APES Chapter 15: Freshwater Systems and Resources

aquifers

an underground water resevoir

confined (artesian) aquifer

A water bearing, porous layer of rock, sand, or gravel that is trapped between an upper and lower layer of less permeable substrate, such as clay. Water is under pressure due to the impermeable upper layer to confine it

consumptive use

Use of freshwater in which water is removed from a particular aquifer or surface water body and is not returned to it. Ex. Irrigation for agriculture

dam

structure that alters the flow of a river by storing water in a resevoir

desalination

The removal of salt from seawater

flooding

The spillage of water over a river’s banks due to heavy rain or snowmelt

floodplain

The region of land over which a river has historically wandered and periodically floods

fresh water

Water that is relatively pure, holding very few dissolved salts

groundwater

Water held in aquifers underground

nonconsumptive use

water from a particular aquifer or surface water body either is not removed or is removed only temporarily and then returned. Ex. Use of water to generate electricity in hydroelectric dams

nonpoint source

A diffuse source of pollutants, often consisting of many small sources

point source

A specific spot (such as a factory) where large quantities of air pollutants or water pollutants are discharged

pollution

The release of matter or energy into the environment that causes undesirable impacts on the health and well-being of humans or other organisms

primary treatment

A stage of wastewater treatment in which contaminants are physically removed. Wastewater flows into tanks in which sewage solids, grit, and particular matter settle to the bottom. Greases and oils flow to the surface and can be skimmed off

reservoir

An artificial water body behind a dam that stores water for human use.

secondary treatment

Bacteria is added to digest organic matter; air is added to give the bacteria oxygen

septic systems

Wastewater disposal method common in rural areas, consisting of an underground tank and series of drainpipes.

sinkholes

An area where the ground has given way with little warning as a result of subsidence caused by depletion of water from an aquifer

surface water

Water located atop Earth’s surface

unconfined aquifer

A water-bearing, porous layer of rock, sand, or gravel that lies atop a less permeable substrate. Water is not under pressure because there is no impermeable upper layer to confine it

wastewater

any water used in households, businesses, industries, or public facilities and is drained or flushed down pipes, as well as the polluted runoff from streets and storm drains

water pollution

The act of polluting water, or the condition of being polluted by water pollutants

watershed

The entire area of land from which water drains into a given river

water table

The upper limit of groundwater held in an aquifer

wetlands

an area of land (often low lying) where the soil is covered/saturated/flooded with water for all or most of the year.