Ch. 13 & 20

porous, water-saturated layers of sand, gravel, or bedrock that can yield an economically significant amount of water

water that sinks into the soil and is stored in slowly flowing and slowly renewed aquifers

inadequate oxygenation in the water

downward movement of water through soil

process in which various chemicals in upper layers of soil are dissolved and carried to lower layers and to groundwater

water in the form of rain, sleet, hail, and snow that falls from the atmosphere onto land and bodies of water

mechanical sewage treatments in which large solids are filtered out by screens and suspended solids settle out as sludge in a sedimentation tank

the removal of pollution or contaminants from soil, groundwater, sediments, or surface water

artificial lake created when a steam is dammed

second step in most waste treatment systems in which aerobic bacteria decompose as much as 90% of degradable, oxygen-demanding organic wastes in wastewater

precipitation that does not infiltrate the ground or return to the atmosphere by evaporation or transpiration

any water that has been adversely affected in quality

any physical or chemical change in surface or groundwater that can harm living organisms or make water unfit for certain users

upper surface of the zone of saturation in which all available pores in the soil and rock in the earth’s crust are filled with water

land area that delivers water, sediment, and dissolved substances via small streams to a major stream

zone of soil that is not saturated water and lies above the water table

zone where all available pores in soil and rock in the earth’s crust are filled with water

water flowing off the land into bodies of surface water