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PUBH 6011 Unit 8 Latest Update Exam | Questions and
Verified Answers | 100% Correct | Grade A +
describe the major features of the clean water act (eg NPDES)
and the safe drinking water act (eg MCL, MCLG) - ANSWER
MCLG- maximum contaminant level goal- level at which there
would be no adverse effect. Does not take into account cost of
technical feasibility.
MCL- maximum contaminant level - can be adverse effects,
takes cost etc into account
NPDES - national pollutant discharge elimination system,
permitting system under CWA for nutrients and other toxins
from point sources
hydrologic cycle - ANSWER The hydrologic cycle begins with the
evaporation of water from the surface of the ocean. As moist air
is lifted, it cools and water vapor condenses to form clouds.
Moisture is transported around the globe until it returns to the
surface as precipitation. Once the water reaches the ground,
one of two processes may occur;
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1) some of the water may evaporate back into the atmosphere
2) the water may penetrate the surface and become
groundwater.
Groundwater either seeps its way to into the oceans, rivers, and
streams, or is released back into the atmosphere through
transpiration.
The balance of water that remains on the earth's surface is
runoff, which empties into lakes, rivers and streams and is
carried back to the oceans, where the cycle begins again.
evaporation transpiration --> condensation -->
precipitation -->
infiltration / collection
what percentage is saltwater covering on earth's surface? -
ANSWER 70%
what percentage is salt water of total water? - ANSWER 96.5
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what is the remaining 2.5% of earths water? - ANSWER fresh
water
what percentage of earth's water is brackish? - ANSWER 1%
What is brackish water? - ANSWER a mixture of salinity
between saltwater and freshwater found in lakes, seas,
estuaries and groundwater
freshwater - ANSWER Does not contain any saltwater and can
be rivers, lakes, streams,ponds, and wetlands
freshwater frozen - ANSWER 2/3 of frozen ice sheets / glaciers
some in groundwater too
freshwater available for human use - ANSWER only 0.3% of total
water on earth is readily accessible for human use
sources of drinking water - ANSWER -groundwater
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-protected runoff water
-surface water
what is groundwater? - ANSWER groundwater fills the spaces
between soil particles and fractured rock underground
Where is the water table located? - ANSWER the surface of the
zone of saturation
is groundwater contaminated? - ANSWER -Usually free of
contamination—bacteria, viruses, suspended solids, chemicals
-Can become contaminated through human activity—source
protection
Is groundwater a renewable resource? - ANSWER -It is
renewable as long as we don't pump it out of the ground too
quickly, then it becomes non-renewable
-Limited in volume—essentially irreplaceable once depleted
what percentage of the population is US groundwater
responsible for? - ANSWER 50%
PUBH 6011 Unit 8 Latest Update Exam | Questions and
Verified Answers | 100% Correct | Grade A +
describe the major features of the clean water act (eg NPDES)
and the safe drinking water act (eg MCL, MCLG) - ANSWER
MCLG- maximum contaminant level goal- level at which there
would be no adverse effect. Does not take into account cost of
technical feasibility.
MCL- maximum contaminant level - can be adverse effects,
takes cost etc into account
NPDES - national pollutant discharge elimination system,
permitting system under CWA for nutrients and other toxins
from point sources
hydrologic cycle - ANSWER The hydrologic cycle begins with the
evaporation of water from the surface of the ocean. As moist air
is lifted, it cools and water vapor condenses to form clouds.
Moisture is transported around the globe until it returns to the
surface as precipitation. Once the water reaches the ground,
one of two processes may occur;
,2|Page
1) some of the water may evaporate back into the atmosphere
2) the water may penetrate the surface and become
groundwater.
Groundwater either seeps its way to into the oceans, rivers, and
streams, or is released back into the atmosphere through
transpiration.
The balance of water that remains on the earth's surface is
runoff, which empties into lakes, rivers and streams and is
carried back to the oceans, where the cycle begins again.
evaporation transpiration --> condensation -->
precipitation -->
infiltration / collection
what percentage is saltwater covering on earth's surface? -
ANSWER 70%
what percentage is salt water of total water? - ANSWER 96.5
,3|Page
what is the remaining 2.5% of earths water? - ANSWER fresh
water
what percentage of earth's water is brackish? - ANSWER 1%
What is brackish water? - ANSWER a mixture of salinity
between saltwater and freshwater found in lakes, seas,
estuaries and groundwater
freshwater - ANSWER Does not contain any saltwater and can
be rivers, lakes, streams,ponds, and wetlands
freshwater frozen - ANSWER 2/3 of frozen ice sheets / glaciers
some in groundwater too
freshwater available for human use - ANSWER only 0.3% of total
water on earth is readily accessible for human use
sources of drinking water - ANSWER -groundwater
, 4|Page
-protected runoff water
-surface water
what is groundwater? - ANSWER groundwater fills the spaces
between soil particles and fractured rock underground
Where is the water table located? - ANSWER the surface of the
zone of saturation
is groundwater contaminated? - ANSWER -Usually free of
contamination—bacteria, viruses, suspended solids, chemicals
-Can become contaminated through human activity—source
protection
Is groundwater a renewable resource? - ANSWER -It is
renewable as long as we don't pump it out of the ground too
quickly, then it becomes non-renewable
-Limited in volume—essentially irreplaceable once depleted
what percentage of the population is US groundwater
responsible for? - ANSWER 50%
