U.S. Geological Survey ground-water studies in Pennsylvania

In Pennsylvania, large water demands generally are met from surface-water sources; small water demands generally are met from ground-water sources. Ground-water sources supply 6 percent of the total water used in Pennsylvania. Of the ground water used in 1984,55 percent was for industry, 23 percent for public supply, 15 percent for rural domestic supplies, 5 percent for livestock, and 2 percent for irrigation. Public supplies provide ground water to about 2,180,000 people, and rural self-supplied systems provide ground water to about 3,000,000 people.  The major issues related to ground water in Pennsylvania are: Adequacy of supplies, Contamination by hazardous wastes, and Effects of coal mining, oil and gas production, and agriculture.