CLASS D WATER OPERATOR LICENSE
EXAM TCEQ EXAM 2026 QUESTIONS
AND CORRECT ANSWERS (100%
CORRECT VERIFIED ANSWERS)
Sample Point, Check the Chlorine Residual, then Resample
within 24 Days of Notification. - Anwser//False (If a routine
sample is total coliform-positive, the PWS should flush the
positive sample point, check the chlorine residual, then
resample within *24 hrs* of notification) To Prevent the
Formation of THMS in Surface Water, Chlorine is Combined
with _____ Forming Chloramine, Combined Chlorine Residual. -
Anwser//Ammonia If there is no chlorine residual at a faucet,
do not sample, flush longer. - Anwser//Residual chlorine should
be present for sampling T/F: All repeat samples must be
collected on successive days. - Anwser//False (Collect all repeat
samples on the same day) In the event of distribution pressure
below 20 psi, water outages, repeated bad samples or chlorine
residual below minimum, special precautions must be
instituted. - Anwser//Pressure/water/chlorine Get the sample
to the lab within 30 hours or it will be rejected. - Anwser//Time
limit for BacT samples At 0.8 - 1.0 mg/L, fluoride reduces dental
cavities, but in higher doses (>2.0 mg/L) can cause mottling of
teeth over time. - Anwser//Fluoride effects on teeth T/F: One
by-product of chlorinated drinking water is trihalomethane, a
suspected carcinogen. - Anwser//True (Trihalomethane is a by-
product) Repeat samples must be taken at the positive point
within 5 connections upstream and within 5 connections
downstream. - Anwser//Sampling locations for repeat samples
T/F: If you do not fill out the submission form completely, you
risk losing credit for the sample. - Anwser//True (Submission
form completion is important) T/F: The presence of fecal
,coliform in a water sample indicates fecal contamination from a
human or warm-blooded animal. - Anwser//True (Sign of fecal
contamination) The purpose of the sample site plan is to assure
bacteriological samples are collected from active service
connections which are representative of the distribution
system. - Anwser//Importance of sample site plan True/False:
Keeping the sample in ice or in a cooler prior to and during lab
transport is important because heat stimulates bacterial
growth. - Anwser//True What is the action level for lead and
copper in mg/L? - Anwser//Lead: 0.015 mg/L, Copper: 1.3 mg/L
True/False: Low doses of heavy metals like lead and copper can
cause damage to the central nervous system over time. -
Anwser//True What group of bacteria is used to indicate the
possible presence of a pathogen? - Anwser//Coliform What is
the term for the destruction of disease-causing microorganisms?
- Anwser//Pathogens At room temperature, what form is
chlorine in and how does its weight compare to air? -
Anwser//Chlorine is a greenish-yellow gas that is 2.5 times
heavier than air. What must be kept in stock for disinfecting
new water lines as required by the State? - Anwser//Calcium
hypochlorite True/False: Hypochlorinators consist of a mixing
tank and chemical solution feed pump. - Anwser//True When
chlorine gas is used, what type of breathing apparatus must be
readily accessible outside the chlorinator room? - Anwser//A
full-face self-contained breathing apparatus (SCBA) or supplied
air respirator that meets OSHA standards True/False: Is it
mandatory for all public water systems to have chlorination
facilities? - Anwser//True If chlorine enters the eyes, what
should be done? - Anwser//Flush with running cool water for at
least 15 minutes and seek medical attention. What approval
must liquid bleach used in PWS have? - Anwser//NSF approved
What are the primary components of a gas feed chlorinator? -
Anwser//False (injector, vacuum regulator, flowrate controller,
rotameter- *not a mixing tank*) What is the maximum
sustained gas withdrawal rate for pressure transmission 150 lb
, cylinders? - Anwser//40 lbs/day What forms of chlorine do
utility operators use? - Anwser//True (1) pure chlorine in liquid
or gas state, (2) bleach solutions, (3) granular/tablet
compounds What should be done if chlorine contacts the skin?
- Anwser//False (15 minutes) What type of residual is
hypochlorous acid? - Anwser//Free residual What should be
done if a major chlorine leak occurs? - Anwser//Call the
supplier and TCEQ What does the rotameter indicate the feed
rate in? - Anwser//Pounds per day Does chlorine react with
hydrocarbons producing heat or fire? - Anwser//True
Chlorinator Rooms Facilities - Anwser//Facilities for
determining daily disinfectant amount Dosage of Chlorine -
Anwser//False (parts per million) DPD Reaction Color -
Anwser//Red Residual Chlorine - Anwser//True (Dosage:
amount put in system, Demand: amount used, Residual:
amount left) TCEQ Raw Water Sampling - Anwser//True
Permeability Definition - Anwser//Ability to transmit water
through aquifer Drawdown Definition - Anwser//True Artesian
Aquifer Wells - Anwser//Deep wells Well Screen Purpose -
Anwser//Prevents sand from entering well Corrosive
Groundwater Treatment - Anwser//True (add alkalinity to
adjust pH) True or False: The Line Shaft Turbine is driven by a
motor located above the pump at ground level. - Anwser//True
True or False: Well casing supports the bore hole and helps
protect the aquifer from contamination. - Anwser//True True
or False: The State requires a physical and chemical analysis of
the water after 24 hours of pumping. - Anwser//False (36 hours)
True or False: Some artesian aquifer recharge areas (outcrop)
are located many miles away from the well development site. -
Anwser//True (Artesian Wells can be recharged from many
miles away) A BacT sample, taken from a newly constructed
well, on how many consecutive days, must show negative
results? - Anwser//3 Water in an aquifer is called _____ water.
- Anwser//ground True or False: A sanitary control easement
covering land within 1500 feet of a public well must be
EXAM TCEQ EXAM 2026 QUESTIONS
AND CORRECT ANSWERS (100%
CORRECT VERIFIED ANSWERS)
Sample Point, Check the Chlorine Residual, then Resample
within 24 Days of Notification. - Anwser//False (If a routine
sample is total coliform-positive, the PWS should flush the
positive sample point, check the chlorine residual, then
resample within *24 hrs* of notification) To Prevent the
Formation of THMS in Surface Water, Chlorine is Combined
with _____ Forming Chloramine, Combined Chlorine Residual. -
Anwser//Ammonia If there is no chlorine residual at a faucet,
do not sample, flush longer. - Anwser//Residual chlorine should
be present for sampling T/F: All repeat samples must be
collected on successive days. - Anwser//False (Collect all repeat
samples on the same day) In the event of distribution pressure
below 20 psi, water outages, repeated bad samples or chlorine
residual below minimum, special precautions must be
instituted. - Anwser//Pressure/water/chlorine Get the sample
to the lab within 30 hours or it will be rejected. - Anwser//Time
limit for BacT samples At 0.8 - 1.0 mg/L, fluoride reduces dental
cavities, but in higher doses (>2.0 mg/L) can cause mottling of
teeth over time. - Anwser//Fluoride effects on teeth T/F: One
by-product of chlorinated drinking water is trihalomethane, a
suspected carcinogen. - Anwser//True (Trihalomethane is a by-
product) Repeat samples must be taken at the positive point
within 5 connections upstream and within 5 connections
downstream. - Anwser//Sampling locations for repeat samples
T/F: If you do not fill out the submission form completely, you
risk losing credit for the sample. - Anwser//True (Submission
form completion is important) T/F: The presence of fecal
,coliform in a water sample indicates fecal contamination from a
human or warm-blooded animal. - Anwser//True (Sign of fecal
contamination) The purpose of the sample site plan is to assure
bacteriological samples are collected from active service
connections which are representative of the distribution
system. - Anwser//Importance of sample site plan True/False:
Keeping the sample in ice or in a cooler prior to and during lab
transport is important because heat stimulates bacterial
growth. - Anwser//True What is the action level for lead and
copper in mg/L? - Anwser//Lead: 0.015 mg/L, Copper: 1.3 mg/L
True/False: Low doses of heavy metals like lead and copper can
cause damage to the central nervous system over time. -
Anwser//True What group of bacteria is used to indicate the
possible presence of a pathogen? - Anwser//Coliform What is
the term for the destruction of disease-causing microorganisms?
- Anwser//Pathogens At room temperature, what form is
chlorine in and how does its weight compare to air? -
Anwser//Chlorine is a greenish-yellow gas that is 2.5 times
heavier than air. What must be kept in stock for disinfecting
new water lines as required by the State? - Anwser//Calcium
hypochlorite True/False: Hypochlorinators consist of a mixing
tank and chemical solution feed pump. - Anwser//True When
chlorine gas is used, what type of breathing apparatus must be
readily accessible outside the chlorinator room? - Anwser//A
full-face self-contained breathing apparatus (SCBA) or supplied
air respirator that meets OSHA standards True/False: Is it
mandatory for all public water systems to have chlorination
facilities? - Anwser//True If chlorine enters the eyes, what
should be done? - Anwser//Flush with running cool water for at
least 15 minutes and seek medical attention. What approval
must liquid bleach used in PWS have? - Anwser//NSF approved
What are the primary components of a gas feed chlorinator? -
Anwser//False (injector, vacuum regulator, flowrate controller,
rotameter- *not a mixing tank*) What is the maximum
sustained gas withdrawal rate for pressure transmission 150 lb
, cylinders? - Anwser//40 lbs/day What forms of chlorine do
utility operators use? - Anwser//True (1) pure chlorine in liquid
or gas state, (2) bleach solutions, (3) granular/tablet
compounds What should be done if chlorine contacts the skin?
- Anwser//False (15 minutes) What type of residual is
hypochlorous acid? - Anwser//Free residual What should be
done if a major chlorine leak occurs? - Anwser//Call the
supplier and TCEQ What does the rotameter indicate the feed
rate in? - Anwser//Pounds per day Does chlorine react with
hydrocarbons producing heat or fire? - Anwser//True
Chlorinator Rooms Facilities - Anwser//Facilities for
determining daily disinfectant amount Dosage of Chlorine -
Anwser//False (parts per million) DPD Reaction Color -
Anwser//Red Residual Chlorine - Anwser//True (Dosage:
amount put in system, Demand: amount used, Residual:
amount left) TCEQ Raw Water Sampling - Anwser//True
Permeability Definition - Anwser//Ability to transmit water
through aquifer Drawdown Definition - Anwser//True Artesian
Aquifer Wells - Anwser//Deep wells Well Screen Purpose -
Anwser//Prevents sand from entering well Corrosive
Groundwater Treatment - Anwser//True (add alkalinity to
adjust pH) True or False: The Line Shaft Turbine is driven by a
motor located above the pump at ground level. - Anwser//True
True or False: Well casing supports the bore hole and helps
protect the aquifer from contamination. - Anwser//True True
or False: The State requires a physical and chemical analysis of
the water after 24 hours of pumping. - Anwser//False (36 hours)
True or False: Some artesian aquifer recharge areas (outcrop)
are located many miles away from the well development site. -
Anwser//True (Artesian Wells can be recharged from many
miles away) A BacT sample, taken from a newly constructed
well, on how many consecutive days, must show negative
results? - Anwser//3 Water in an aquifer is called _____ water.
- Anwser//ground True or False: A sanitary control easement
covering land within 1500 feet of a public well must be
