ILLINOIS CLASS D WATER LICENSE EXAM (ACTUAL
EXAM 2025) | ALL QUESTIONS AND CORRECT
ANSWERS | VERIFIED ANSWERS | ALREADY GRADED
A+ | LATEST 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
EXAM 2025) | ALL QUESTIONS AND CORRECT
ANSWERS | VERIFIED ANSWERS | ALREADY GRADED
A+ | LATEST 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
