Environmental key terms 26-50


All the water on or near earth's surface: oceans, lakes, rivers, ice
caps, clouds.

Water Cycle

The continuous movement of water between air, land, and back
again: evaporation, condensation, precipitation


Water found underground in cracks and spaces of the soil, sand and
rocks. 50% of people in US use groundwater for drinking. Comes
from rain, snow, sleet and hail that soaks into the ground.

Surface Water

Freshwater on land, on the surface of earth. Lakes, rivers, wetlands.
Most cities depend on surface water for their water supply (drinking
water, agriculture, fish, power, transportation).


The area of land that drains into the Potomac River is the Potomac
River watershed. Pollution anywhere on that land will flow into the
Potomac River and eventually into the Chesapeake Bay

.River System

Streams and rivers form a web as they meet and divide across the
land, like the roots of a tree feeding into a tree trunk. Goose Creek,
Algonkian Creek, and Catoctin Creek all flow downhill into the
Potomac River, which flows into the Chesapeake Bay, which flows
into the Atlantic Ocean


Rocks, sand and gravel that hold the groundwater. The "water table"
is the top of the aquifer

.Recharge Zone

The area on the earth's surface that feeds water to the aquifer. Any
pollution in the recharge zone will enter the aquifer. Buildings and
parking lots reduce the recharge zone. Aquifers can take tens of
thousands of years to recharge


An artificial lake formed behind a dam. Can be used for drinking
water, flood control, irrigation, recreation, industry, electrical energy

Potable Water

Water that is safe to drink. Most water must be treated before we can
drink it, to remove poisonous elements such as mercury, arsenic and


Organisms in water that cause disease: bacteria, viruses, parasitic worms.
Found in water contaminated by sewage or animal feces.


Process of removing salt from sea water to make fresh water. Some
countries in the Middle East use evaporation for desalination.

Point Source

Water pollution that comes from a single source such as septic tanks,
landfills, leaking underground gas tanks, wastewater treatment plants

Nonpoint Source

Water pollution that comes from many sources that hard to identify. 96% of
polluted bodies of water in the US come from nonpoint sources such as
runoff from lawn chemicals or streets that contain oil, feces, and litter, oil
poured down storm drains, runoff from farms containing fertilizers, oil and
gas leaked from boats.

Nitrogen Cycle

Process by which Nitrogen is cycled between atmosphere, bacteria and
other organisms. 78% of the atmosphere is Nitrogen but it must be changed
by the nitrogen cycle before it can be used.


The cyclic movement of phosphorous in different chemical forms from the
environment to organisms and then back to the environment.

Waste Water

Water that contains waste from homes or industry that flows to a
wastewater treatment plant.

Sewage Sludge

A product of wastewater treatment that must be disposed of. It can be
incinerated and the ash can be buried in a landfill, or it can be used as
fertilizer if is free of toxic chemicals.


A lake can receive too much runoff carrying nutrients in sewage, fertilizers,
and animal waste. Plants and algae grow more than normal, bacteria feed
on decaying organisms, use up all the oxygen, plants and animals die


A pond or lake that is too low in nutrients (sometimes referred to as a dead

Thermal Pollution

When temperature rises to a level that harms organisms. This can occur
when power plants use water in their cooling systems and then discharge
the water. Increasing the temperature only a few degrees can create a
thermal shock and lower oxygen levels.


Accumulation of pollutants in each level of the food chain. Many states limit
the amount of fish that people can eat from certain bodies of water. DDT to
zooplankton to small fish to large fish to bald eagle.


Occurs when runoff from sewage and fertilizer enters a body of water. It
speeds up plant growth in the water due to all the nutrients in the sewage
and fertilizer. As the plants die, the bacteria use up all the oxygen and
organisms like fish and insects suffocate.

Rachel Carson

Biologist who wrote Silent Spring in 1962 and educated the world about
dangerous use of DDT