OSSF Designated Representative / Texas OSSF Rules &
Installation Standards for Wastewater Treatment
Study Set
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Exam Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!!
Current Update!!
1. A site evaluation can be completed by: - ANSWER A licensed site
evaluator or a PE
2. A site evaluation must include: - ANSWER - Soil analysis
- Groundwater evaluation
- Topography
- Flood hazard
- Separation requirements
3. What slopes are considered suitable? - ANSWER Less than 30%
4. How can surface water be diverted from an OSSF? - ANSWER Terraces,
berms, or swales
5. What is the best slope for surface drainage? - ANSWER 2-6%
,6. Why is vegetation important? - ANSWER - Helps to breakdown and
remove nitrogen
- Prevents erosion
- Roots open channels in soil matrix for water to follow
- Evapotranspiration
7. Zone of aeration: - ANSWER The area where the pores of soil are
partially filled with water
8. Zone of saturation: - ANSWER The area where the pores of soil are
completely filled with water - this is the zone of well water
9. Aquifers - ANSWER Portions of the saturation zone that produce an
abundance of water. Can be found in unconsolidated rock, fractured rock,
sandstone beds, open caverns in limestone
10.Regions with 40 systems per square mile have a higher potential for what? -
ANSWER Groundwater contamination
11.The Edwards Aquifer is a special class of aquifer called: - ANSWER Karst -
very productive aquifer formed when water dissolves limestone and makes
existing fractures larger
12.Special rules considering systems in the Edwards Aquifer Recharge Zone are:
- ANSWER No tanks within 50', no soil absorption systems within 150'
,13.The four major components of soil - ANSWER Inorganic matter, organic
matter, water, air
14.5 major soil-forming factors - ANSWER parent materials, climate, biota,
topography, time
15.Soil permeability (hydraulic conductivity) - ANSWER the ability of soil to
transport water through a soil under either saturated or unsaturated
conditions
16.Why is aeration important? - ANSWER achieves maximum
decomposition of organics and destruction of harmful bacteria and viruses.
Encourages aerobic microflora to grow
17.Soil profile - ANSWER All the vertical layers or horizons that make up a
soil in a particular place
18.major horizons of soil - ANSWER A - surface soil containing decomposed
organic mater, darker color
B - subsoil containing deposits of clay, iron, aluminum, and humus creating
blocky structure, redder or browner colors
C - substratum (parent material) containing minerals and parent material, is
little affected by soil forming process.
19.Soil materials greater than 2mm - ANSWER Gravel
, 20.Sandy soil with 30% or more gravel - ANSWER Class Ia soil (unsuitable)
21.Class II and Class III soils with greater than 30% gravel - ANSWER 80% of
gravel must be less than 5mm to be suitable
22.Sand - ANSWER particles between 2mm-.05mm
23.Silt - ANSWER particles between .05mm-.002mm
24.Clay - ANSWER particles under .002mm
25.Particle size analysis - ANSWER The determination of the various
amounts of the different separates in a soil sample, usually by
sedimentation, sieving or micrometry or a combination of these methods.
26.mottling - ANSWER streaks of orange and brown on a background of
gray or bluish colors
27.Gley soil - ANSWER soil with strong mottling, indicates lack of oxygen
associated with seasonal or periodic water table (unsuitable)
28.Phosphorus transport occurs in soil that is: - ANSWER coarse-textured,
slightly acidic, very low organic matter
Installation Standards for Wastewater Treatment
Study Set
Comprehensive Resource To Help You Ace 2026-2027
Includes Frequently Tested Exam Questions With
ELABORATED 100% Correct COMPLETE SOLUTIONS
Guaranteed Pass First Attempt!!
Current Update!!
1. A site evaluation can be completed by: - ANSWER A licensed site
evaluator or a PE
2. A site evaluation must include: - ANSWER - Soil analysis
- Groundwater evaluation
- Topography
- Flood hazard
- Separation requirements
3. What slopes are considered suitable? - ANSWER Less than 30%
4. How can surface water be diverted from an OSSF? - ANSWER Terraces,
berms, or swales
5. What is the best slope for surface drainage? - ANSWER 2-6%
,6. Why is vegetation important? - ANSWER - Helps to breakdown and
remove nitrogen
- Prevents erosion
- Roots open channels in soil matrix for water to follow
- Evapotranspiration
7. Zone of aeration: - ANSWER The area where the pores of soil are
partially filled with water
8. Zone of saturation: - ANSWER The area where the pores of soil are
completely filled with water - this is the zone of well water
9. Aquifers - ANSWER Portions of the saturation zone that produce an
abundance of water. Can be found in unconsolidated rock, fractured rock,
sandstone beds, open caverns in limestone
10.Regions with 40 systems per square mile have a higher potential for what? -
ANSWER Groundwater contamination
11.The Edwards Aquifer is a special class of aquifer called: - ANSWER Karst -
very productive aquifer formed when water dissolves limestone and makes
existing fractures larger
12.Special rules considering systems in the Edwards Aquifer Recharge Zone are:
- ANSWER No tanks within 50', no soil absorption systems within 150'
,13.The four major components of soil - ANSWER Inorganic matter, organic
matter, water, air
14.5 major soil-forming factors - ANSWER parent materials, climate, biota,
topography, time
15.Soil permeability (hydraulic conductivity) - ANSWER the ability of soil to
transport water through a soil under either saturated or unsaturated
conditions
16.Why is aeration important? - ANSWER achieves maximum
decomposition of organics and destruction of harmful bacteria and viruses.
Encourages aerobic microflora to grow
17.Soil profile - ANSWER All the vertical layers or horizons that make up a
soil in a particular place
18.major horizons of soil - ANSWER A - surface soil containing decomposed
organic mater, darker color
B - subsoil containing deposits of clay, iron, aluminum, and humus creating
blocky structure, redder or browner colors
C - substratum (parent material) containing minerals and parent material, is
little affected by soil forming process.
19.Soil materials greater than 2mm - ANSWER Gravel
, 20.Sandy soil with 30% or more gravel - ANSWER Class Ia soil (unsuitable)
21.Class II and Class III soils with greater than 30% gravel - ANSWER 80% of
gravel must be less than 5mm to be suitable
22.Sand - ANSWER particles between 2mm-.05mm
23.Silt - ANSWER particles between .05mm-.002mm
24.Clay - ANSWER particles under .002mm
25.Particle size analysis - ANSWER The determination of the various
amounts of the different separates in a soil sample, usually by
sedimentation, sieving or micrometry or a combination of these methods.
26.mottling - ANSWER streaks of orange and brown on a background of
gray or bluish colors
27.Gley soil - ANSWER soil with strong mottling, indicates lack of oxygen
associated with seasonal or periodic water table (unsuitable)
28.Phosphorus transport occurs in soil that is: - ANSWER coarse-textured,
slightly acidic, very low organic matter
