environmental water test

land that drains into a river

watershed

results in an increase of water temperature, can cause large fish kills

thermal pollution

law designed to improve water quality

1972 Clean Water Act

leaking gasoline tank 

point-source pollution 

chemical, physical, or biological agents in water that degrade the water quality

water pollution

global uses of fresh water

irrigation

artificial lake created by building a dam 

reservoir 

underground rock formation that holds water

aquifer

area of land through which water percolates and is stored as groundwater, land above aquifer 

recharge zone 

removing salt from salt water to make fresh water

irrigation

water pollution that washes into storm sewers from many places, such as parking lots and lawns

nonpoint-soure pollution

water safe to drink

potable 

a bacterium, virus or parasitic worm that causes disease

pathogens

process by which increasing amounts of toxins are stored in the bodies of organisms as toxins move up the food chain

biomagnification

process by which nutrients increases in a lake, while oxygen levels decrease  

artificial eutrophication 

water that is found in lakes, rivers and streams is called

surface water

the continuous movement of water between Earth and its atmosphere 

water cycle