Most wells drilled in valley bottoms are adequate for a domestic supply. Fewer than half the wells drilled on hillsides are adequate for a domestic supply, and wells on hilltops and ridges yield less water. In the western half of the county, wells penetrating 500 feet or more of sandstone may yield enough water for a small municipal or industrial supply. Water obtained from most wells in this area is soft or moderately hard and contains noticeable amounts of iron. Salty water may be found in wells drilled less than 100 feet below the level of the principal valley bottoms. A few springs supply enough water for domestic use, usually producing less than 5 gallons per minute.