2026 South Carolina Septic Tank Installer License
Exam | Practice Questions, Answers & Rationales
Fast-track your South Carolina environmental certification with this premium study
bundle containing practice questions for the DHEC Septic Tank Installer License Exam.
Features comprehensive multiple-choice questions, verified answers, and detailed
regulations-based rationales covering soil classification, trench dimensions, setbacks,
and system configurations.
Section 1: Licensing, Regulation & Permitting (Questions 1–10)
1. What is the primary state agency responsible for enforcing Regulation 61-56
and licensing septic tank contractors in South Carolina?
A. South Carolina Department of Transportation (SCDOT)
B. South Carolina Department of Labor, Licensing and Regulation (LLR)
C. South Carolina Department of Environmental Services (SCDES)
D. Environmental Protection Agency (EPA)
Answer: C. South Carolina Department of Environmental Services (SCDES)
Rationale: As of July 1, 2024, the former SCDHEC was reorganized, and the environmental
permitting and enforcement functions (including Regulation 61-56) were transferred to the
newly established SCDES.
2. According to Regulation 61-56, a construction permit for a septic system is
generally valid for how long from the date of issuance?
A. 1 Year
B. 3 Years
C. 5 Years
D. 10 Years
Answer: B. 3 Years
Rationale: Permits typically expire after 3 years if construction has not commenced or if no
substantial progress has been made. This ensures that site conditions (like water table
levels) are re-evaluated.
,3. Who is legally responsible for obtaining the construction permit before
installing a septic system in South Carolina?
A. The property owner
B. The general contractor building the house
C. The licensed septic tank installer
D. The real estate agent
Answer: C. The licensed septic tank installer
Rationale: A licensed installer must pull the permit. The regulation explicitly requires the
licensed professional to ensure the permit is issued or applied for before starting work.
4. What is the minimum score required to pass the South Carolina septic system
installer licensing examination?
A. 70%
B. 75%
C. 80%
D. 100%
Answer: C. 80%
Rationale: Candidates must achieve a score of 80% or better to pass the licensing exam.
This minimum score applies to both Tier 1/Tier 2 and Tier 3 applicants.
5. A Tier 1 Installer license allows you to perform which of the following tasks?
A. Installation of pressurized sewage systems
B. Installation of all gravity-fed residential onsite wastewater systems
C. Major repairs to existing failing drainfields
D. Soil classification without supervision
Answer: B. Installation of all gravity-fed residential onsite wastewater systems
Rationale: Tier 1 is the entry-level license for new gravity-fed systems. Repairs require Tier
2, and pressurized/commercial systems require Tier 3.
6. South Carolina Act No. 37 of 2015 details the installation of which type of
systems?
A. Pressurized commercial systems
B. Passive soil-based onsite disposal systems
,C. Standard 610 specialized systems
D. Mounded systems with sand fill
Answer: B. Passive soil-based onsite disposal systems
Rationale: Act No. 37 of 2015 details the installation of passive soil-based onsite disposal
systems, which consist of non-gravel, non-mechanical soil absorption trenches using
approved manufactured products such as Infiltrator and EZ Flow.
7. Only licensed septic system installers certified by whom can utilize the soil
absorption area reduction?
A. The local county zoning board
B. The trench product manufacturer
C. The EPA
D. The state legislature
Answer: B. The trench product manufacturer
Rationale: Only licensed septic system installers certified by the trench product
manufacturer can utilize the soil absorption area reduction. These systems must be
installed per the manufacturer requirements.
8. If you fail the installer licensing exam on your first attempt, how long must you
wait before you can retake it?
A. 7 days
B. 14 days
C. 30 days
D. 60 days
Answer: C. 30 days
Rationale: If you do not pass the test, you can retake it in 30 days. If you fail a second
time, you can wait 60 days and retake the exam a third time.
9. What is the penalty amount assessed for license fees sixty (60) days past due?
A. $10.00
B. $20.00
C. $30.00
D. $50.00
, Answer: C. $30.00
Rationale: A penalty of thirty dollars ($30.00) shall be assessed for license fees sixty (60)
days past due.
10. At what point does a license officially expire due to non-payment?
A. 30 calendar days past due
B. 60 calendar days past due
C. 90 calendar days past due
D. 120 calendar days past due
Answer: C. 90 calendar days past due
Rationale: Expiration of a license shall occur when the license fee is ninety (90) calendar
days past due. No person with an expired license may be engaged in the business of
constructing and repairing onsite wastewater systems.
Section 2: Site Evaluation, Soil & Setbacks (Questions 11–20)
11. What is the minimum vertical separation between the deepest point of effluent
application and the zone of saturation when peak sewage flow does NOT exceed
1,500 gallons per day?
A. 3 inches
B. 6 inches
C. 12 inches
D. 18 inches
Answer: B. 6 inches
Rationale: Where the estimated peak sewage flow will not exceed 1,500 gpd, the minimum
vertical separation between the deepest point of effluent application and the zone of
saturation shall be at least six (6) inches.
12. What is the depth to the zone of saturation required when peak sewage flow
exceeds 1,500 gallons per day?
A. 12 inches below the naturally occurring soil surface
B. 24 inches below the naturally occurring soil surface
C. 36 inches below the naturally occurring soil surface
D. 48 inches below the naturally occurring soil surface
Exam | Practice Questions, Answers & Rationales
Fast-track your South Carolina environmental certification with this premium study
bundle containing practice questions for the DHEC Septic Tank Installer License Exam.
Features comprehensive multiple-choice questions, verified answers, and detailed
regulations-based rationales covering soil classification, trench dimensions, setbacks,
and system configurations.
Section 1: Licensing, Regulation & Permitting (Questions 1–10)
1. What is the primary state agency responsible for enforcing Regulation 61-56
and licensing septic tank contractors in South Carolina?
A. South Carolina Department of Transportation (SCDOT)
B. South Carolina Department of Labor, Licensing and Regulation (LLR)
C. South Carolina Department of Environmental Services (SCDES)
D. Environmental Protection Agency (EPA)
Answer: C. South Carolina Department of Environmental Services (SCDES)
Rationale: As of July 1, 2024, the former SCDHEC was reorganized, and the environmental
permitting and enforcement functions (including Regulation 61-56) were transferred to the
newly established SCDES.
2. According to Regulation 61-56, a construction permit for a septic system is
generally valid for how long from the date of issuance?
A. 1 Year
B. 3 Years
C. 5 Years
D. 10 Years
Answer: B. 3 Years
Rationale: Permits typically expire after 3 years if construction has not commenced or if no
substantial progress has been made. This ensures that site conditions (like water table
levels) are re-evaluated.
,3. Who is legally responsible for obtaining the construction permit before
installing a septic system in South Carolina?
A. The property owner
B. The general contractor building the house
C. The licensed septic tank installer
D. The real estate agent
Answer: C. The licensed septic tank installer
Rationale: A licensed installer must pull the permit. The regulation explicitly requires the
licensed professional to ensure the permit is issued or applied for before starting work.
4. What is the minimum score required to pass the South Carolina septic system
installer licensing examination?
A. 70%
B. 75%
C. 80%
D. 100%
Answer: C. 80%
Rationale: Candidates must achieve a score of 80% or better to pass the licensing exam.
This minimum score applies to both Tier 1/Tier 2 and Tier 3 applicants.
5. A Tier 1 Installer license allows you to perform which of the following tasks?
A. Installation of pressurized sewage systems
B. Installation of all gravity-fed residential onsite wastewater systems
C. Major repairs to existing failing drainfields
D. Soil classification without supervision
Answer: B. Installation of all gravity-fed residential onsite wastewater systems
Rationale: Tier 1 is the entry-level license for new gravity-fed systems. Repairs require Tier
2, and pressurized/commercial systems require Tier 3.
6. South Carolina Act No. 37 of 2015 details the installation of which type of
systems?
A. Pressurized commercial systems
B. Passive soil-based onsite disposal systems
,C. Standard 610 specialized systems
D. Mounded systems with sand fill
Answer: B. Passive soil-based onsite disposal systems
Rationale: Act No. 37 of 2015 details the installation of passive soil-based onsite disposal
systems, which consist of non-gravel, non-mechanical soil absorption trenches using
approved manufactured products such as Infiltrator and EZ Flow.
7. Only licensed septic system installers certified by whom can utilize the soil
absorption area reduction?
A. The local county zoning board
B. The trench product manufacturer
C. The EPA
D. The state legislature
Answer: B. The trench product manufacturer
Rationale: Only licensed septic system installers certified by the trench product
manufacturer can utilize the soil absorption area reduction. These systems must be
installed per the manufacturer requirements.
8. If you fail the installer licensing exam on your first attempt, how long must you
wait before you can retake it?
A. 7 days
B. 14 days
C. 30 days
D. 60 days
Answer: C. 30 days
Rationale: If you do not pass the test, you can retake it in 30 days. If you fail a second
time, you can wait 60 days and retake the exam a third time.
9. What is the penalty amount assessed for license fees sixty (60) days past due?
A. $10.00
B. $20.00
C. $30.00
D. $50.00
, Answer: C. $30.00
Rationale: A penalty of thirty dollars ($30.00) shall be assessed for license fees sixty (60)
days past due.
10. At what point does a license officially expire due to non-payment?
A. 30 calendar days past due
B. 60 calendar days past due
C. 90 calendar days past due
D. 120 calendar days past due
Answer: C. 90 calendar days past due
Rationale: Expiration of a license shall occur when the license fee is ninety (90) calendar
days past due. No person with an expired license may be engaged in the business of
constructing and repairing onsite wastewater systems.
Section 2: Site Evaluation, Soil & Setbacks (Questions 11–20)
11. What is the minimum vertical separation between the deepest point of effluent
application and the zone of saturation when peak sewage flow does NOT exceed
1,500 gallons per day?
A. 3 inches
B. 6 inches
C. 12 inches
D. 18 inches
Answer: B. 6 inches
Rationale: Where the estimated peak sewage flow will not exceed 1,500 gpd, the minimum
vertical separation between the deepest point of effluent application and the zone of
saturation shall be at least six (6) inches.
12. What is the depth to the zone of saturation required when peak sewage flow
exceeds 1,500 gallons per day?
A. 12 inches below the naturally occurring soil surface
B. 24 inches below the naturally occurring soil surface
C. 36 inches below the naturally occurring soil surface
D. 48 inches below the naturally occurring soil surface
