Development of Hydrologic Concepts in the Northeastern United States

Significant contributions to hydrogeology from the Northeastern United States have resulted from studies of natural phenomena, the occurrence of mineral springs, and two man-made events - the drilling in 1824 of the first fresh water well in the U.S., and the building of the Erie Canal. Development of chemical analytical techniques was prompted by interest in the therapeutic benefits of Saratoga and similar mineral springs, which were used as spas and sources of bottled water. The fundamental concept that the chemical character of ground water is controlled by lithology and by source and movement of water evolved from efforts to explain the origin and chemical differences of springs that were believed to have different medicinal benefits. The first drilled well, at the mouth of the Raritan River, led to the study of saltwater encroachment in the United States. The concept that explains the relationship between freshwater head and the position of the saltwater interface was developed to explain the ebbing and flowing of the well. Although the early hydrologic work was undertaken primarily by chemists and engineers, it was largely the challenge of understanding the position and movement of the saltwater interface that required the talents of geologists from whose studies evolved fundamental hydrogeologic concepts. Even now, evaluation of the role of the zone of dispersion in diagenesis, ore deposition, and geomorphic processes is at the forefront of hydrogeologic research. The building of the Erie Canal demonstrated the delicate ecologic balance of water systems and the need to anticipate the impact of man-made structures on this balance. Hydrologic engineering was advanced during its construction owing to the challenge of controlling the volume of water as well as its depth and velocity.