AP Environmental Science Chapter 18: Water Pollution


Terms in this set (...)

Clean Water Act of 1972
an act that helped a lot restore ecosystems
water pollution
any change in water quality that affects it or organisms
point sources
pollution sources that discharge it from specific locations, like sewers
nonpoint sources
scattered or diffused, having no specific location where they discharge into a particular body of water
atmospheric deposition
nonpoint pollution of contaminants carried by air currents and precipitated into water
waterborne diseases
typhoid, cholera, bacteria dysentery, polio
coliform bacteria
water control personnel analyze water for the presence of these
-any of the main types that live in the colon or intestines
Major Categories of Water Pollution
infectious agents
organic chemicals
inorganic chemicals
radioactive material
plant nutrients
oxygen-demanding wastes
biochemical oxygen demand (BOD)
a useful test for organic waste in water because waste is high in nutrients that stimulate the growth of bacteria that consume oxygen.
-incubate water sample for test and compare to the control sample
dissolved oxygen content (DOC)
testing to measure DOC can tel pollution levels and the health of an aquatic system
-uses an oxygen electrode directly.
Measured in parts per million
oxygen sag
the oxygen decline downstream because of pollution
levels of oxygen in a stream
clean zone -- decomposition zone // septic zone -- recovery zone -- clean zone
water clarity
this is a good measure of water quality and pollution.
rivers and lakes that have clear water and low biological productivity
waters are rich in organisms and organic materials
an increase in nutrient levels and biological productivity
cultural eutrophication
a human-caused increase in biological productivity that is caused by sewage, fertilizer runoff, and stuff that increases nutrients
red tide
a bloom of deadly aquatic microorganisms
-common where nutrients and wastes have washed down
the most used herbicide in America
total maximum daily loads (TMDLs)
the amount of a particular pollutant that a water body can receive from both point and nonpoint sources
source reduction
the best and cheapest way to reduce pollution
primary treatment
the first step in municipal waste treatment. It physically separates large solids from the waste stream. As sewage enters the plant, it passes through a metal grating and a moving screen, then into tanks
secondary treatment
consists of biological degradation of the dissolved organic compounds
tertiary treatment
removes plant nutrients, from the remains of secondary treatment. Passage through a lagoon or binding chemicals
liquid waste or sewage discharged into a river or a sea
septic tank
a tank, typically underground, in which sewage is collected and allowed to decompose through bacterial activity before draining by means of a leaching field.
effluent sewerage
a hybrid between a traditional septic tank and a full sewer system
constructed wetlands
they can cut secondary treatment costs by 1/3. Effluent can be used on crops
keeping the water in one place
pumping out polluted water and removing contaminants
living organisms can be used effectively
Water Legislation
Federal Water Pollution Control Act
Safe Drinking Water Act
Clean Water Act
Toxic Substances Control Act
Resource Conservation and Recovery Act
best practicable control technology (BPT)
required by the Clean Water Act
best available, economically achievable technology
the Clean Water Act set national goals of BAT for toxic substances and zero discharge for priority pollutants