South Carolina Septic Tank Contractor
Licensing Exam 2025/2026 – actual Exam
Format Questions & Answers with
Rationales | 100% Verified | Graded A+
Q1. What is the minimum license classification required to install septic tank systems in South
Carolina? Group III Septic Tank Contractor (PC-III). Rationale: Required for conventional
and alternative systems.
Q2. How many years of experience are required for the Septic Tank Contractor license in SC? 2
years full-time experience. Rationale: Must be under licensed contractor or equivalent.
Q3. What is the passing score for the SC Septic Tank Contractor exam? 70%. Rationale: PSI
exam; 100 questions, 4 hours.
Q4. How often must a SC Septic Tank Contractor license be renewed? Annually by June 30.
Rationale: $100 fee + 4 CE hours required.
Q5. What is the minimum lot size for conventional septic system in SC? 0.5 acre (21,780 sq ft).
Rationale: Smaller lots possible with engineered systems.
Q6. What is the minimum separation distance from septic tank to property line? 5 feet.
Rationale: Standard setback requirement.
Q7. Minimum separation from drainfield to property line? 10 feet. Rationale: Protects
neighboring properties.
, Q8. Minimum separation from septic tank to water supply well? 50 feet. Rationale: Drainfield
requires 100 feet.
Q9. What is the required soil absorption rate for conventional system? ≤120 minutes per inch.
Rationale: Slower soils require alternative systems.
Q10. What is the minimum effective soil depth to seasonal high water table? 24 inches.
Rationale: Ensures proper treatment.
Q11. What is the minimum tank size for 3-bedroom home? 1,000 gallons. Rationale: Based on
150 gal/bedroom minimum.
Q12. What material is required for septic tank baffles? Sanitary tee or equivalent. Rationale:
Inlet and outlet baffles prevent solids escape.
Q13. How often must septic tanks be pumped? Every 3–5 years. Rationale: Depends on
household size and usage.
Q14. What is the maximum slope for drainfield laterals? 4 inches per 100 feet. Rationale:
Ensures even distribution.
Q15. What is the minimum gravel depth under drain lines? 6 inches. Rationale: 2 inches above
pipe also required.
Q16. What is the required cover over drainfield? 12 inches minimum. Rationale: Protects lines
and promotes evapotranspiration.
Licensing Exam 2025/2026 – actual Exam
Format Questions & Answers with
Rationales | 100% Verified | Graded A+
Q1. What is the minimum license classification required to install septic tank systems in South
Carolina? Group III Septic Tank Contractor (PC-III). Rationale: Required for conventional
and alternative systems.
Q2. How many years of experience are required for the Septic Tank Contractor license in SC? 2
years full-time experience. Rationale: Must be under licensed contractor or equivalent.
Q3. What is the passing score for the SC Septic Tank Contractor exam? 70%. Rationale: PSI
exam; 100 questions, 4 hours.
Q4. How often must a SC Septic Tank Contractor license be renewed? Annually by June 30.
Rationale: $100 fee + 4 CE hours required.
Q5. What is the minimum lot size for conventional septic system in SC? 0.5 acre (21,780 sq ft).
Rationale: Smaller lots possible with engineered systems.
Q6. What is the minimum separation distance from septic tank to property line? 5 feet.
Rationale: Standard setback requirement.
Q7. Minimum separation from drainfield to property line? 10 feet. Rationale: Protects
neighboring properties.
, Q8. Minimum separation from septic tank to water supply well? 50 feet. Rationale: Drainfield
requires 100 feet.
Q9. What is the required soil absorption rate for conventional system? ≤120 minutes per inch.
Rationale: Slower soils require alternative systems.
Q10. What is the minimum effective soil depth to seasonal high water table? 24 inches.
Rationale: Ensures proper treatment.
Q11. What is the minimum tank size for 3-bedroom home? 1,000 gallons. Rationale: Based on
150 gal/bedroom minimum.
Q12. What material is required for septic tank baffles? Sanitary tee or equivalent. Rationale:
Inlet and outlet baffles prevent solids escape.
Q13. How often must septic tanks be pumped? Every 3–5 years. Rationale: Depends on
household size and usage.
Q14. What is the maximum slope for drainfield laterals? 4 inches per 100 feet. Rationale:
Ensures even distribution.
Q15. What is the minimum gravel depth under drain lines? 6 inches. Rationale: 2 inches above
pipe also required.
Q16. What is the required cover over drainfield? 12 inches minimum. Rationale: Protects lines
and promotes evapotranspiration.
