TEXAS ON – SITE SEWAGE FACILITIES (OSSF)
EXAM QUESTIONS AND CORRECT ANSWERS
LATEST GUIDE 2026 .
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, 1. Acceptable ✓✓ correct answer is a condition in which a component is performing its intended purpose and is considered to be in an
operable state.
2. Adsorption ✓✓ correct answer allows contaminants in wastewater to bond with media particles to slow the rate of movement through the
media and to allow uptake of nutrients by plants and microorganisms in the media.
3. Aerobic ✓✓ correct answer is a condition where oxygen is required. Aerobic microorganisms require oxygen to live and breakdown pathogens
in wastewater.
4. Alkalinity ✓✓ correct answer refers to a wastewater's ability, or inability, to neutralize acids.
5. Ammonia ✓✓ correct answer is a compound of nitrogen and hydrogen with the formula NH3. The main uses of ammonia are in
the production of fertilizers, and it is also an ingredient in certain household glass cleaners. The form of nitrogen in septic tanks is ammonium.
6. Anaerobic ✓✓ correct answer is a condition in which there is no oxygen present. Anaerobic organisms get their oxygen supply by
breaking down chemical compounds that contain oxygen.
7. Aquifer ✓✓ correct answer is a geological formation that can store, transmit, and yield water to a well or spring.
8. Assimilation ✓✓ correct answer is the transformation of a nutrient into another form that can be digested by an organism.
9. Biochemical ✓✓ correct answer is a treatment process that combines biological treatment and chemical treatment. The two
processes overlap and sometimes it is hard to distinguish which treatment activities are biological and which are chemical.
10. Biochemical Oxygen Demand (BOD5) ✓✓ correct answer is the amount of oxygen consumed by microbes during
the decomposition of organic matter. It is an indicator of the overall strength of the wastewater.
11. Biological oxidation ✓✓ correct answer occurs when bacteria break down organic matter into water and carbon dioxide (CO2).
Oxidation reduces BOD5, removes pathogens, and works best under aerobic conditions.
12. Biological processes ✓✓ correct answer for treatment include natural die-ott, predation, biological oxidation, and mineral- ization.
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EXAM QUESTIONS AND CORRECT ANSWERS
LATEST GUIDE 2026 .
1/
11
, 1. Acceptable ✓✓ correct answer is a condition in which a component is performing its intended purpose and is considered to be in an
operable state.
2. Adsorption ✓✓ correct answer allows contaminants in wastewater to bond with media particles to slow the rate of movement through the
media and to allow uptake of nutrients by plants and microorganisms in the media.
3. Aerobic ✓✓ correct answer is a condition where oxygen is required. Aerobic microorganisms require oxygen to live and breakdown pathogens
in wastewater.
4. Alkalinity ✓✓ correct answer refers to a wastewater's ability, or inability, to neutralize acids.
5. Ammonia ✓✓ correct answer is a compound of nitrogen and hydrogen with the formula NH3. The main uses of ammonia are in
the production of fertilizers, and it is also an ingredient in certain household glass cleaners. The form of nitrogen in septic tanks is ammonium.
6. Anaerobic ✓✓ correct answer is a condition in which there is no oxygen present. Anaerobic organisms get their oxygen supply by
breaking down chemical compounds that contain oxygen.
7. Aquifer ✓✓ correct answer is a geological formation that can store, transmit, and yield water to a well or spring.
8. Assimilation ✓✓ correct answer is the transformation of a nutrient into another form that can be digested by an organism.
9. Biochemical ✓✓ correct answer is a treatment process that combines biological treatment and chemical treatment. The two
processes overlap and sometimes it is hard to distinguish which treatment activities are biological and which are chemical.
10. Biochemical Oxygen Demand (BOD5) ✓✓ correct answer is the amount of oxygen consumed by microbes during
the decomposition of organic matter. It is an indicator of the overall strength of the wastewater.
11. Biological oxidation ✓✓ correct answer occurs when bacteria break down organic matter into water and carbon dioxide (CO2).
Oxidation reduces BOD5, removes pathogens, and works best under aerobic conditions.
12. Biological processes ✓✓ correct answer for treatment include natural die-ott, predation, biological oxidation, and mineral- ization.
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