South Carolina DHEC Onsite Wastewater
Contractor Permit (Latest Update )
Questions & Answers with Rationales| 100% Correct
| Grade
What is required before installing an onsite wastewater system in SC?
Answer: Permit to Construct
Rationale: A Permit to Construct ensures compliance with SCDHEC
regulations before installation.
2. Which factor must a system design consider?
Answer: Soil percolation rate
Rationale: Soil suitability affects system performance and environmental
safety.
3. Which type of system requires a mound or raised bed design?
Answer: Shallow or poor-draining soil
Rationale: Mounds elevate the drain field above unsuitable soil layers.
4. What is the minimum distance a septic tank must be from a water well?
Answer: 50 feet
Rationale: Protects groundwater from contamination.
5. Which material is commonly used for septic tanks?
Answer: Concrete
Rationale: Concrete is durable, watertight, and resists soil pressure.
6. Who is responsible for proper installation of the system?
Answer: Licensed contractor
Rationale: Contractors are trained and certified to follow regulations.
, 7. What is the purpose of a distribution box?
Answer: Distribute effluent evenly to drain field
Rationale: Ensures uniform flow and prevents system failure.
8. When is soil testing required?
Answer: Before system design
Rationale: Determines system type and drain field suitability.
9. Which component of the system stores solids?
Answer: Septic tank
Rationale: Settles solids and allows effluent to flow to the drain field.
10.Which installation method requires compaction around the tank?
Answer: Concrete tank placement
Rationale: Prevents settling and damage.
11.How often should a septic tank be pumped?
Answer: Every 3–5 years
Rationale: Prevents solids from clogging the drain field.
12.What is the first sign of a failing drain field?
Answer: Slow drains or pooling
Rationale: Indicates effluent is not properly absorbed.
13.Which maintenance task prevents solids from entering the drain field?
Answer: Regular septic tank pumping
Rationale: Reduces solids buildup that can clog soil absorption.
14.Who can perform inspections of a system?
Answer: Licensed contractor or SCDHEC inspector
Rationale: Ensures inspections follow official guidelines.
15.Which activity is prohibited to protect the drain field?
Contractor Permit (Latest Update )
Questions & Answers with Rationales| 100% Correct
| Grade
What is required before installing an onsite wastewater system in SC?
Answer: Permit to Construct
Rationale: A Permit to Construct ensures compliance with SCDHEC
regulations before installation.
2. Which factor must a system design consider?
Answer: Soil percolation rate
Rationale: Soil suitability affects system performance and environmental
safety.
3. Which type of system requires a mound or raised bed design?
Answer: Shallow or poor-draining soil
Rationale: Mounds elevate the drain field above unsuitable soil layers.
4. What is the minimum distance a septic tank must be from a water well?
Answer: 50 feet
Rationale: Protects groundwater from contamination.
5. Which material is commonly used for septic tanks?
Answer: Concrete
Rationale: Concrete is durable, watertight, and resists soil pressure.
6. Who is responsible for proper installation of the system?
Answer: Licensed contractor
Rationale: Contractors are trained and certified to follow regulations.
, 7. What is the purpose of a distribution box?
Answer: Distribute effluent evenly to drain field
Rationale: Ensures uniform flow and prevents system failure.
8. When is soil testing required?
Answer: Before system design
Rationale: Determines system type and drain field suitability.
9. Which component of the system stores solids?
Answer: Septic tank
Rationale: Settles solids and allows effluent to flow to the drain field.
10.Which installation method requires compaction around the tank?
Answer: Concrete tank placement
Rationale: Prevents settling and damage.
11.How often should a septic tank be pumped?
Answer: Every 3–5 years
Rationale: Prevents solids from clogging the drain field.
12.What is the first sign of a failing drain field?
Answer: Slow drains or pooling
Rationale: Indicates effluent is not properly absorbed.
13.Which maintenance task prevents solids from entering the drain field?
Answer: Regular septic tank pumping
Rationale: Reduces solids buildup that can clog soil absorption.
14.Who can perform inspections of a system?
Answer: Licensed contractor or SCDHEC inspector
Rationale: Ensures inspections follow official guidelines.
15.Which activity is prohibited to protect the drain field?
