Most drilled wells in valley bottoms are adequate for a domestic supply. Fewer than half of the wells drilled on hillsides are adequate for a domestic supply, except in areas south of Paintsville where about three-quarters of the wells on hillsides are adequate. Some wells on ridges or hilltops are adequate for a domestic water supply. In the southern part of the county in the Van Lear area, drilled wells more than 200 feet deep in valleys yield enough water for small municipal or industrial supplies. Most of the water from drilled wells is moderately to extremely hard and contains noticeable amounts of iron. In the eastern and southeastern half of the county, salty water can be found in bedrock wells less than 100 feet below the level of the principal valley bottoms. A few springs supply sufficient quantities of water for domestic use. Almost all springs yield less than 5 gal/min.