New Hampshire Septic Installer Exam 2
System Installation & Construction: Questions and
Answers| Updated| Pass Guaranteed
1. What is the primary function of a septic tank?
A. Disinfect wastewater so it can be discharged to the surface
B. Remove all nitrogen and phosphorus from wastewater
C. Store effluent for later irrigation use
D. Separate and retain solids and scum while partially digesting them,
producing clarified effluent
Answer: D
Rationale: The tank provides settling, flotation of grease/scum, and partial
anaerobic digestion of solids. It does not disinfect or remove nutrients; the
soil disposal area provides the remaining treatment.
2. What is the purpose of the inlet baffle or inlet tee in a septic tank?
A. Direct incoming flow downward, reduce turbulence, and prevent
short-circuiting and scum disturbance
B. Increase the tank's liquid volume
C. Allow gases to pass directly to the disposal field
D. Filter effluent before it leaves the tank
Answer: A
Rationale: The inlet device dissipates the energy of incoming wastewater
so settled solids are not stirred up and flow does not travel straight to the
outlet.
NH Septic Installer Exam 2 - Page 1
,3. The outlet tee or effluent filter on a septic tank is designed to:
A. Admit air into the tank
B. Slow the flow of water into the tank
C. Keep scum and solids from leaving the tank and entering the
distribution system
D. Increase the amount of sludge produced
Answer: C
Rationale: The outlet device draws clarified effluent from the middle zone,
below the scum layer and above the sludge layer, protecting the disposal
area from clogging.
4. Before backfilling a newly set septic tank, the installer should:
A. Remove all bedding material under the tank
B. Cover the tank to hide it from inspection
C. Verify the tank is level, undamaged, properly bedded, and passes
any required watertightness check
D. Drill drain holes in the bottom of the tank
Answer: C
Rationale: Tanks must be inspected before being covered. Cracks,
improper leveling, or leaks are far easier to correct before backfill.
5. Why is a septic tank set on a firm, level, compacted bedding?
A. To prevent settling, tilting, and stress cracks that can damage the
tank and break pipe connections
B. To increase infiltration through the tank bottom
C. To allow the tank to drain into the soil
D. To raise the inlet above the outlet
Answer: A
Rationale: An uneven or soft base causes differential settlement, which
can crack the tank and shear inlet and outlet pipes.
NH Septic Installer Exam 2 - Page 2
,6. Why is it important that a septic tank be watertight?
A. To increase the digestion rate of solids
B. To make pumping unnecessary
C. To eliminate the need for a vent
D. To prevent exfiltration of sewage and infiltration of groundwater
Answer: D
Rationale: Leaks out contaminate soil and groundwater; leaks in add
hydraulic load that can overload the disposal area and reduce treatment.
7. What is the purpose of access risers on a septic tank?
A. Increase the tank's capacity
B. Bring access openings to or near finished grade for inspection and
maintenance without excavation
C. Provide a second inlet for greywater
D. Allow surface water to enter the tank
Answer: B
Rationale: Risers make pumping and inspection easy, which promotes
regular maintenance. Lids must be watertight and secured against
unauthorized access.
8. A tank is being installed where the seasonal high water table is
above the tank bottom. What is the main concern?
A. Excess sludge production
B. Buoyancy, because an empty tank can float
C. Failure of the inlet baffle
D. Low flow into the tank
Answer: B
Rationale: High groundwater can lift an empty tank. Remedies include
proper tank design and anti-flotation measures, dewatering during
installation, and filling the tank with water as soon as it is set.
NH Septic Installer Exam 2 - Page 3
, 9. Which statement about tank inlet and outlet elevations is correct?
A. The outlet must be higher than the inlet
B. Both must be at exactly the same elevation
C. Elevations do not matter in a watertight tank
D. The inlet invert must be higher than the outlet invert so wastewater
flows through by gravity
Answer: D
Rationale: The slight drop across the tank, typically a few inches, keeps
flow moving and helps prevent backup into the building sewer.
10. Tanks that will be subject to vehicle traffic must be:
A. Designed and rated for the anticipated loads, or protected with an
engineered design
B. Any standard residential tank
C. Installed without risers
D. Set at least 6 inches above grade
Answer: A
Rationale: Standard tanks may collapse under traffic loads. Tank rating,
cover depth, and lid design must match the loading.
11. Why do two compartments, or two tanks in series, often improve
performance?
A. They double the amount of effluent produced
B. They eliminate the need for a disposal area
C. They increase solids retention and reduce the solids carried out in the
effluent
D. They allow the tank to be buried deeper
Answer: C
Rationale: The second compartment provides additional quiet settling and
acts as a final barrier for solids before the effluent leaves the tank.
NH Septic Installer Exam 2 - Page 4
System Installation & Construction: Questions and
Answers| Updated| Pass Guaranteed
1. What is the primary function of a septic tank?
A. Disinfect wastewater so it can be discharged to the surface
B. Remove all nitrogen and phosphorus from wastewater
C. Store effluent for later irrigation use
D. Separate and retain solids and scum while partially digesting them,
producing clarified effluent
Answer: D
Rationale: The tank provides settling, flotation of grease/scum, and partial
anaerobic digestion of solids. It does not disinfect or remove nutrients; the
soil disposal area provides the remaining treatment.
2. What is the purpose of the inlet baffle or inlet tee in a septic tank?
A. Direct incoming flow downward, reduce turbulence, and prevent
short-circuiting and scum disturbance
B. Increase the tank's liquid volume
C. Allow gases to pass directly to the disposal field
D. Filter effluent before it leaves the tank
Answer: A
Rationale: The inlet device dissipates the energy of incoming wastewater
so settled solids are not stirred up and flow does not travel straight to the
outlet.
NH Septic Installer Exam 2 - Page 1
,3. The outlet tee or effluent filter on a septic tank is designed to:
A. Admit air into the tank
B. Slow the flow of water into the tank
C. Keep scum and solids from leaving the tank and entering the
distribution system
D. Increase the amount of sludge produced
Answer: C
Rationale: The outlet device draws clarified effluent from the middle zone,
below the scum layer and above the sludge layer, protecting the disposal
area from clogging.
4. Before backfilling a newly set septic tank, the installer should:
A. Remove all bedding material under the tank
B. Cover the tank to hide it from inspection
C. Verify the tank is level, undamaged, properly bedded, and passes
any required watertightness check
D. Drill drain holes in the bottom of the tank
Answer: C
Rationale: Tanks must be inspected before being covered. Cracks,
improper leveling, or leaks are far easier to correct before backfill.
5. Why is a septic tank set on a firm, level, compacted bedding?
A. To prevent settling, tilting, and stress cracks that can damage the
tank and break pipe connections
B. To increase infiltration through the tank bottom
C. To allow the tank to drain into the soil
D. To raise the inlet above the outlet
Answer: A
Rationale: An uneven or soft base causes differential settlement, which
can crack the tank and shear inlet and outlet pipes.
NH Septic Installer Exam 2 - Page 2
,6. Why is it important that a septic tank be watertight?
A. To increase the digestion rate of solids
B. To make pumping unnecessary
C. To eliminate the need for a vent
D. To prevent exfiltration of sewage and infiltration of groundwater
Answer: D
Rationale: Leaks out contaminate soil and groundwater; leaks in add
hydraulic load that can overload the disposal area and reduce treatment.
7. What is the purpose of access risers on a septic tank?
A. Increase the tank's capacity
B. Bring access openings to or near finished grade for inspection and
maintenance without excavation
C. Provide a second inlet for greywater
D. Allow surface water to enter the tank
Answer: B
Rationale: Risers make pumping and inspection easy, which promotes
regular maintenance. Lids must be watertight and secured against
unauthorized access.
8. A tank is being installed where the seasonal high water table is
above the tank bottom. What is the main concern?
A. Excess sludge production
B. Buoyancy, because an empty tank can float
C. Failure of the inlet baffle
D. Low flow into the tank
Answer: B
Rationale: High groundwater can lift an empty tank. Remedies include
proper tank design and anti-flotation measures, dewatering during
installation, and filling the tank with water as soon as it is set.
NH Septic Installer Exam 2 - Page 3
, 9. Which statement about tank inlet and outlet elevations is correct?
A. The outlet must be higher than the inlet
B. Both must be at exactly the same elevation
C. Elevations do not matter in a watertight tank
D. The inlet invert must be higher than the outlet invert so wastewater
flows through by gravity
Answer: D
Rationale: The slight drop across the tank, typically a few inches, keeps
flow moving and helps prevent backup into the building sewer.
10. Tanks that will be subject to vehicle traffic must be:
A. Designed and rated for the anticipated loads, or protected with an
engineered design
B. Any standard residential tank
C. Installed without risers
D. Set at least 6 inches above grade
Answer: A
Rationale: Standard tanks may collapse under traffic loads. Tank rating,
cover depth, and lid design must match the loading.
11. Why do two compartments, or two tanks in series, often improve
performance?
A. They double the amount of effluent produced
B. They eliminate the need for a disposal area
C. They increase solids retention and reduce the solids carried out in the
effluent
D. They allow the tank to be buried deeper
Answer: C
Rationale: The second compartment provides additional quiet settling and
acts as a final barrier for solids before the effluent leaves the tank.
NH Septic Installer Exam 2 - Page 4
