Texas OSSF Site Evaluator 2026/2027 | TCEQ Site
Evaluator License Exam Study Guide & Practice
Questions | Soil Analysis, Site Evaluation, Septic
Systems, Groundwater, Soil Classification & Texas
OSSF Regulations
Question 1: According to 30 TAC §285.30, who is authorized to perform
a complete site evaluation on a tract of land where an OSSF will be
installed?
A. A licensed installer or apprentice
B. A designated representative or maintenance provider
C. A site evaluator or professional engineer
D. A homeowner or registered sanitarian
CORRECT ANSWER: C. A site evaluator or professional engineer
Rationale: 30 TAC §285.30(a) explicitly requires that a complete site
evaluation be performed by either a site evaluator or a professional
engineer, and a report documenting the evaluation must be submitted with
the planning materials.
Question 2: When conducting a soil analysis for a site evaluation, how
many soil borings or backhoe pits must be drilled or excavated at
minimum?
A. One boring at the center of the proposed disposal area
B. Two borings at opposite ends of the proposed disposal area
C. Three borings evenly spaced across the site
D. Four borings at each corner of the property
CORRECT ANSWER: B. Two borings at opposite ends of the proposed
disposal area
Rationale: 30 TAC §285.30(b)(1) mandates that the site evaluator drill two
soil borings or excavate two backhoe pits at opposite ends of the proposed
disposal area to determine soil characteristics.
Question 3: To what depth must soil borings or backhoe pits be
excavated during a site evaluation?
A. Six inches below the proposed excavation
B. One foot below the proposed excavation
C. Two feet below the adopted excavation or to a restrictive horizon,
,whichever is less
D. Three feet below the adopted excavation regardless of soil conditions
CORRECT ANSWER: C. Two feet below the adopted excavation or to a
restrictive horizon, whichever is less
Rationale: 30 TAC §285.30(b)(1) specifies that borings or backhoe pits shall
be excavated to a depth of two feet below the adopted excavation of the
disposal area, or to a restrictive horizon, whichever is less.
Question 4: Which soil class includes sandy textured soils that contain
more than 30% gravel?
A. Soil Class Ia
B. Soil Class Ib
C. Soil Class II
D. Soil Class III
CORRECT ANSWER: A. Soil Class Ia
Rationale: According to 30 TAC §285.30(b)(1)(A)(i), Soil Class Ia includes
sandy textured soils containing more than 30% gravel.
Question 5: Soil Class Ib soils are defined as sand and loamy sand soils
containing what percentage of gravel?
A. More than 30%
B. Less than or equal to 30%
C. Between 10% and 50%
D. Exactly 0%
CORRECT ANSWER: B. Less than or equal to 30%
Rationale: 30 TAC §285.30(b)(1)(A)(ii) defines Soil Class Ib as sand and
loamy sand soils that contain less than or equal to 30% gravel.
Question 6: Which of the following soil textures is classified as Soil
Class II?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt loam and silty clay loam
D. Silty clay and clay
CORRECT ANSWER: B. Sandy loam and loam
,Rationale: Soil Class II includes sandy loam and loam soils as specified in
30 TAC §285.30(b)(1)(A)(iii).
Question 7: Soil Class III includes which of the following soil textures?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt, silt loam, silty clay loam, clay loam, sandy clay loam, and sandy
clay
D. Silty clay and clay
CORRECT ANSWER: C. Silt, silt loam, silty clay loam, clay loam, sandy
clay loam, and sandy clay
Rationale: 30 TAC §285.30(b)(1)(A)(iv) classifies silt, silt loam, silty clay
loam, clay loam, sandy clay loam, and sandy clay soils as Soil Class III.
Question 8: Soil Class IV is comprised of which soil textures?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt loam and clay loam
D. Silty clay and clay
CORRECT ANSWER: D. Silty clay and clay
Rationale: 30 TAC §285.30(b)(1)(A)(v) defines Soil Class IV as including silty
clay and clay soils.
Question 9: When Class II or Class III soils contain gravel, what
additional analysis must be performed?
A. A permeability test
B. A sieve analysis to determine gravel percentage by volume and size
C. A pH test
D. A compaction test
CORRECT ANSWER: B. A sieve analysis to determine gravel percentage
by volume and size
Rationale: 30 TAC §285.30(b)(1)(B) requires that Class II or Class III soils
containing gravel be further evaluated using a sieve analysis to determine
the percentage of gravel by volume and the size of the gravel.
, Question 10: Which of the following is considered a restrictive horizon
in soil analysis?
A. Sandy loam surface soil
B. Loamy sand subsoil
C. Clay subsoils, rock, and plugged laminar soils
D. Gravelly sandy loam
CORRECT ANSWER: C. Clay subsoils, rock, and plugged laminar soils
Rationale: 30 TAC §285.30(b)(1)(C) states that clay subsoils, rock, and
plugged laminar soils are considered restrictive horizons, recognized by an
abrupt change in texture from a sandy or loamy surface horizon.
Question 11: At what depth must the soil profile be examined for
indications of groundwater during a site evaluation?
A. Within 12 inches of the bottom of the excavation
B. Within 18 inches of the bottom of the excavation
C. Within 24 inches of the bottom of the excavation
D. Within 36 inches of the bottom of the excavation
CORRECT ANSWER: C. Within 24 inches of the bottom of the excavation
Rationale: 30 TAC §285.30(b)(2) requires the soil profile to be examined to
determine if there are indications of groundwater within 24 inches of the
bottom of the excavation.
Question 12: If the designated representative and the site evaluator
disagree on the presence of groundwater, what resource must the
designated representative use to verify groundwater information?
A. United States Geological Survey (USGS) topographic maps
B. Natural Resources Conservation Service (NRCS) soil survey for that
county, if available
C. Texas Water Development Board groundwater reports
D. Local well driller records
CORRECT ANSWER: B. Natural Resources Conservation Service (NRCS)
soil survey for that county, if available
Rationale: 30 TAC §285.30(b)(2)(A) specifies that if the designated
representative and the site evaluator disagree on groundwater presence,
Evaluator License Exam Study Guide & Practice
Questions | Soil Analysis, Site Evaluation, Septic
Systems, Groundwater, Soil Classification & Texas
OSSF Regulations
Question 1: According to 30 TAC §285.30, who is authorized to perform
a complete site evaluation on a tract of land where an OSSF will be
installed?
A. A licensed installer or apprentice
B. A designated representative or maintenance provider
C. A site evaluator or professional engineer
D. A homeowner or registered sanitarian
CORRECT ANSWER: C. A site evaluator or professional engineer
Rationale: 30 TAC §285.30(a) explicitly requires that a complete site
evaluation be performed by either a site evaluator or a professional
engineer, and a report documenting the evaluation must be submitted with
the planning materials.
Question 2: When conducting a soil analysis for a site evaluation, how
many soil borings or backhoe pits must be drilled or excavated at
minimum?
A. One boring at the center of the proposed disposal area
B. Two borings at opposite ends of the proposed disposal area
C. Three borings evenly spaced across the site
D. Four borings at each corner of the property
CORRECT ANSWER: B. Two borings at opposite ends of the proposed
disposal area
Rationale: 30 TAC §285.30(b)(1) mandates that the site evaluator drill two
soil borings or excavate two backhoe pits at opposite ends of the proposed
disposal area to determine soil characteristics.
Question 3: To what depth must soil borings or backhoe pits be
excavated during a site evaluation?
A. Six inches below the proposed excavation
B. One foot below the proposed excavation
C. Two feet below the adopted excavation or to a restrictive horizon,
,whichever is less
D. Three feet below the adopted excavation regardless of soil conditions
CORRECT ANSWER: C. Two feet below the adopted excavation or to a
restrictive horizon, whichever is less
Rationale: 30 TAC §285.30(b)(1) specifies that borings or backhoe pits shall
be excavated to a depth of two feet below the adopted excavation of the
disposal area, or to a restrictive horizon, whichever is less.
Question 4: Which soil class includes sandy textured soils that contain
more than 30% gravel?
A. Soil Class Ia
B. Soil Class Ib
C. Soil Class II
D. Soil Class III
CORRECT ANSWER: A. Soil Class Ia
Rationale: According to 30 TAC §285.30(b)(1)(A)(i), Soil Class Ia includes
sandy textured soils containing more than 30% gravel.
Question 5: Soil Class Ib soils are defined as sand and loamy sand soils
containing what percentage of gravel?
A. More than 30%
B. Less than or equal to 30%
C. Between 10% and 50%
D. Exactly 0%
CORRECT ANSWER: B. Less than or equal to 30%
Rationale: 30 TAC §285.30(b)(1)(A)(ii) defines Soil Class Ib as sand and
loamy sand soils that contain less than or equal to 30% gravel.
Question 6: Which of the following soil textures is classified as Soil
Class II?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt loam and silty clay loam
D. Silty clay and clay
CORRECT ANSWER: B. Sandy loam and loam
,Rationale: Soil Class II includes sandy loam and loam soils as specified in
30 TAC §285.30(b)(1)(A)(iii).
Question 7: Soil Class III includes which of the following soil textures?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt, silt loam, silty clay loam, clay loam, sandy clay loam, and sandy
clay
D. Silty clay and clay
CORRECT ANSWER: C. Silt, silt loam, silty clay loam, clay loam, sandy
clay loam, and sandy clay
Rationale: 30 TAC §285.30(b)(1)(A)(iv) classifies silt, silt loam, silty clay
loam, clay loam, sandy clay loam, and sandy clay soils as Soil Class III.
Question 8: Soil Class IV is comprised of which soil textures?
A. Sand and loamy sand
B. Sandy loam and loam
C. Silt loam and clay loam
D. Silty clay and clay
CORRECT ANSWER: D. Silty clay and clay
Rationale: 30 TAC §285.30(b)(1)(A)(v) defines Soil Class IV as including silty
clay and clay soils.
Question 9: When Class II or Class III soils contain gravel, what
additional analysis must be performed?
A. A permeability test
B. A sieve analysis to determine gravel percentage by volume and size
C. A pH test
D. A compaction test
CORRECT ANSWER: B. A sieve analysis to determine gravel percentage
by volume and size
Rationale: 30 TAC §285.30(b)(1)(B) requires that Class II or Class III soils
containing gravel be further evaluated using a sieve analysis to determine
the percentage of gravel by volume and the size of the gravel.
, Question 10: Which of the following is considered a restrictive horizon
in soil analysis?
A. Sandy loam surface soil
B. Loamy sand subsoil
C. Clay subsoils, rock, and plugged laminar soils
D. Gravelly sandy loam
CORRECT ANSWER: C. Clay subsoils, rock, and plugged laminar soils
Rationale: 30 TAC §285.30(b)(1)(C) states that clay subsoils, rock, and
plugged laminar soils are considered restrictive horizons, recognized by an
abrupt change in texture from a sandy or loamy surface horizon.
Question 11: At what depth must the soil profile be examined for
indications of groundwater during a site evaluation?
A. Within 12 inches of the bottom of the excavation
B. Within 18 inches of the bottom of the excavation
C. Within 24 inches of the bottom of the excavation
D. Within 36 inches of the bottom of the excavation
CORRECT ANSWER: C. Within 24 inches of the bottom of the excavation
Rationale: 30 TAC §285.30(b)(2) requires the soil profile to be examined to
determine if there are indications of groundwater within 24 inches of the
bottom of the excavation.
Question 12: If the designated representative and the site evaluator
disagree on the presence of groundwater, what resource must the
designated representative use to verify groundwater information?
A. United States Geological Survey (USGS) topographic maps
B. Natural Resources Conservation Service (NRCS) soil survey for that
county, if available
C. Texas Water Development Board groundwater reports
D. Local well driller records
CORRECT ANSWER: B. Natural Resources Conservation Service (NRCS)
soil survey for that county, if available
Rationale: 30 TAC §285.30(b)(2)(A) specifies that if the designated
representative and the site evaluator disagree on groundwater presence,
