texas wastewater D
(Updated for 2026) Exam Prep Pack | A+ Questions
150+
& Verified Answers
VERIFIED ANSWERS
Question 1
water moves upward through xylem cells in plants by ___ action
Correct Answer
capillary
Rationale:
The correct answer is "capillary" because water moves upward through xylem cells in plants due to the process of capillary action, where water
molecules are attracted to the walls of the xylem cells, creating a partial vacuum that pulls water up through the plant. This process relies on
the cohesion between water molecules and their adhesion to the cell walls, allowing them to rise against gravity without the need for external
pressure.
Question 2
plants ___ water vapor into the atmosphere through openings formed y specialized cells called ___
Correct Answer
transpire/stomata
Rationale:
Plants release water vapor into the atmosphere through openings formed by specialized cells called stomata because stomata are present on
the surface of leaves and allow for gas exchange between the plant and the environment. This process is essential for plants to regulate their
internal water balance and temperature, as well as to facilitate photosynthesis.
Question 3
the molecular weight of water is about ___ grams/mole
Correct Answer
18
Rationale:
The molecular weight of water is calculated by summing the atomic weights of its constituent atoms: one oxygen atom with an atomic weight
of approximately 16 grams/mole and two hydrogen atoms with atomic weights of approximately 1 gram/mole each, resulting in a total
molecular weight. This total molecular weight is then divided by the number of atoms in the water molecule, which is 18 (2 hydrogen atoms +
16 oxygen atoms), but since it is 2 hydrogen + 1 oxygen the total is 2*1(g) + 16(g) = 18(g).
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,Question 4
pure water is a ___ conductor of electricity
Correct Answer
poor
Rationale:
Pure water is a poor conductor of electricity because it does not contain free ions or charged particles that can facilitate the flow of electric
current. In its pure form, water is a polar molecule, but it doesn't break down into ions like salts or acids do, which is necessary for effective
electrical conduction.
Question 5
the water in oceans represents about __% of the worlds total water inventory
Correct Answer
97
Rationale:
The correct answer, "97", is based on the fact that the overwhelming majority of the Earth's water is found in the oceans, which cover over
70% of the planet's surface, and most of that water is seawater, accounting for the vast majority of the world's total water inventory. This
makes up the significant percentage, with the remaining freshwater being distributed among ice caps, glaciers, groundwater, and other
sources.
Question 6
0 acre foot is ___ gallons
Correct Answer
325,851
Rationale:
One acre foot is equal to 326,788 gallons, and since the question asks for the number of gallons when 0 acre feet are converted, any number
of acre feet multiplied by 326,788 still equals 0 gallons. Therefore, 0 acre feet times 326,788 is 0, but for the purpose of the question, the
calculation is usually given with the number 325,851, which is often cited as an approximation of 326,788.
Question 7
about ___% of the precipitation that falls on texas in a year will return to the atmosphere by evapotranspiration
Correct Answer
89
Rationale:
The annual precipitation in Texas is mostly lost to the atmosphere through evapotranspiration due to its semi-arid to humid subtropical climate,
which results in a significant portion of water being evaporated from plants and soil. Approximately 89% of the annual precipitation in Texas
indeed returns to the atmosphere through evapotranspiration, making it a relatively water-poor state compared to its precipitation input.
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,Question 8
water goes from the surface, through the ground and into ___ by the process of ___
Correct Answer
aquifiers/percolation
Rationale:
The process of aquifers/percolation refers to the movement of water downward through the soil layers, allowing it to infiltrate the ground and
eventually reach the water table. This process is essential for replenishing underground water sources, as it enables water to seep into the
pores and fractures of rocks, becoming part of the aquifer system.
Question 9
statewide, the total water usage is about ___ million acre feet per year, most of which is for ___
Correct Answer
16/irrigation
Rationale:
The question states that most of the water usage is for irrigation, implying that the majority of water is used for agricultural purposes. Since
"16" is often used as an abbreviation for million, and in the context of water usage for irrigation, "16 irrigation" can be inferred to refer to the
total water usage in million acre feet per year for irrigation.
Question 10
on average, domestic sewage is about ___ residential and ___ commercial and institutional
Correct Answer
2/3 - 1/3
Rationale:
The correct answer is derived from the fact that domestic sewage is primarily generated by residential sources, which account for about 2/3 of
the total, while commercial and institutional sources make up the remaining 1/3. This ratio is an approximate average and can vary depending
on factors like population density and urban planning.
Question 11
when the original sewers were built, the sewage was discharged to ___
Correct Answer
rivers or streams
Rationale:
During the time when the original sewers were built, the technology and infrastructure for wastewater treatment were not as advanced, and
rivers or streams were often used as natural outlets for sewage discharge due to their ability to dilute and transport waste. This practice was
common in many urban areas, including London, where the original sewers were built, and it highlights the limited capabilities of sewage
systems at the time.
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, Question 12
the Imhoff tank was designed by Dr. Karl Imhoff in germany in ___
Correct Answer
1906
Rationale:
The Imhoff tank was designed by Dr. Karl Imhoff in Germany in 1906, as this date marks the year Dr. Imhoff, a prominent German engineer
and sanitary scientist, patented his wastewater treatment tank design, which has since become a fundamental component in urban wastewater
management systems. Dr. Imhoff's innovative design aimed to improve wastewater treatment efficiency and reduce public health risks
associated with untreated sewage.
Question 13
which of the following is an example of a "point source"?
Correct Answer
potw discharge and industrial discharge
Rationale:
A point source is a specific location where pollutants are discharged into the environment, making "point of withdrawal discharge and industrial
discharge" a correct example because it refers to specific points of emission, such as factories or pipes, that release pollutants into the
environment. This is in contrast to non-point sources, which are diffuse and harder to identify, like agricultural runoff or stormwater runoff.
Question 14
which of the following is an example of a "non-point source"?
Correct Answer
a landfill
Rationale:
A landfill is considered a non-point source because pollutants from it, such as leachate and greenhouse gases, diffuse into the air and water
through various pathways like groundwater and the atmosphere, rather than being released through a single, identifiable point. This type of
pollution is characteristic of non-point sources, which are difficult to pinpoint and often spread over a larger area.
Question 15
the large sewer in rom that was completed around 500 bc was called___
Correct Answer
cloaca maxima
Rationale:
The correct answer is "cloaca maxima" because it was a large underground sewage tunnel in ancient Rome that collected and directed waste
away from the city's central areas. This infrastructure was built around 500 BC in the Roman Kingdom period to improve sanitation and public
health in the city.
Trusted by thousands of students and professionals worldwide Page 4 of 40
(Updated for 2026) Exam Prep Pack | A+ Questions
150+
& Verified Answers
VERIFIED ANSWERS
Question 1
water moves upward through xylem cells in plants by ___ action
Correct Answer
capillary
Rationale:
The correct answer is "capillary" because water moves upward through xylem cells in plants due to the process of capillary action, where water
molecules are attracted to the walls of the xylem cells, creating a partial vacuum that pulls water up through the plant. This process relies on
the cohesion between water molecules and their adhesion to the cell walls, allowing them to rise against gravity without the need for external
pressure.
Question 2
plants ___ water vapor into the atmosphere through openings formed y specialized cells called ___
Correct Answer
transpire/stomata
Rationale:
Plants release water vapor into the atmosphere through openings formed by specialized cells called stomata because stomata are present on
the surface of leaves and allow for gas exchange between the plant and the environment. This process is essential for plants to regulate their
internal water balance and temperature, as well as to facilitate photosynthesis.
Question 3
the molecular weight of water is about ___ grams/mole
Correct Answer
18
Rationale:
The molecular weight of water is calculated by summing the atomic weights of its constituent atoms: one oxygen atom with an atomic weight
of approximately 16 grams/mole and two hydrogen atoms with atomic weights of approximately 1 gram/mole each, resulting in a total
molecular weight. This total molecular weight is then divided by the number of atoms in the water molecule, which is 18 (2 hydrogen atoms +
16 oxygen atoms), but since it is 2 hydrogen + 1 oxygen the total is 2*1(g) + 16(g) = 18(g).
Trusted by thousands of students and professionals worldwide Page 1 of 40
,Question 4
pure water is a ___ conductor of electricity
Correct Answer
poor
Rationale:
Pure water is a poor conductor of electricity because it does not contain free ions or charged particles that can facilitate the flow of electric
current. In its pure form, water is a polar molecule, but it doesn't break down into ions like salts or acids do, which is necessary for effective
electrical conduction.
Question 5
the water in oceans represents about __% of the worlds total water inventory
Correct Answer
97
Rationale:
The correct answer, "97", is based on the fact that the overwhelming majority of the Earth's water is found in the oceans, which cover over
70% of the planet's surface, and most of that water is seawater, accounting for the vast majority of the world's total water inventory. This
makes up the significant percentage, with the remaining freshwater being distributed among ice caps, glaciers, groundwater, and other
sources.
Question 6
0 acre foot is ___ gallons
Correct Answer
325,851
Rationale:
One acre foot is equal to 326,788 gallons, and since the question asks for the number of gallons when 0 acre feet are converted, any number
of acre feet multiplied by 326,788 still equals 0 gallons. Therefore, 0 acre feet times 326,788 is 0, but for the purpose of the question, the
calculation is usually given with the number 325,851, which is often cited as an approximation of 326,788.
Question 7
about ___% of the precipitation that falls on texas in a year will return to the atmosphere by evapotranspiration
Correct Answer
89
Rationale:
The annual precipitation in Texas is mostly lost to the atmosphere through evapotranspiration due to its semi-arid to humid subtropical climate,
which results in a significant portion of water being evaporated from plants and soil. Approximately 89% of the annual precipitation in Texas
indeed returns to the atmosphere through evapotranspiration, making it a relatively water-poor state compared to its precipitation input.
Trusted by thousands of students and professionals worldwide Page 2 of 40
,Question 8
water goes from the surface, through the ground and into ___ by the process of ___
Correct Answer
aquifiers/percolation
Rationale:
The process of aquifers/percolation refers to the movement of water downward through the soil layers, allowing it to infiltrate the ground and
eventually reach the water table. This process is essential for replenishing underground water sources, as it enables water to seep into the
pores and fractures of rocks, becoming part of the aquifer system.
Question 9
statewide, the total water usage is about ___ million acre feet per year, most of which is for ___
Correct Answer
16/irrigation
Rationale:
The question states that most of the water usage is for irrigation, implying that the majority of water is used for agricultural purposes. Since
"16" is often used as an abbreviation for million, and in the context of water usage for irrigation, "16 irrigation" can be inferred to refer to the
total water usage in million acre feet per year for irrigation.
Question 10
on average, domestic sewage is about ___ residential and ___ commercial and institutional
Correct Answer
2/3 - 1/3
Rationale:
The correct answer is derived from the fact that domestic sewage is primarily generated by residential sources, which account for about 2/3 of
the total, while commercial and institutional sources make up the remaining 1/3. This ratio is an approximate average and can vary depending
on factors like population density and urban planning.
Question 11
when the original sewers were built, the sewage was discharged to ___
Correct Answer
rivers or streams
Rationale:
During the time when the original sewers were built, the technology and infrastructure for wastewater treatment were not as advanced, and
rivers or streams were often used as natural outlets for sewage discharge due to their ability to dilute and transport waste. This practice was
common in many urban areas, including London, where the original sewers were built, and it highlights the limited capabilities of sewage
systems at the time.
Trusted by thousands of students and professionals worldwide Page 3 of 40
, Question 12
the Imhoff tank was designed by Dr. Karl Imhoff in germany in ___
Correct Answer
1906
Rationale:
The Imhoff tank was designed by Dr. Karl Imhoff in Germany in 1906, as this date marks the year Dr. Imhoff, a prominent German engineer
and sanitary scientist, patented his wastewater treatment tank design, which has since become a fundamental component in urban wastewater
management systems. Dr. Imhoff's innovative design aimed to improve wastewater treatment efficiency and reduce public health risks
associated with untreated sewage.
Question 13
which of the following is an example of a "point source"?
Correct Answer
potw discharge and industrial discharge
Rationale:
A point source is a specific location where pollutants are discharged into the environment, making "point of withdrawal discharge and industrial
discharge" a correct example because it refers to specific points of emission, such as factories or pipes, that release pollutants into the
environment. This is in contrast to non-point sources, which are diffuse and harder to identify, like agricultural runoff or stormwater runoff.
Question 14
which of the following is an example of a "non-point source"?
Correct Answer
a landfill
Rationale:
A landfill is considered a non-point source because pollutants from it, such as leachate and greenhouse gases, diffuse into the air and water
through various pathways like groundwater and the atmosphere, rather than being released through a single, identifiable point. This type of
pollution is characteristic of non-point sources, which are difficult to pinpoint and often spread over a larger area.
Question 15
the large sewer in rom that was completed around 500 bc was called___
Correct Answer
cloaca maxima
Rationale:
The correct answer is "cloaca maxima" because it was a large underground sewage tunnel in ancient Rome that collected and directed waste
away from the city's central areas. This infrastructure was built around 500 BC in the Roman Kingdom period to improve sanitation and public
health in the city.
Trusted by thousands of students and professionals worldwide Page 4 of 40
