A Watershed in Our Profession

Abstract

As ground water professionals, we have reached a watershed in our profession. Over the past 50 years, ground water hydrology has developed and matured into a quantitative and sophisticated discipline. The scientific maturity of ground water hydrology is such that researchers are now extending old subject boundaries into interdisciplinary areas such as ground water dependent ecosystems, contaminant biogeochemistry, and societal drivers for ground water use. Are we about to see a gradual deemphasis of ground water skills and decreasing interest as new fields rise to prominence? No, on the contrary; I believe we are just embarking on a path that will reinforce and reinvigorate ground water hydrology as a discipline. In fact, it is likely that our discipline will soon be regarded as fundamental to our very survival. Our world is changing. United Nations statistics show that humans are congregating in urban centers at an astonishing rate. In 1950, the percentage of humanity living in urban centers was 29%; now it is 49% and is expected to reach approximately 60% in the next two decades. Over the same period, global population will climb from 2.5 billion to approximately 8.2 billion, and almost 5 billion people will live in urban centers by 2030. Yet the total amount of accessible fresh water on the earth, held in lakes, rivers, and aquifers, is constant. The United Nations estimates that, currently the global population appropriates 54% of the accessible fresh water, and this fraction will exceed 70% by 2025. With almost 70% of this fresh water demand currently expended on agriculture, it is clear that the amount of accessible fresh water available for domestic use is disturbingly close to a limit. If we assume that the projections are correct, then the need for change in the way we regard our water resource is clear—both quantity and quality are paramount. Even developed nations are now experiencing water shortages, and an estimated 6000 people die each day from drinking contaminated water. Urbanization is not a guarantee of population health. The incredible growth of Asian, African, and South American megacities has generated intractable problems of ground water supply, management, and regulation. As one example, the population of Karachi in Pakistan has grown almost fiftyfold to at least 16 million in the past five decades and the water infrastructure is collapsing. Arsenic and fluoride are found in ground water beneath large areas of densely populated Africa, Asia, and elsewhere, threatening the health of hundreds of millions. In some urban locations, there is rapid transmission of effluents to ground water and potential for hazardous chemical species to persist through the water treatment and disposal trains, thereby increasing in concentration in successive passages through the urban water cycle. Of particular concern here are pharmaceuticals and endocrine disruptors, which may affect a range of life forms at trace concentrations. As fresh water in easily accessible surface water systems is exploited, ground water will become the priority drinking water resource for the future. This simple and expedient choice of water resource will have profound impacts on our relation to water. To use water sustainably in our heavily urbanized future, ground water resources must be protected and managed now through every step of the urban water cycle. Failure to do so may render valuable supplies unusable just when we need them the most. The global call for ground water professionals will only increase. Better identification and characterization of ground water assets will become a growth industry as urban centers proliferate across the world. Application of geospatial characterization techniques from other disciplines may boost productivity and reduce costs associated with this major ground water exploration effort. At the same time, ground water professionals will be required to develop new levels of expertise in assessing ground water quality to secure and manage resources of potable drinking water in heavily urbanized areas where sources of contamination are many and varied. The focus of ground water research will shift from exploitation of supply to sustainability and protection of human and environmental health. Communities around the world will demand high-quality scientific and engineering advice as they deal with the demographic and environmental consequences of expanding urbanization in the face of water limitation. Ground water professionals must be ready to embrace the expanding challenges ahead. This represents a great opportunity for our profession, but the global consequences of failure are unthinkable. It is not a time to be disinterested.