groundwater pollution

pollutant plume

When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated. In Florida, for example, more than 90% of wells have detectible contaminants and thousands have been closed.

filtered water

Groundwater is a bit safer from pollution than surface water from some types of pollution because some pollutants are filtered out by the rock and soil that water travels through as it travels through the ground or once it is in the aquifer. But rock and soil cant get out everything, depending on the type of rock and soil and on the types of pollutants. As it is, about 25% of the usable groundwater and 45% of the municipal groundwater supplies in the United States are polluted.

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how pollutants enter groundwater

Groundwater pollutants are the same as surface water pollutants: municipal, agricultural, and industrial. Ground- water is more susceptible to some sources of pollution. For example, irrigation water infiltrates into the ground, bringing with it the pesticides, fertilizers, and herbicides that were sprayed on the fields. Water that seeps through landfills also carries toxins into the ground. Toxic substances and things like gasoline are kept in underground storage tanks; more than 100,000 of the tanks are currently leaking and many more may develop leaks.

instructional diagrams

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questions

which is a source of surface water pollution?

a) municipal pollutants

b) agricultural pollutants

c) industrial pollutants

-->  d) all of the above

more than 100,000 tanks of toxic substances are currently leaking underground.

-->  a) true

b) false

this much of the municipal groundwater supplies in the united states are polluted.

a) 25%

b) 35%

-->  c) 45%

d) 55%

what is a pollutant plume in an aquifer?

-->  a) contamination that travels from the pollutant source in the direction of flow.

b) contamination that travels through an aquifer at a higher speed than the water flows.

c) water that travels down the flow gradient through a polluted region.

d) none of the above

about 25% of groundwater in the united states is polluted.

-->  a) true

b) false

pollutants in an aquifer may

a) be filtered out by the rock or soil.

b) remain in the aquifer.

c) travel very slowly through the rock.

-->  d) all of the above.

groundwater is often contaminated by

a) irrigation water.

b) underground storage tanks.

c) water seeping through landfills.

-->  d) all of these.

a contaminated well will be located

a) only in areas where there is surface contamination.

b) only in areas that are downstream from an industrial pollutant source.

c) only in farming areas.

-->  d) anywhere.

groundwater that moves through the rock aquifer for years is decontaminated and drinkable.

a) true

-->  b) false

fortunately, toxic chemicals that leak onto the ground remain on the ground and do not get into the groundwater supply.

c) true

d) false

diagram questions

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