ILLINOIS CLASS D WATER LICENSE
EXAM QUESTIONS AND ANSWERS
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? -ANSBoth will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base -
ANS51.1 psi
What is the definition of potable water -ANSWater 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? -
ANSCorporation stop
If a meter to a residence is located in the basement what should be located between the
water main and the house -ANScurb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter
__________ in recording actual water used -ANSDecreases
To isolate part of a distribution system what type of valve is commonly used? -ANSGate
valve
Trihalomethanes (THMs) are caused by? -ANSReaction 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 -ANSHigher
THM's should be eliminated from finished water because they cause ? -ANSCancer
The maximum contaminant level for THM's is? -ANS.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 -ANSTrue
An applicant for a class d test who has graduated high school but has no approved
training credits must have ____________ "hands on" experience -ANS6 months
, What type of water main is most likely to become contaminated from gasoline saturated
soil -ANSPVC
What type of materials must not be used as backfill for water mains? -ANSCinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease -ANS10
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? -ANSIt is a regulation of the IEPA, and to
protect the health of water consumers
A boil order should be issued for? -ANSUntil further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order
because ________________? -ANSIt's a state regulation
The "C" factor of a pipe is _______________? -ANSThe 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 -ANSSmoother
A distribution system that is "looped" instead of having dead ends will help prevent -
ANSTastes and odors, "dirty" water, and chlorine depletion
Chlorine tablets (calcium hypochlorite) should be used for the disinfection of newly
installed water main. These tablets should be ________________ -ANSGlued to the top
of each section
What is the definition of a water main? -ANSAny line that passes one property to reach
another parcel of property
What is the minimum size of a water main required by the IEPA -ANS4 inches in
diameter
Is a construction permit from the IEPA permit section required for the installation of a
water main? -ANSYes
Is a construction permit from the IEPA permit section required for the installation of a
water service? -ANSNo
A three-quarter inch service line is tapped on a water main. The corporation stop should
be installed__________________ -ANSAt an angle between the top and side of the
main
EXAM QUESTIONS AND ANSWERS
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? -ANSBoth will be equal
If the water level in tower 1 is 118 feet what will the pressure reading be at the base -
ANS51.1 psi
What is the definition of potable water -ANSWater 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? -
ANSCorporation stop
If a meter to a residence is located in the basement what should be located between the
water main and the house -ANScurb stop
A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter
__________ in recording actual water used -ANSDecreases
To isolate part of a distribution system what type of valve is commonly used? -ANSGate
valve
Trihalomethanes (THMs) are caused by? -ANSReaction 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 -ANSHigher
THM's should be eliminated from finished water because they cause ? -ANSCancer
The maximum contaminant level for THM's is? -ANS.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 -ANSTrue
An applicant for a class d test who has graduated high school but has no approved
training credits must have ____________ "hands on" experience -ANS6 months
, What type of water main is most likely to become contaminated from gasoline saturated
soil -ANSPVC
What type of materials must not be used as backfill for water mains? -ANSCinders
Nitrate in levels above _________ mg/L can cause "blue baby" disease -ANS10
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? -ANSIt is a regulation of the IEPA, and to
protect the health of water consumers
A boil order should be issued for? -ANSUntil further notice
Upon the issuance of a boil order the IEPA regional office should be notified of the order
because ________________? -ANSIt's a state regulation
The "C" factor of a pipe is _______________? -ANSThe 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 -ANSSmoother
A distribution system that is "looped" instead of having dead ends will help prevent -
ANSTastes and odors, "dirty" water, and chlorine depletion
Chlorine tablets (calcium hypochlorite) should be used for the disinfection of newly
installed water main. These tablets should be ________________ -ANSGlued to the top
of each section
What is the definition of a water main? -ANSAny line that passes one property to reach
another parcel of property
What is the minimum size of a water main required by the IEPA -ANS4 inches in
diameter
Is a construction permit from the IEPA permit section required for the installation of a
water main? -ANSYes
Is a construction permit from the IEPA permit section required for the installation of a
water service? -ANSNo
A three-quarter inch service line is tapped on a water main. The corporation stop should
be installed__________________ -ANSAt an angle between the top and side of the
main
