Class D Water License EXAMINATION SET
2026 SOLVED QUESTIONS GRADED A+
● Corporation Stop. Answer: What is the first item used when installing
a service line to a customer?
● Gate valve. Answer: To isolate a part of a distribution system what
type of valve is commonly used?
● Reaction of chlorinated water with organic materials found in any
water sources. Answer: Trihalomethanes. (THM) are caused by?
● Higher. Answer: The longer the contact time water and chlorine
residuals enjoy the _______________ the THM level will probably be?
● Cancer. Answer: THM's should be eliminated from finished water
because they cause ______________?
● .09 mg/l. Answer: The maximum contaminate level (MCL) for THM's
is ___________?
● True. Answer: True or false? When collection THM samples, one as,-
lie must be taken at the site where the water has been in the distribution
system the longest?
, ● PVC. Answer: What type of water main is most likely to become
contaminated from gasoline saturated soil?
● Cinders. Answer: What type of materials must be used as backfill for
water mains?
● 10. Answer: Nitrate in levels above __________________ mg/l can
cause "blue baby" disease?
● Until further notice. Answer: A boil order should be issued for how
long?
● It is a regulation of the EPA and to protect the health of the water
comsumers. Answer: A boil order must be issued if system pressure
drops below 20 psi or if contamination of any part of the system is
suspected. Why?
● It's a state regulation. Answer: Upon the issuance of a boil order the
IEPA regional office should be notified of the order because
____________?
● The smoothness of the interior of the pipe. Answer: The "C" factor of
a pipe is?
2026 SOLVED QUESTIONS GRADED A+
● Corporation Stop. Answer: What is the first item used when installing
a service line to a customer?
● Gate valve. Answer: To isolate a part of a distribution system what
type of valve is commonly used?
● Reaction of chlorinated water with organic materials found in any
water sources. Answer: Trihalomethanes. (THM) are caused by?
● Higher. Answer: The longer the contact time water and chlorine
residuals enjoy the _______________ the THM level will probably be?
● Cancer. Answer: THM's should be eliminated from finished water
because they cause ______________?
● .09 mg/l. Answer: The maximum contaminate level (MCL) for THM's
is ___________?
● True. Answer: True or false? When collection THM samples, one as,-
lie must be taken at the site where the water has been in the distribution
system the longest?
, ● PVC. Answer: What type of water main is most likely to become
contaminated from gasoline saturated soil?
● Cinders. Answer: What type of materials must be used as backfill for
water mains?
● 10. Answer: Nitrate in levels above __________________ mg/l can
cause "blue baby" disease?
● Until further notice. Answer: A boil order should be issued for how
long?
● It is a regulation of the EPA and to protect the health of the water
comsumers. Answer: A boil order must be issued if system pressure
drops below 20 psi or if contamination of any part of the system is
suspected. Why?
● It's a state regulation. Answer: Upon the issuance of a boil order the
IEPA regional office should be notified of the order because
____________?
● The smoothness of the interior of the pipe. Answer: The "C" factor of
a pipe is?
