National Water Summary: Ground Water Resources, Maryland and the District of Columbia
By Laurence J. McGreevy and Judith C. Wheeler
Excerpt from Introduction
Ground water is an abundant natural resource in Maryland. Although it constitutes only 13 percent of total water used in the State, it is of substantial cultural and economic significance. The area east of Chesapeake Bay is dependent almost entirely on ground water for freshwater supplies. Maryland's aquifers provide water for nearly 1.3 million people (about 30 percent of the State's population) and for industry, irrigation, and other uses. In contrast, the District of Columbia depends mostly on surface-water supplies, although nearly 1 million gallons per day (Mgal/d) of ground water is used for industry. Ground water also is relied on for emergency backup for some hospitals, Government facilities, and embassies. Ground water was very important to the District of Columbia during its early years and was the sole source of water until the city began to use surface water in 1859 (Johnston, 1964, p. 42, 46). Ground-water withdrawals in Maryland and the District of Columbia in 1980 for various uses are given in table 1.
