©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Class D Water Operator License Exam
TCEQ Questions And Answers Updated 2024
T/F: In Texas, about 75% of all water is used for commercial, industrial, or agricultural
purposes. - answer✔True
Water covers approximately ________ of Earth's surface. - answer✔71%
Drought is an extended period when a region receives a deficiency in its ________ water
supply. - answer✔atmospheric, ground, or surface
T/F: Only about 1 gallon of tap water per person/day is used for drinking and cooking -
answer✔True
Excluding outside water use, the average household uses about _______ gallons of water
per month for inside use - answer✔2,000
T/F: Only 3% of all the fresh water on earth can be easily accessed for use. - answer✔False
(only 1%)
T/F: In 1978, the Texas Department of Health (TDH) assumed primacy over the Safe
Drinking Water Act from the EPA. - answer✔True
T/F: PWS officials should be pro-active in their approach to terrorism. - answer✔True
_________ permits the owner of a well to pump as much water as desired, even if the water
is drained from beneath the land of others. - answer✔Rule of Capture
In Texas, agricultural water demand accounts for about ___% of the total water used. -
answer✔57%
T/F: An example of a non-transient non-community PWS is a rural school. - answer✔True
Monitoring average and maximum daily water ______ enables us to plan ahead for growth. -
answer✔Demand
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
T/F: The Safe Drinking Water Act sets standards for drinking water including physical,
chemical, bacteriological, and radiological characteristics. - answer✔True
"Potable" means water is safe to drink and has a measurable chlorine ________. -
answer✔Residual
The plant operator is responsible for a sufficient supply of safe and ________ drinking water.
- answer✔Palatable
T/F: The Texas State Board of Fire Insurance requires utilities that provide fire protection to
have a minimum amount of water available based on 30 gals per person per day. -
answer✔False (130 gals per person per day)
T/F: The primary state regulator of water utilities is the TCEQ. - answer✔True
T/F: All community and non-transient non-community PWS, regardless of source of water,
must be under the supervision of a licensed water works operator. - answer✔True
Meter readers bring in operating revenue and profoundly impact _____ relations. -
answer✔Public
The federal regulator of drinking water is the _____. - answer✔EPA
T/F: Duties of distribution operator include repairing leaks, making taps, flushing mains,
and taking radiological samples. - answer✔False (Repair leaks, Make taps, Flush mains,
Operate pumps, Take *bacteriological* samples)
A service area has 1000 service connections. What can we estimate the population of this
service area to be? - answer✔3,000 (multiply connections x 3)
T/F: The State must be notified after an existing facility is changed or after construction of a
new facility. - answer✔False (must notify *before*)
T/F: A Class "D" license is valid for 2 years at ground and purchase water systems with 250
connections or less. - answer✔False (3 years)
T/F: The physical characteristics of water are color, taste, odor, temperature, and turbidity.
- answer✔True
An alkaline or basic solution has a pH greater than ____. - answer✔7
T/F: The terms mg/L and ppm are not interchangeable. - answer✔False (they are
interchangeable)
Suspended solids in water cannot be filtered out. - answer✔False (they can)
2|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Solids, water hardness, pH and gases are ____ characteristics. - answer✔Chemical
T/F: There are 2 hydrogen atoms and 1 oxygen atom in each water molecule. -
answer✔True
T/F: The State recommends a water pH of less than 7 to be maintained at all time. -
answer✔False (The state recommends a pH slightly greater than 7 and for the water to be
non-corrosive.)
T/F: Taste and odor can come from organisms such as vegetation, bacteria, and algae, and
from certain chemicals and metals. - answer✔True
T/F: The deeper the well, the warmer the water. - answer✔True
T/F: The threshold odor number (TON) relates to the number of dilutions needed for the
water to be tasteless. - answer✔False (It reflects the number of dilutions needed for water
sample to be *odorless*)
One part per million or 1 mg/L means that for every ____ pounds of water there is one
pound of material in it. - answer✔1 million
The State requires filtered water to be equal to or less than ____ turbidity units in at least
95% of the monthly samples. - answer✔0.3
The State recommends a TON of ___ or less. - answer✔3
T/F: The State recommends 20 color units or less for a quality water. - answer✔False (The
state recommends 15 units of color or less for drinking water.)
T/F: Examples of inorganic matter found in water include rock, sand, metals, and minerals.
- answer✔True
T/F: The red color caused by iron is an example of suspended or apparent color and it can
be removed by filtration. - answer✔True
Excessive calcium and _____ are the primary cause of hardness in water. -
answer✔Magnesium
T/F: The State recommends a maximum total dissolved solids content of 500 mg/L -
answer✔False (The state recommends that TDS not exceed 1000 mg/L)
There are 3 common gases found in water: methane, carbon dioxide, and __________
___________. - answer✔hydrogen sulfide
3|Page
ALL RIGHTS RESERVED.
Class D Water Operator License Exam
TCEQ Questions And Answers Updated 2024
T/F: In Texas, about 75% of all water is used for commercial, industrial, or agricultural
purposes. - answer✔True
Water covers approximately ________ of Earth's surface. - answer✔71%
Drought is an extended period when a region receives a deficiency in its ________ water
supply. - answer✔atmospheric, ground, or surface
T/F: Only about 1 gallon of tap water per person/day is used for drinking and cooking -
answer✔True
Excluding outside water use, the average household uses about _______ gallons of water
per month for inside use - answer✔2,000
T/F: Only 3% of all the fresh water on earth can be easily accessed for use. - answer✔False
(only 1%)
T/F: In 1978, the Texas Department of Health (TDH) assumed primacy over the Safe
Drinking Water Act from the EPA. - answer✔True
T/F: PWS officials should be pro-active in their approach to terrorism. - answer✔True
_________ permits the owner of a well to pump as much water as desired, even if the water
is drained from beneath the land of others. - answer✔Rule of Capture
In Texas, agricultural water demand accounts for about ___% of the total water used. -
answer✔57%
T/F: An example of a non-transient non-community PWS is a rural school. - answer✔True
Monitoring average and maximum daily water ______ enables us to plan ahead for growth. -
answer✔Demand
1|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
T/F: The Safe Drinking Water Act sets standards for drinking water including physical,
chemical, bacteriological, and radiological characteristics. - answer✔True
"Potable" means water is safe to drink and has a measurable chlorine ________. -
answer✔Residual
The plant operator is responsible for a sufficient supply of safe and ________ drinking water.
- answer✔Palatable
T/F: The Texas State Board of Fire Insurance requires utilities that provide fire protection to
have a minimum amount of water available based on 30 gals per person per day. -
answer✔False (130 gals per person per day)
T/F: The primary state regulator of water utilities is the TCEQ. - answer✔True
T/F: All community and non-transient non-community PWS, regardless of source of water,
must be under the supervision of a licensed water works operator. - answer✔True
Meter readers bring in operating revenue and profoundly impact _____ relations. -
answer✔Public
The federal regulator of drinking water is the _____. - answer✔EPA
T/F: Duties of distribution operator include repairing leaks, making taps, flushing mains,
and taking radiological samples. - answer✔False (Repair leaks, Make taps, Flush mains,
Operate pumps, Take *bacteriological* samples)
A service area has 1000 service connections. What can we estimate the population of this
service area to be? - answer✔3,000 (multiply connections x 3)
T/F: The State must be notified after an existing facility is changed or after construction of a
new facility. - answer✔False (must notify *before*)
T/F: A Class "D" license is valid for 2 years at ground and purchase water systems with 250
connections or less. - answer✔False (3 years)
T/F: The physical characteristics of water are color, taste, odor, temperature, and turbidity.
- answer✔True
An alkaline or basic solution has a pH greater than ____. - answer✔7
T/F: The terms mg/L and ppm are not interchangeable. - answer✔False (they are
interchangeable)
Suspended solids in water cannot be filtered out. - answer✔False (they can)
2|Page
, ©THESTAR EXAM SOLUTIONS 2024/2025
ALL RIGHTS RESERVED.
Solids, water hardness, pH and gases are ____ characteristics. - answer✔Chemical
T/F: There are 2 hydrogen atoms and 1 oxygen atom in each water molecule. -
answer✔True
T/F: The State recommends a water pH of less than 7 to be maintained at all time. -
answer✔False (The state recommends a pH slightly greater than 7 and for the water to be
non-corrosive.)
T/F: Taste and odor can come from organisms such as vegetation, bacteria, and algae, and
from certain chemicals and metals. - answer✔True
T/F: The deeper the well, the warmer the water. - answer✔True
T/F: The threshold odor number (TON) relates to the number of dilutions needed for the
water to be tasteless. - answer✔False (It reflects the number of dilutions needed for water
sample to be *odorless*)
One part per million or 1 mg/L means that for every ____ pounds of water there is one
pound of material in it. - answer✔1 million
The State requires filtered water to be equal to or less than ____ turbidity units in at least
95% of the monthly samples. - answer✔0.3
The State recommends a TON of ___ or less. - answer✔3
T/F: The State recommends 20 color units or less for a quality water. - answer✔False (The
state recommends 15 units of color or less for drinking water.)
T/F: Examples of inorganic matter found in water include rock, sand, metals, and minerals.
- answer✔True
T/F: The red color caused by iron is an example of suspended or apparent color and it can
be removed by filtration. - answer✔True
Excessive calcium and _____ are the primary cause of hardness in water. -
answer✔Magnesium
T/F: The State recommends a maximum total dissolved solids content of 500 mg/L -
answer✔False (The state recommends that TDS not exceed 1000 mg/L)
There are 3 common gases found in water: methane, carbon dioxide, and __________
___________. - answer✔hydrogen sulfide
3|Page
