Deck 17: Water Pollution

Question 1

Thermal pollution differs from most chemical pollution in that

A) Despite being called "pollution", it causes no real harm.
B) It is localized in impact and short-lived.
C) It has by now effectively been eliminated as an environmental hazard.
D) All of the choices are correct.

Answer 1

B

Question 2

When human activities alter natural chemical cycles of elements,they most often do so by

A) Increasing the capacity of the system for an element.
B) Decreasing the capacity of the system for an element.
C) Increasing the rate of input of elements into the system.
D) Changing one chemical element into another.

Answer 2

C

Question 3

The dose-response curve for arsenic

A) Shows no benefit to low concentrations and great harm from high concentrations.
B) Shows that arsenic is beneficial to humans when consumed in low quantities, but toxic at high quantities.
C) Was a major factor in setting the new, lower drinking-water standard for dissolved arsenic of 10 ppb in public water supplies.
D) Shows that microorganisms can be very helpful in decontaminating a site with high arsenic levels.

Answer 3

A

Question 4

In water,the organic matter load is explained by the

A) Biological oxygen demand.
B) Biophysical oxygen demand.
C) Biometric oxygen demand.
D) Biochemical oxygen demand.

Question 5

The gases produced as a byproduct of anaerobic decomposition include

A) Hydrogen sulfide and ethane.
B) Hydrogen sulfide and propane.
C) Hydrogen sulfide and butane.
D) Hydrogen sulfide and methane.

Question 6

The toxicity of industrial pollutants may go unrecognized for all of the following reasons except

A) They often cause skin and eye irritation.
B) Their harmful effects may be slow to develop.
C) They may be harmful only in some concentrations or circumstances.
D) They cannot be tested for safety on all organisms.

Question 7

A lake may be described as "dead" when its condition is

A) Eutrophic.
B) Aerobic.
C) Anaerobic.
D) Saline.

Question 8

When the source of pollutant is readily identified by one location then the type of pollution is called

A) Point source.
B) Nonpoint source.
C) Leachate.
D) All the choices are correct.

Question 9

Lead,mercury and plutonium are these that have a tendency to accumulate in organisms.

A) Radioactive metals
B) Precious metals
C) Native metals
D) Heavy metals

Question 10

Point sources of pollution include all of the following except

A) A septic tank leaking sewage.
B) Salt runoff from roads.
C) Wastewater from a factory.
D) Organic matter discharged from a meat-packing plant.

Question 11

Residence time for water in Lake Tahoe,Nevada/California is 600 years which means that

A) A water molecule entering the lake will remain in the lake for 600 years.
B) The total volume of water in Lake Tahoe remains constant for 600 years.
C) The water in Lake Tahoe will sustain aquatic life for 600 years.
D) Outflow from Lake Tahoe occurs once every 600 years.

Question 12

Mercury

A) Is most toxic to humans in the form of methyl mercury.
B) Is bio-concentrated (concentrations increase up the food chain), with the result that large fish like tuna may contain unacceptable levels.
C) May be added to the atmosphere through the burning of coal, incineration of waste, smelting association with ore processing and processing of batteries.
D) Is transferred from the atmosphere into water, where microorganisms transform it to methyl mercury.
E) All of the choices are correct.

Question 13

Improper agricultural techniques increase erosion rates nine times higher than normal resulting in

A) Sediment erosion.
B) Sediment pollution.
C) Sediment aggregation.
D) Sediment increase.

Question 14

Breakdown of organic matter in the absence of oxygen is this type of decay.

A) Aerobic
B) Anaerobic
C) Biochemical
D) Eutrophic

Question 15

Over time,dissolved magnesium concentration in a lake has reached equilibrium.Input is from streams draining into the lake; magnesium is removed by precipitation in lake sediments.If wastewater discharge upstream doubles the rate at which magnesium is delivered to the lake,

A) The BOD of the lake will double.
B) The BOD of the lake will be cut in half.
C) The residence time of magnesium in the lake will double.
D) The residence time of magnesium in the lake will be halved.

Question 16

Volumetrically,the largest non-point source of pollution in the United States is

A) Cropland.
B) Forested land.
C) Mine sites.
D) Urban storm water runoff.

Question 17

Nitrate in groundwater can be increased by infiltration of runoff from all of the following except

A) Manure from cattle feedlots.
B) Fields treated with synthetic fertilizers containing nitrogen.
C) Sewage-treatment waste water.
D) Glacial melt.

Question 18

In an agricultural region,

A) Spring planting and application of fertilizers and herbicides can result in concentration spikes of these chemicals in rivers, due to spring rains.
B) Crops generally use the fertilizer applied to enhance their growth very efficiently.
C) Herbicides and pesticides are retained in the soil and do not present a water-pollution threat.
D) The use of filter strips in riparian zones (areas adjacent to streams) has not been demonstrated to be effective in reducing nutrient loading of streams.

Question 19

A possible consequence of eutrophication is

A) Reduction of nutrient levels in a body of water.
B) Fish kills, because of the lowered dissolved oxygen in the water.
C) An increase in the biodiversity of the body of water.
D) Sequestration of dissolved toxins in lake sediments.

Question 20

Groundwater pollution

A) Comes only from non-point pollution sources, like fertilizer runoff from farmland.
B) Is readily detectable because the presence of pollutants is obvious from the water's taste or smell.
C) Is very difficult to clean up once it has occurred.
D) All of the choices are correct.

Question 21

Because groundwater flow rates are often slow,groundwater pollution may first be detected many years after the occurrence of contamination and in areas distant from the pollution source.

Question 22

Given the quantitative definition of residence time,the effect of increasing the rate of input of a chemical into a natural system at equilibrium would be to increase the chemical's residence time.

Question 23

The escape of nutrients from sediments can be reduced or eliminated by any of the following strategies except

A) Dredging.
B) Aeration.
C) Chemical treatment of the sediment.
D) Emplacement of a plastic or impermeable clay barrier over the bottom sediments.

Question 24

Water containing an abundance of nutrients,which encourages lush growth of such plants as algae is termed

A) Eutrophic.
B) Aerobic.
C) Biochemical.
D) Accumulative.

Question 25

Which of the following statements is not true?

A) Chemical treatment of sediment can be effective in reducing pollution problems, but it must be repeated every few years
B) Fast-flowing streams are generally better aerated than are lakes
C) A body of water is described as "dead" when it contains fatal concentrations of toxic chemicals
D) An oxygen sag curve describes changes in a stream's dissolved oxygen content along its length below an organic-matter source

Question 26

Dumping lawn clippings into a stream will reduce this

A) Flow rate.
B) Dissolved oxygen.
C) Dissolved nitrogen.
D) Biochemical oxygen demand.

Question 27

What develops as a result of migration of the pollutant by groundwater that forms down-gradient with reference to the point source

A) Contaminant dome.
B) Contaminant deposit.
C) Contaminant basin.
D) Contaminant plume.

Question 28

Ground water contaminated with acid rain percolates through a limestone aquifer.With longer residence time in the aquifer system,

A) Dissolved sulfate in the water will increase.
B) Dissolved nitrate in the water will increase.
C) Dissolved bicarbonate in the water will increase.
D) All of the choices are correct.

Question 29

The pump-and-treat method is

A) The surface treatment of polluted groundwater that has been removed from an aquifer.
B) The process by which municipal sewage is treated before discharge into a river.
C) Ineffective in cleansing contaminated water well enough to be used as a drinking water supply.
D) A fast, effective and inexpensive means of treating contaminated groundwater.

Question 30

Pump and treat technique is used for reversing the damage for

A) Streams.
B) Lakes.
C) Groundwater.
D) Estuaries.

Question 31

Use of microorganisms to break down toxic organic compounds in ground water is called

A) Bioremediation.
B) Aerobic decay.
C) Anaerobic decay.
D) Eutrophication.

Question 32

Naturally occurring concentrations of some toxic elements,such as arsenic,may exceed both recommended "safe" levels and wastewater standards for industry.

Question 33

Groundwater pollution in situ is commonly handled by

A) Waiting for the pollutants to disperse or break down.
B) Chemical decontamination to remove the pollutants.
C) Aeration to restore oxygen levels.
D) All of the choices are correct.

Question 34

Nonpoint pollution sources are more diffuse and thus harder to monitor and control than are most point sources.

Question 35

The threat posed by some synthetic chemicals is difficult to assess because of lack of knowledge of their residence times in natural systems.

Question 36

Dredging of a lake bottom

A) May be done to remove toxic pollutants attached to sediment particles.
B) Can cause sediment pollution.
C) May reduce nutrient recycling from sediments.
D) All of the choices are correct.

Question 37

A factory illegally dumps arsenic-rich wastewater into a lake,where the residence time of the arsenic is 10 years.If the dumping stops,after 30 years,the amount of arsenic in the lake will be one-third what it was when the dumping was stopped.

Question 38

Biochemical oxygen demand is the amount of oxygen needed

A) By humans to breathe.
B) By all organisms in a system, both plants and animals.
C) For aerobic breakdown of organic matter in a system.
D) To destroy all chemical pollutants in a system.

Question 39

Eutrophication of water is accelerated by

A) Increased sediment load from erosion.
B) Addition of oxygen.
C) Reduction in phosphate input.
D) Reduction in nitrate input.

Question 40

Concern about environmental pollution is such that comprehensive health hazard information has now been determined for most synthetic drugs and agricultural and industrial chemicals.

Question 41

Groundwater pollution can be reduced by introduction of microorganisms that may break down some of the wastes.

Question 42

An oxygen sag curve describes how oxygen in a body of water is consumed by organisms,such as fish.

Question 43

Mercury is so toxic in all its forms that it is no longer used except as a poison,as in fungicides.

Question 44

If ground water is contaminated with petroleum products,pumping from a level close to the water table may selectively extract much of the pollution.

Question 45

Chemical decontamination is principally used for small toxic-waste spills in surface waters.

Question 46

Groundwater pollution is most often and most effectively treated in situ,which minimizes the risk of spreading the pollution.

Question 47

After the dangers of DDT were recognized,use of toxic organic chemicals in agriculture was virtually eliminated in the United States.

Question 48

Pollution of surface water has nothing to do with pollution of groundwater.

Question 49

Eutrophication caused by excess runoff of nitrate and phosphate fertilizer from farmland could be avoided by substitution of natural,organic fertilizers,like manures,for synthetic fertilizers.

Question 50

Heavy metals accumulate in organisms,increasing in their amount up a food chain because they are concentrated in larger and larger organisms.

Question 51

Use of settling ponds below farm fields reduces sediment pollution of surface runoff water.

Question 52

Eutrophication does not occur naturally; it is the result of human activities altering the nutrient balance in water.

Question 53

Discharge of effluent from a water treatment plant into a stream increases the BOD of the water.

Question 54

Chemical surveys by aircraft can help identify sites of particularly high probability of toxic-element contamination,such as areas affected by acid mine drainage.