Texas OSSF Site Evaluator Exam Question and
correct answers (verified answers 100%) Q&A
2026/2027 INSTANT DOWNLOAD PDF
1. What is the primary purpose of a site evaluation for an OSSF?
A. Determine the property tax value
B. Determine whether the site can adequately support an OSSF
C. Select the plumbing fixtures
D. Determine the home's electrical load
Answer: B. Determine whether the site can adequately support an OSSF.
Rationale: A site evaluation identifies soil, groundwater, topographic, and other site
characteristics needed to determine appropriate wastewater treatment and dispersal.
2. Which soil characteristic is especially important when evaluating an OSSF site?
A. Soil color only
B. Soil texture and structure
C. Soil temperature only
D. Soil surface appearance only
Answer: B. Soil texture and structure.
Rationale: Texture and structure influence permeability, drainage, treatment, and the movement
of wastewater through the soil.
3. What does soil texture describe?
A. Soil depth only
B. Relative proportions of sand, silt, and clay
C. Soil slope
D. Soil temperature
Answer: B. Relative proportions of sand, silt, and clay.
Rationale: Soil texture is based on the relative amounts of sand, silt, and clay particles.
4. Why is groundwater important during an OSSF site evaluation?
A. It determines the home's water pressure
B. It can affect treatment and groundwater contamination risk
C. It determines the septic tank color
D. It controls electrical voltage
,Answer: B. It can affect treatment and groundwater contamination risk.
Rationale: High groundwater can limit soil treatment capacity and increase the risk of untreated
wastewater reaching groundwater.
5. What is a restrictive soil layer?
A. A layer that allows unlimited wastewater movement
B. A layer that restricts the movement of water or wastewater
C. A layer containing only topsoil
D. A layer used for landscaping
Answer: B. A layer that restricts the movement of water or wastewater.
Rationale: Restrictive layers can include dense materials, bedrock, or other horizons that impede
vertical or horizontal movement.
6. Which feature should be identified during a site evaluation?
A. Property's interior furniture
B. Surface water bodies
C. Home appliances
D. Vehicle mileage
Answer: B. Surface water bodies.
Rationale: Streams, ponds, lakes, and other surface waters can impose separation requirements
and environmental constraints.
7. What does soil structure refer to?
A. The arrangement of individual soil particles into aggregates
B. The percentage of sand only
C. The color of the soil
D. The depth of the septic tank
Answer: A. The arrangement of individual soil particles into aggregates.
Rationale: Soil structure describes how soil particles are grouped or arranged, affecting water
movement.
8. Why should slopes be evaluated during an OSSF site assessment?
A. Slope affects wastewater dispersal and system layout
B. Slope determines the home's roof color
C. Slope determines electrical frequency
D. Slope has no effect on an OSSF
, Answer: A. Slope affects wastewater dispersal and system layout.
Rationale: Excessive or irregular slopes can affect installation, drainage, erosion, and
wastewater distribution.
9. What is the purpose of identifying soil horizons?
A. To determine the home's age
B. To understand changes in soil properties with depth
C. To identify plumbing fixtures
D. To calculate electrical demand
Answer: B. To understand changes in soil properties with depth.
Rationale: Different horizons may have different textures, structures, colors, and restrictions that
influence system suitability.
10. Which professional activity is most directly associated with a site evaluator?
A. Evaluating soil and site conditions
B. Installing household wiring
C. Repairing vehicles
D. Painting buildings
Answer: A. Evaluating soil and site conditions.
Rationale: The site evaluator's role is to assess site characteristics relevant to OSSF design and
placement.
11. What is a soil profile?
A. A description of soil characteristics by depth
B. A property tax document
C. A plumbing diagram
D. A septic tank inspection receipt
Answer: A. A description of soil characteristics by depth.
Rationale: A soil profile documents the various soil horizons and their characteristics from the
surface downward.
12. Which soil generally has the smallest particle size?
A. Gravel
B. Sand
C. Silt
D. Clay
correct answers (verified answers 100%) Q&A
2026/2027 INSTANT DOWNLOAD PDF
1. What is the primary purpose of a site evaluation for an OSSF?
A. Determine the property tax value
B. Determine whether the site can adequately support an OSSF
C. Select the plumbing fixtures
D. Determine the home's electrical load
Answer: B. Determine whether the site can adequately support an OSSF.
Rationale: A site evaluation identifies soil, groundwater, topographic, and other site
characteristics needed to determine appropriate wastewater treatment and dispersal.
2. Which soil characteristic is especially important when evaluating an OSSF site?
A. Soil color only
B. Soil texture and structure
C. Soil temperature only
D. Soil surface appearance only
Answer: B. Soil texture and structure.
Rationale: Texture and structure influence permeability, drainage, treatment, and the movement
of wastewater through the soil.
3. What does soil texture describe?
A. Soil depth only
B. Relative proportions of sand, silt, and clay
C. Soil slope
D. Soil temperature
Answer: B. Relative proportions of sand, silt, and clay.
Rationale: Soil texture is based on the relative amounts of sand, silt, and clay particles.
4. Why is groundwater important during an OSSF site evaluation?
A. It determines the home's water pressure
B. It can affect treatment and groundwater contamination risk
C. It determines the septic tank color
D. It controls electrical voltage
,Answer: B. It can affect treatment and groundwater contamination risk.
Rationale: High groundwater can limit soil treatment capacity and increase the risk of untreated
wastewater reaching groundwater.
5. What is a restrictive soil layer?
A. A layer that allows unlimited wastewater movement
B. A layer that restricts the movement of water or wastewater
C. A layer containing only topsoil
D. A layer used for landscaping
Answer: B. A layer that restricts the movement of water or wastewater.
Rationale: Restrictive layers can include dense materials, bedrock, or other horizons that impede
vertical or horizontal movement.
6. Which feature should be identified during a site evaluation?
A. Property's interior furniture
B. Surface water bodies
C. Home appliances
D. Vehicle mileage
Answer: B. Surface water bodies.
Rationale: Streams, ponds, lakes, and other surface waters can impose separation requirements
and environmental constraints.
7. What does soil structure refer to?
A. The arrangement of individual soil particles into aggregates
B. The percentage of sand only
C. The color of the soil
D. The depth of the septic tank
Answer: A. The arrangement of individual soil particles into aggregates.
Rationale: Soil structure describes how soil particles are grouped or arranged, affecting water
movement.
8. Why should slopes be evaluated during an OSSF site assessment?
A. Slope affects wastewater dispersal and system layout
B. Slope determines the home's roof color
C. Slope determines electrical frequency
D. Slope has no effect on an OSSF
, Answer: A. Slope affects wastewater dispersal and system layout.
Rationale: Excessive or irregular slopes can affect installation, drainage, erosion, and
wastewater distribution.
9. What is the purpose of identifying soil horizons?
A. To determine the home's age
B. To understand changes in soil properties with depth
C. To identify plumbing fixtures
D. To calculate electrical demand
Answer: B. To understand changes in soil properties with depth.
Rationale: Different horizons may have different textures, structures, colors, and restrictions that
influence system suitability.
10. Which professional activity is most directly associated with a site evaluator?
A. Evaluating soil and site conditions
B. Installing household wiring
C. Repairing vehicles
D. Painting buildings
Answer: A. Evaluating soil and site conditions.
Rationale: The site evaluator's role is to assess site characteristics relevant to OSSF design and
placement.
11. What is a soil profile?
A. A description of soil characteristics by depth
B. A property tax document
C. A plumbing diagram
D. A septic tank inspection receipt
Answer: A. A description of soil characteristics by depth.
Rationale: A soil profile documents the various soil horizons and their characteristics from the
surface downward.
12. Which soil generally has the smallest particle size?
A. Gravel
B. Sand
C. Silt
D. Clay
