ILLINOIS CLASS D WATER LICENSE TEST 2025 NEWEST ACTUAL EXAM
CURRENTLY TESTING COMPLETE EXAM
Two Towers are both 125 feet high, when full, contain 122 feet of water. Tower 1 holds 150,000 gallons.
Tower 2 holds 500,000 gallons. Each has a pressure gauge at the base. Which will register the most
pressure in psi? - ((answer))Both will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base - ((answer))51.1
psi
What is the definition of potable water - ((answer))Water that does not contain objectable pollution,
contamination, or infective agents and is considered safe for drinking
What is the first item used when installing a service line to a customer? - ((answer))Corporation stop
If a meter to a residence is located in the basement what should be located between the water main
and the house - ((answer))curb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in recording
actual water used - ((answer))Decreases
To isolate part of a distribution system what type of valve is commonly used? - ((answer))Gate valve
Trihalomethanes (THMs) are caused by? - ((answer))Reaction of chlorinated water with numeric
materials found in surface water sources
The longer the contact time water and chlorine residuals enjoy the ________ the THM level will
probably be - ((answer))Higher
THM's should be eliminated from finished water because they cause ? - ((answer))Cancer
, The maximum contaminant level for THM's is? - ((answer)).080 mg/l
When collecting THM samples one sample must be taken at a site where the water has been in the
distribution system the longest time - ((answer))True
An applicant for a class d test who has graduated high school but has no approved training credits must
have ____________ "hands on" experience - ((answer))6 months
What type of water main is most likely to become contaminated from gasoline saturated soil -
((answer))PVC
What type of materials must not be used as backfill for water mains? - ((answer))Cinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease - ((answer))10
A boil order must be issued if systems pressure drops below 20 psi or if contaminated of any part of the
system is suspected. Why? - ((answer))It is a regulation of the IEPA, and to protect the health of water
consumers
A boil order should be issued for? - ((answer))Until further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order because
________________? - ((answer))It's a state regulation
The "C" factor of a pipe is _______________? - ((answer))The smoothness of the interior of a pipe
The higher the "C" factor of a pipe the _____________ the pipe and the greater the carrying capacity of
the pipe - ((answer))Smoother
A distribution system that is "looped" instead of having dead ends will help prevent - ((answer))Tastes
and odors, "dirty" water, and chlorine depletion
CURRENTLY TESTING COMPLETE EXAM
Two Towers are both 125 feet high, when full, contain 122 feet of water. Tower 1 holds 150,000 gallons.
Tower 2 holds 500,000 gallons. Each has a pressure gauge at the base. Which will register the most
pressure in psi? - ((answer))Both will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base - ((answer))51.1
psi
What is the definition of potable water - ((answer))Water that does not contain objectable pollution,
contamination, or infective agents and is considered safe for drinking
What is the first item used when installing a service line to a customer? - ((answer))Corporation stop
If a meter to a residence is located in the basement what should be located between the water main
and the house - ((answer))curb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in recording
actual water used - ((answer))Decreases
To isolate part of a distribution system what type of valve is commonly used? - ((answer))Gate valve
Trihalomethanes (THMs) are caused by? - ((answer))Reaction of chlorinated water with numeric
materials found in surface water sources
The longer the contact time water and chlorine residuals enjoy the ________ the THM level will
probably be - ((answer))Higher
THM's should be eliminated from finished water because they cause ? - ((answer))Cancer
, The maximum contaminant level for THM's is? - ((answer)).080 mg/l
When collecting THM samples one sample must be taken at a site where the water has been in the
distribution system the longest time - ((answer))True
An applicant for a class d test who has graduated high school but has no approved training credits must
have ____________ "hands on" experience - ((answer))6 months
What type of water main is most likely to become contaminated from gasoline saturated soil -
((answer))PVC
What type of materials must not be used as backfill for water mains? - ((answer))Cinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease - ((answer))10
A boil order must be issued if systems pressure drops below 20 psi or if contaminated of any part of the
system is suspected. Why? - ((answer))It is a regulation of the IEPA, and to protect the health of water
consumers
A boil order should be issued for? - ((answer))Until further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order because
________________? - ((answer))It's a state regulation
The "C" factor of a pipe is _______________? - ((answer))The smoothness of the interior of a pipe
The higher the "C" factor of a pipe the _____________ the pipe and the greater the carrying capacity of
the pipe - ((answer))Smoother
A distribution system that is "looped" instead of having dead ends will help prevent - ((answer))Tastes
and odors, "dirty" water, and chlorine depletion
