1|Page
Washington Water Distribution Operator Certification
Examination||Verified Exam!!! — Level 1 Exam
Practice Questions And Correct Answers (Verified
Answers) Plus Rationale 2026/2027 Q&A| Instant
Download Pdf
when digging a trench for a water main, the person
qualified to choose the correct type of shoring required for
the trench is the
a) chief operator of the system
b) certified operator
c) competent person at the site
d) operator who will be working in the trench - Answer-c)
competent person at the site
which of the following is a problem that may occur if the
tap to a customer service line is placed at the top of the
water main ?
a) the customers line will be subject to corrosion
b) the customer may get sediment or dirt in their service
line
c) the water pressure will be too high
,2|Page
d) the customer may get air in their service line - Answer-
D) the customer may get air in their service line
one advantage of "hot or wet tapping" over "dry tapping" a
water line is that
a) it is less dangerous because it is not done under
pressure
b) no specialized tools are required
c) there is less chance of contamination entering the water
main
d) all of the above - Answer-c) there is less chance of
contamination entering the water main
which type of corrosion is caused by connecting dissimilar
metal fitting in a water system ?
a) caustic corrosion
b) galvanic corrosion
c) oxygen corrosion
d) tubercular corrosion - Answer-b) galvanic corrosion
which of the following can be used to repair a cracked
water main?
,3|Page
a) flanged adapter
b) split sleeve
c) tapered screw plug
d) cast coupling - Answer-b) split sleeve
which of the following is one method of reducing friction
loss in a water pipe?
a) increasing the velocity of the water
b) removing incrustation from the pipe
c) adding chlorine to the water
d) reducing the hardness of the water - Answer-b)
removing incrustation from the pipe
What is the term for the deposition of calcium carbonate
on the inside of a water pipe?
a ) biofilm build up
b ) scale formation
c ) corrosion - Answer-b) scale formation
when comparing water main pipe, what does a high "C
value indicate?
a) the pipe is smooth inside
, 4|Page
b) the pipe is rough inside
c) the pipe is brittle and needs to be replaced
d) the pipe has a high tensile strength - Answer-a) the pipe
is smooth inside
A device used to maintain electrical continuity between
household plumbing and service lines is known as a
a) jumper
b) sacrificial anode
c) tracer line
d) coupon - Answer-a) jumper
Turbulence due to the velocity of flowing water, roughness
of the pipe , or restrictions caused fittings can result in
a) back siphonage
b) scale formation
c) increased head pressure
d) friction loss - Answer-d ) friction loss
which of the following type of pipe is most resistant to
corrosion ?
Washington Water Distribution Operator Certification
Examination||Verified Exam!!! — Level 1 Exam
Practice Questions And Correct Answers (Verified
Answers) Plus Rationale 2026/2027 Q&A| Instant
Download Pdf
when digging a trench for a water main, the person
qualified to choose the correct type of shoring required for
the trench is the
a) chief operator of the system
b) certified operator
c) competent person at the site
d) operator who will be working in the trench - Answer-c)
competent person at the site
which of the following is a problem that may occur if the
tap to a customer service line is placed at the top of the
water main ?
a) the customers line will be subject to corrosion
b) the customer may get sediment or dirt in their service
line
c) the water pressure will be too high
,2|Page
d) the customer may get air in their service line - Answer-
D) the customer may get air in their service line
one advantage of "hot or wet tapping" over "dry tapping" a
water line is that
a) it is less dangerous because it is not done under
pressure
b) no specialized tools are required
c) there is less chance of contamination entering the water
main
d) all of the above - Answer-c) there is less chance of
contamination entering the water main
which type of corrosion is caused by connecting dissimilar
metal fitting in a water system ?
a) caustic corrosion
b) galvanic corrosion
c) oxygen corrosion
d) tubercular corrosion - Answer-b) galvanic corrosion
which of the following can be used to repair a cracked
water main?
,3|Page
a) flanged adapter
b) split sleeve
c) tapered screw plug
d) cast coupling - Answer-b) split sleeve
which of the following is one method of reducing friction
loss in a water pipe?
a) increasing the velocity of the water
b) removing incrustation from the pipe
c) adding chlorine to the water
d) reducing the hardness of the water - Answer-b)
removing incrustation from the pipe
What is the term for the deposition of calcium carbonate
on the inside of a water pipe?
a ) biofilm build up
b ) scale formation
c ) corrosion - Answer-b) scale formation
when comparing water main pipe, what does a high "C
value indicate?
a) the pipe is smooth inside
, 4|Page
b) the pipe is rough inside
c) the pipe is brittle and needs to be replaced
d) the pipe has a high tensile strength - Answer-a) the pipe
is smooth inside
A device used to maintain electrical continuity between
household plumbing and service lines is known as a
a) jumper
b) sacrificial anode
c) tracer line
d) coupon - Answer-a) jumper
Turbulence due to the velocity of flowing water, roughness
of the pipe , or restrictions caused fittings can result in
a) back siphonage
b) scale formation
c) increased head pressure
d) friction loss - Answer-d ) friction loss
which of the following type of pipe is most resistant to
corrosion ?
