Groundwater is an important source of fresh water in Maryland. Out of a total population of about 5.8 million people, approximately 1.9 million rely on groundwater for their drinking water supply (with the remainder supplied by surface water)(Maupin and others, 2014). Groundwater is nearly the sole source of drinking water in Maryland's coastal plain (area east of I-95). Approximately 1.4 million people rely on groundwater in the coastal plain. While groundwater is not used as much as surface water as a water source, some towns and most domestic users in central and western Maryland also rely heavily on groundwater. Aside from being a crucial drinking water source, groundwater is also important for irrigation, commercial and industrial uses, and power plants (thermoelectric).
In 2010, the primary use of groundwater in Maryland was public supply followed by domestic (self-supplied) and irrigation. Industrial, mining, livestock watering, aquaculture, and thermoelectric use (power plants) accounted for relatively smaller withdrawal amounts.
[Data from Maupin, M.A., Kenny, J.F., Hutson, S.S., Lovelace, J.K., Barber, N.L., and Linsey, K.S., 2014, Estimated use of water in the United States in 2010: U.S. Geological Survey Circular 1405, 56 p., Online Report here]