National Water Summary: Groundwater Resources, Maryland and the District of Columbia
By Laurence J. McGreevy and Judith C. Wheeler
Excerpt from Introduction
Groundwater 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 Groundwater 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 Groundwater is used for industry. Groundwater also is relied on for emergency backup for some hospitals, Government facilities, and embassies. Groundwater 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). Groundwater withdrawals in Maryland and the District of Columbia in 1980 for various uses are given in table 1.