CT Septic License Exam Questions and
answers with verified Answers
(Latest Update 2026) UPDATE
• What are the capacities for each side of a septic tank? -✓✓2/3 inlet side, 1/3
outlet side
• How many inches lower should the outlet be from the inlet in a septic tank? -
✓✓3"
• What information must be present on the outlet side of a septic tank? -✓✓- Name
of manufacturer
- Date manufactured
- Size of tank in gallons
- External load limit
- Warning placard
• How many additional gallons per bedroom are required for each bedroom beyond
3? -✓✓125 gallons
• How many additional gallons per bedroom are required for each bedroom beyond
4? -✓✓225 gallons
• How far below finished grade can clean out and baffle inspection manholes be? -
✓✓No deeper than 12"
• Tank riser covers shall be at least _________ lbs, or_______________________,
or _______________________________ -✓✓59 lbs, tank covers shall remain on
tank clean outs, a secondary safety device shall be provided
• What are the 3 main functions of a septic tank? -✓✓1. Removes most of the
settleable solids
2. Provides and effluent of relatively uniform physical, chemical and biological
characteristics
3. Provides some reduction in pollution levels in the effluent
, • Where should perc tests be conducted? -✓✓In primary and reserve septic areas
• How many inches maximum should a perc hole be? -✓✓12"
• How many inches of water shall be used for a perc test presoak? -✓✓12"
• How many inches of water shall be used for a perc test? -✓✓12"
• How many consecutive readings shall be taken for a perc test -✓✓3
• Perc test readings are measured to the nearest ______" -✓✓1/8"
• What is the perc rate calculation? -✓✓Time/Reading in inches
• No leaching system shall be constructed in areas where: -✓✓- High groundwater
- Surface flooding
- Ledge rock
• Leaching system shall be a minimum of 18" above: -✓✓- Groundwater
- Mottling
- Hardpan
• Leaching system shall be ____' above ledge or fractured rock -✓✓4'
• Leaching system shall be ____" above decomposing ledge (rock) -✓✓24"
• Where underlying natural soil has a perc rate faster than one minute per inch, the
bottom shall not be less than ____' above ledge rock -✓✓8'
• Where underlying natural soil has a perc rate faster than one minute per inch, the
bottom shall not be less than ____" above maximum groundwater -✓✓24"
• In a gravity system leaching field, what is the maximum length from either side
of a d-box? -✓✓75'
answers with verified Answers
(Latest Update 2026) UPDATE
• What are the capacities for each side of a septic tank? -✓✓2/3 inlet side, 1/3
outlet side
• How many inches lower should the outlet be from the inlet in a septic tank? -
✓✓3"
• What information must be present on the outlet side of a septic tank? -✓✓- Name
of manufacturer
- Date manufactured
- Size of tank in gallons
- External load limit
- Warning placard
• How many additional gallons per bedroom are required for each bedroom beyond
3? -✓✓125 gallons
• How many additional gallons per bedroom are required for each bedroom beyond
4? -✓✓225 gallons
• How far below finished grade can clean out and baffle inspection manholes be? -
✓✓No deeper than 12"
• Tank riser covers shall be at least _________ lbs, or_______________________,
or _______________________________ -✓✓59 lbs, tank covers shall remain on
tank clean outs, a secondary safety device shall be provided
• What are the 3 main functions of a septic tank? -✓✓1. Removes most of the
settleable solids
2. Provides and effluent of relatively uniform physical, chemical and biological
characteristics
3. Provides some reduction in pollution levels in the effluent
, • Where should perc tests be conducted? -✓✓In primary and reserve septic areas
• How many inches maximum should a perc hole be? -✓✓12"
• How many inches of water shall be used for a perc test presoak? -✓✓12"
• How many inches of water shall be used for a perc test? -✓✓12"
• How many consecutive readings shall be taken for a perc test -✓✓3
• Perc test readings are measured to the nearest ______" -✓✓1/8"
• What is the perc rate calculation? -✓✓Time/Reading in inches
• No leaching system shall be constructed in areas where: -✓✓- High groundwater
- Surface flooding
- Ledge rock
• Leaching system shall be a minimum of 18" above: -✓✓- Groundwater
- Mottling
- Hardpan
• Leaching system shall be ____' above ledge or fractured rock -✓✓4'
• Leaching system shall be ____" above decomposing ledge (rock) -✓✓24"
• Where underlying natural soil has a perc rate faster than one minute per inch, the
bottom shall not be less than ____' above ledge rock -✓✓8'
• Where underlying natural soil has a perc rate faster than one minute per inch, the
bottom shall not be less than ____" above maximum groundwater -✓✓24"
• In a gravity system leaching field, what is the maximum length from either side
of a d-box? -✓✓75'
