D1-D4 Water Operator Prep Exam Newest 2026
Questions and Correct Detailed Answers Already
Graded A+
What type of fire hydrant has no main valve, but has a separate valve for each
nozzle? - CORRECT ANSWER-Wet-Barrel
What type of pipe joint is used in an area with hills or earthquakes to make sure
joints do not sperate? - CORRECT ANSWER-Restrain Joint
What is atmospheric pressure at sea level? - CORRECT ANSWER-14.7 pounds
per square inch
Water main cleaning methods include. - CORRECT ANSWER-Swabbing &
Pigging
What can be devolved by measuring the pressure along a pipeline? - CORRECT
ANSWER-The Hydraulic Grade
,On a brand new pump, when should the first oil change be done? - CORRECT
ANSWER-After One Month of Operation
What gas can cause lung and skin irritation? - CORRECT ANSWER-Chlorine Gas
Water mains that are 12" or less in diameter should have isolation valves that are
located not more than how many feet between each other? - CORRECT
ANSWER-1,000'
On a venturi meter the up or down stream pressure is compared to the pressure?
- CORRECT ANSWER-The throat of the venturi
What agency mandates the language and methods for public notification? -
CORRECT ANSWER-U.S. Environmental Protection Agency (EPA)
Mechanical seals are most appropriate for pumps operating under what
condition? - CORRECT ANSWER-High Suction Head
If a body of water has high salinity and is warm, it will generally be high in
dissolved oxygen. - CORRECT ANSWER-False
, When a negative reading on the Langelier index is recorded the water is? -
CORRECT ANSWER-Corrosive
How are chloramines formed? - CORRECT ANSWER-When chlorine is
combined with aqua ammonia
What type of valve dampens water hammer? - CORRECT ANSWER-Pressure
Relief Valve
Chlorine gas expands? - CORRECT ANSWER-460 times to 1
According to the Surface Water Treatment Rule, water systems serving a
population of more than 500 persons must sample the filtered water for turbidity
every? - CORRECT ANSWER-Every Four Hours
If a pump does not hold its prime, what could be wrong? - CORRECT ANSWER-
Strain Gauge
Hard water scale is usually caused by? - CORRECT ANSWER-Calcium Carbonate
Questions and Correct Detailed Answers Already
Graded A+
What type of fire hydrant has no main valve, but has a separate valve for each
nozzle? - CORRECT ANSWER-Wet-Barrel
What type of pipe joint is used in an area with hills or earthquakes to make sure
joints do not sperate? - CORRECT ANSWER-Restrain Joint
What is atmospheric pressure at sea level? - CORRECT ANSWER-14.7 pounds
per square inch
Water main cleaning methods include. - CORRECT ANSWER-Swabbing &
Pigging
What can be devolved by measuring the pressure along a pipeline? - CORRECT
ANSWER-The Hydraulic Grade
,On a brand new pump, when should the first oil change be done? - CORRECT
ANSWER-After One Month of Operation
What gas can cause lung and skin irritation? - CORRECT ANSWER-Chlorine Gas
Water mains that are 12" or less in diameter should have isolation valves that are
located not more than how many feet between each other? - CORRECT
ANSWER-1,000'
On a venturi meter the up or down stream pressure is compared to the pressure?
- CORRECT ANSWER-The throat of the venturi
What agency mandates the language and methods for public notification? -
CORRECT ANSWER-U.S. Environmental Protection Agency (EPA)
Mechanical seals are most appropriate for pumps operating under what
condition? - CORRECT ANSWER-High Suction Head
If a body of water has high salinity and is warm, it will generally be high in
dissolved oxygen. - CORRECT ANSWER-False
, When a negative reading on the Langelier index is recorded the water is? -
CORRECT ANSWER-Corrosive
How are chloramines formed? - CORRECT ANSWER-When chlorine is
combined with aqua ammonia
What type of valve dampens water hammer? - CORRECT ANSWER-Pressure
Relief Valve
Chlorine gas expands? - CORRECT ANSWER-460 times to 1
According to the Surface Water Treatment Rule, water systems serving a
population of more than 500 persons must sample the filtered water for turbidity
every? - CORRECT ANSWER-Every Four Hours
If a pump does not hold its prime, what could be wrong? - CORRECT ANSWER-
Strain Gauge
Hard water scale is usually caused by? - CORRECT ANSWER-Calcium Carbonate
