophy on how hydrogeology should be both taught and practised (Siegel, 1999, 2006). Although the sophisticated tools available to hydrogeologists often cannot be used properly in practice, the fundamental concepts underlying the science remain valuable in figuring out what one can do with scant data, and how to efficiently collect data that will be most useful. I write this essay to present my ‘top ten’ list of what students and practising hydrogeologists fundamentally need to know to be successful—the ten points I want my students to remember even 10 years after they graduate.