COMMERCIAL SEPTIC SYSTEM INSTALLER EXAM UPDATED QUESTIONS AND
ANSWERS
All tanks must have: - CORRECT ANSWER✅✅2 compartments
All tanks whether pre-manufactured or constructed on site shall be constructed so that the length is
___________ compared to the width. - CORRECT ANSWER✅✅at least one and one- half (1 1/2) times...
"to the width."
Septic Tanks may be made of: - CORRECT ANSWER✅✅Concrete, Plastic, fiberglass, or other materials as
approved by the department.
Tank compartment partitions will be located: - CORRECT ANSWER✅✅Not less than two-thirds or more
than three-fourths the Length of the tank from the Inlet end.
Compartment partitions will be constructed so a pass-thru hole or slot equal to or greater than the
diameter of the inlet pipe is positioned below the liquid surface with a
_____________________________. - CORRECT ANSWER✅✅Minimum 25% to a maximum of 50% of
the total liquid depth.
Total liquid depth for larger poured-in-place tanks shall have a maximum of ______________inches -
CORRECT ANSWER✅✅66 inches
True or False: Walls and bottom of poured-in-place septic tanks must be reinforced. - CORRECT
ANSWER✅✅True
How can a Septic tank be reinforced? - CORRECT ANSWER✅✅six inch by 6 inch (6"x6") No.10 gage
welded steel reinforcing wire OR fibrous reinforcing material conforming to ASTM specifications for such
materials.
How must Tank Lids be Reinforced? - CORRECT ANSWER✅✅using three-eights steel reinforcing rods
(rebar) which shall be spaced twelve inches (12") on center each way extending a minimum of two and
one half (2 1/2") inches and a maximum of three (3") from the outside edge of the tank lid.
, In general, the tank must be able to withstand a uniform live load of ______________________ pounds
per square foot in addition to all loads to which an underground tank is normally subjected. - CORRECT
ANSWER✅✅150
True or False: Walls, bottoms, and lids of poured-in-place septic tanks should have a minimum thickness
of four inches (4"). - CORRECT ANSWER✅✅True
Tank lids shall be constructed in ______________________ pieces and shall have securable, removable
access openings located so that the inlet and outlet tees can be ________________________________.
- CORRECT ANSWER✅✅one or two,
readily accessed.
Access opening shall have a minimum of _________________ and maximum of ___________________
free space. - CORRECT ANSWER✅✅Minimum: 15"
Maximum: 24"
Tanks with more than 12 inches of cover must extend access openings to within ______ inches of the
ground surface. - CORRECT ANSWER✅✅12
All tanks shall be equipped with ________________________________ rated or equivalent tees at the
inlet and outlet ends of the tank. - CORRECT ANSWER✅✅Four inch (4") PVC, ASTM 3034
Tees shall be constructed so they extend into the liquid a minimum of ____________________ and a
maximum of __________________ of the liquid depth of the tank. - CORRECT ANSWER✅✅Min: 25%
Max: 50%
The invert of the outlet tee shall be located _______________ inches below the invert of the inlet tee. -
CORRECT ANSWER✅✅two inches
__________________ tees shall be equipped with an approved effluent filter. - CORRECT
ANSWER✅✅Outlet
ANSWERS
All tanks must have: - CORRECT ANSWER✅✅2 compartments
All tanks whether pre-manufactured or constructed on site shall be constructed so that the length is
___________ compared to the width. - CORRECT ANSWER✅✅at least one and one- half (1 1/2) times...
"to the width."
Septic Tanks may be made of: - CORRECT ANSWER✅✅Concrete, Plastic, fiberglass, or other materials as
approved by the department.
Tank compartment partitions will be located: - CORRECT ANSWER✅✅Not less than two-thirds or more
than three-fourths the Length of the tank from the Inlet end.
Compartment partitions will be constructed so a pass-thru hole or slot equal to or greater than the
diameter of the inlet pipe is positioned below the liquid surface with a
_____________________________. - CORRECT ANSWER✅✅Minimum 25% to a maximum of 50% of
the total liquid depth.
Total liquid depth for larger poured-in-place tanks shall have a maximum of ______________inches -
CORRECT ANSWER✅✅66 inches
True or False: Walls and bottom of poured-in-place septic tanks must be reinforced. - CORRECT
ANSWER✅✅True
How can a Septic tank be reinforced? - CORRECT ANSWER✅✅six inch by 6 inch (6"x6") No.10 gage
welded steel reinforcing wire OR fibrous reinforcing material conforming to ASTM specifications for such
materials.
How must Tank Lids be Reinforced? - CORRECT ANSWER✅✅using three-eights steel reinforcing rods
(rebar) which shall be spaced twelve inches (12") on center each way extending a minimum of two and
one half (2 1/2") inches and a maximum of three (3") from the outside edge of the tank lid.
, In general, the tank must be able to withstand a uniform live load of ______________________ pounds
per square foot in addition to all loads to which an underground tank is normally subjected. - CORRECT
ANSWER✅✅150
True or False: Walls, bottoms, and lids of poured-in-place septic tanks should have a minimum thickness
of four inches (4"). - CORRECT ANSWER✅✅True
Tank lids shall be constructed in ______________________ pieces and shall have securable, removable
access openings located so that the inlet and outlet tees can be ________________________________.
- CORRECT ANSWER✅✅one or two,
readily accessed.
Access opening shall have a minimum of _________________ and maximum of ___________________
free space. - CORRECT ANSWER✅✅Minimum: 15"
Maximum: 24"
Tanks with more than 12 inches of cover must extend access openings to within ______ inches of the
ground surface. - CORRECT ANSWER✅✅12
All tanks shall be equipped with ________________________________ rated or equivalent tees at the
inlet and outlet ends of the tank. - CORRECT ANSWER✅✅Four inch (4") PVC, ASTM 3034
Tees shall be constructed so they extend into the liquid a minimum of ____________________ and a
maximum of __________________ of the liquid depth of the tank. - CORRECT ANSWER✅✅Min: 25%
Max: 50%
The invert of the outlet tee shall be located _______________ inches below the invert of the inlet tee. -
CORRECT ANSWER✅✅two inches
__________________ tees shall be equipped with an approved effluent filter. - CORRECT
ANSWER✅✅Outlet
