South Carolina Septic Tank Contractor Practice Exam
200 Questions | SCDES Licensing Test | R.61-56 | SC
Onsite Wastewater Exam Prep | Updated for 2026 |
Instant Pdf Download
Total Questions: 200 | Passing Score (Official Exam): 80% |
OVERVEIW
This examination is designed specifically for candidates preparing for the South Carolina Department of
Environmental Services (SCDES) Septic Tank Contractor Licensing Examination (formerly DHEC) .
The exam evaluates knowledge and competency required for professionals installing, repairing, and
maintaining onsite wastewater systems throughout South Carolina.
The official SCDES Septic Tank Contractor Exam is governed by Regulation 61-56 (Onsite Wastewater
Systems) and covers the following core domains:
Licensing, Regulations & Permitting – SCDES authority, permit requirements, license tiers (Tier 1, 2, 3),
application process, renewal requirements, and penalties for violations
Site Evaluation & Soil Science – soil texture, percolation tests, mottling, redox features, restrictive
horizons, seasonal high water table, soil color determination (Munsell system)
System Design & Sizing – septic tank sizing (minimum 1,000 gallons for 3-bedroom homes), drainfield
trench length, absorption area calculations, distribution boxes
Installation Practices – tank bedding, pipe slopes (1-2 inches per 100 feet), backfill procedures,
inspection requirements before covering, riser installation
Maintenance & Troubleshooting – pumping frequency (every 3-5 years), signs of system failure, bio-mat
buildup, short cycling, surfacing effluent
Alternative Systems & Advanced Technology – mound systems, fill systems, elevated infiltration areas,
aerobic treatment units, drip irrigation systems
Safety & OSHA Compliance – confined space entry procedures, toxic gases (hydrogen sulfide, methane),
PPE requirements, excavation safety
SCDES Rules & South Carolina Regulations – Regulation 61-56 requirements, separation distances
(wells, property lines, surface water), permitting timelines (12-month validity), as-built documentation
Format: Each question includes four answer choices (A, B, C, D). The correct answer is clearly marked
in bold italics. Each question is followed by a bolded "Explanation" label and an italicized
explanation that provides the reasoning, code reference, or industry standard supporting the correct an
,Section 1: Licensing, Regulations & Permitting (Questions 1–30)
1. Which agency regulates onsite wastewater systems in South
Carolina?
a) South Carolina Department of Labor, Licensing and Regulation
b) U.S. Environmental Protection Agency (EPA)
c) South Carolina Department of Environmental Services (SCDES)
d) South Carolina Department of Natural Resources
Explanation *SCDES (formerly DHEC) oversees permitting, inspection,
and maintenance of all septic systems statewide under Regulation 61-
56.*
2. A septic contractor in South Carolina must hold which type of
license to install systems?
a) Home Inspector License
b) Residential Builder License
c) Septic Tank Contractor License issued by SCDES
d) Mechanical Contractor License
Explanation SCDES issues septic installer licenses specific to onsite
wastewater work; separate licenses exist for Tier 1, Tier 2, and Tier 3
installers.
3. Which of the following requires a new SCDES septic permit?
a) Replacing a broken riser
,b) Cleaning an existing tank
c) Relocating a tank or drainfield
d) Pumping the tank
Explanation Any relocation or major modification of system
components requires a new construction permit from SCDES.
4. How long is a septic system construction permit valid in South
Carolina?
a) 6 months
b) 9 months
c) 12 months
d) 24 months
Explanation SCDES permits are valid for 12 months from the issue date.
If construction is not completed within that time, the permit expires.
5. When must the septic system be inspected by SCDES?
a) After backfill
b) After system use begins
c) Before the system is covered
d) Only after final grading
Explanation SCDES must inspect the system prior to backfill to verify
compliance with approved plans and proper installation.
, 6. What is the minimum lot size required for a septic system in South
Carolina?
a) 1/4 acre
b) 1/2 acre
c) 3/4 acre
d) No statewide minimum; determined by site evaluation
Explanation *SCDHEC Regulation 61-56 does not specify a minimum lot
size; suitability is determined by soil evaluation, percolation tests, and
required setbacks.*
7. What is the primary purpose of a septic tank?
a) To treat wastewater with chemicals
b) To aerate the effluent
c) To separate solids from liquids and provide partial treatment
d) To disinfect the wastewater
Explanation The septic tank allows solids to settle as sludge while fats
and oils float as scum, providing primary treatment before effluent
enters the drainfield.
8. A septic tank must be watertight primarily to:
a) Reduce construction costs
b) Allow groundwater infiltration
c) Prevent roots from entering
d) Prevent untreated sewage from leaking into groundwater
200 Questions | SCDES Licensing Test | R.61-56 | SC
Onsite Wastewater Exam Prep | Updated for 2026 |
Instant Pdf Download
Total Questions: 200 | Passing Score (Official Exam): 80% |
OVERVEIW
This examination is designed specifically for candidates preparing for the South Carolina Department of
Environmental Services (SCDES) Septic Tank Contractor Licensing Examination (formerly DHEC) .
The exam evaluates knowledge and competency required for professionals installing, repairing, and
maintaining onsite wastewater systems throughout South Carolina.
The official SCDES Septic Tank Contractor Exam is governed by Regulation 61-56 (Onsite Wastewater
Systems) and covers the following core domains:
Licensing, Regulations & Permitting – SCDES authority, permit requirements, license tiers (Tier 1, 2, 3),
application process, renewal requirements, and penalties for violations
Site Evaluation & Soil Science – soil texture, percolation tests, mottling, redox features, restrictive
horizons, seasonal high water table, soil color determination (Munsell system)
System Design & Sizing – septic tank sizing (minimum 1,000 gallons for 3-bedroom homes), drainfield
trench length, absorption area calculations, distribution boxes
Installation Practices – tank bedding, pipe slopes (1-2 inches per 100 feet), backfill procedures,
inspection requirements before covering, riser installation
Maintenance & Troubleshooting – pumping frequency (every 3-5 years), signs of system failure, bio-mat
buildup, short cycling, surfacing effluent
Alternative Systems & Advanced Technology – mound systems, fill systems, elevated infiltration areas,
aerobic treatment units, drip irrigation systems
Safety & OSHA Compliance – confined space entry procedures, toxic gases (hydrogen sulfide, methane),
PPE requirements, excavation safety
SCDES Rules & South Carolina Regulations – Regulation 61-56 requirements, separation distances
(wells, property lines, surface water), permitting timelines (12-month validity), as-built documentation
Format: Each question includes four answer choices (A, B, C, D). The correct answer is clearly marked
in bold italics. Each question is followed by a bolded "Explanation" label and an italicized
explanation that provides the reasoning, code reference, or industry standard supporting the correct an
,Section 1: Licensing, Regulations & Permitting (Questions 1–30)
1. Which agency regulates onsite wastewater systems in South
Carolina?
a) South Carolina Department of Labor, Licensing and Regulation
b) U.S. Environmental Protection Agency (EPA)
c) South Carolina Department of Environmental Services (SCDES)
d) South Carolina Department of Natural Resources
Explanation *SCDES (formerly DHEC) oversees permitting, inspection,
and maintenance of all septic systems statewide under Regulation 61-
56.*
2. A septic contractor in South Carolina must hold which type of
license to install systems?
a) Home Inspector License
b) Residential Builder License
c) Septic Tank Contractor License issued by SCDES
d) Mechanical Contractor License
Explanation SCDES issues septic installer licenses specific to onsite
wastewater work; separate licenses exist for Tier 1, Tier 2, and Tier 3
installers.
3. Which of the following requires a new SCDES septic permit?
a) Replacing a broken riser
,b) Cleaning an existing tank
c) Relocating a tank or drainfield
d) Pumping the tank
Explanation Any relocation or major modification of system
components requires a new construction permit from SCDES.
4. How long is a septic system construction permit valid in South
Carolina?
a) 6 months
b) 9 months
c) 12 months
d) 24 months
Explanation SCDES permits are valid for 12 months from the issue date.
If construction is not completed within that time, the permit expires.
5. When must the septic system be inspected by SCDES?
a) After backfill
b) After system use begins
c) Before the system is covered
d) Only after final grading
Explanation SCDES must inspect the system prior to backfill to verify
compliance with approved plans and proper installation.
, 6. What is the minimum lot size required for a septic system in South
Carolina?
a) 1/4 acre
b) 1/2 acre
c) 3/4 acre
d) No statewide minimum; determined by site evaluation
Explanation *SCDHEC Regulation 61-56 does not specify a minimum lot
size; suitability is determined by soil evaluation, percolation tests, and
required setbacks.*
7. What is the primary purpose of a septic tank?
a) To treat wastewater with chemicals
b) To aerate the effluent
c) To separate solids from liquids and provide partial treatment
d) To disinfect the wastewater
Explanation The septic tank allows solids to settle as sludge while fats
and oils float as scum, providing primary treatment before effluent
enters the drainfield.
8. A septic tank must be watertight primarily to:
a) Reduce construction costs
b) Allow groundwater infiltration
c) Prevent roots from entering
d) Prevent untreated sewage from leaking into groundwater
