Texas Wastewater Class D Unit Test Exam
Newest With Complete Questions And
Correct Detailed Answers| Brand New
Version!2026 2027
1. What is the primary purpose of a wastewater
treatment plant?
To disinfect drinking water
To remove pollutants from wastewater
To supply water pressure
To store stormwater
Wastewater treatment plants are designed to
remove contaminants before discharge.
2. Which agency regulates wastewater treatment in
Texas?
EPA
TCEQ
OSHA
CDC
The Texas Commission on Environmental Quality
oversees wastewater operations.
3. What does BOD stand for?
Biological Oxygen Demand
, Biochemical Oxygen Demand
Bacterial Oxygen Deficit
Base Oxygen Demand
BOD measures the amount of oxygen required by
microorganisms to break down organic matter.
4. High BOD levels indicate:
Low organic matter
High organic pollution
High chlorine levels
Clean effluent
High BOD means more oxygen is needed due to
organic waste.
5. Which process removes large solids first?
Secondary treatment
Disinfection
Preliminary treatment
Tertiary treatment
Preliminary treatment removes rags, grit, and
large debris.
6. Bar screens are used to remove:
Dissolved solids
Bacteria
Large debris
, Grease
Bar screens trap rags, sticks, and trash.
7. Grit chambers remove:
Organic waste
Sand and gravel
Oil and grease
Bacteria
Grit chambers protect equipment from abrasive
materials.
8. Primary treatment mainly removes:
Dissolved solids
Settleable solids
Nutrients
Pathogens
Primary clarifiers allow solids to settle by gravity.
9. Sludge from primary treatment is called:
Activated sludge
Primary sludge
Scum
Effluent
Solids settled in primary clarifiers are primary
sludge.
Newest With Complete Questions And
Correct Detailed Answers| Brand New
Version!2026 2027
1. What is the primary purpose of a wastewater
treatment plant?
To disinfect drinking water
To remove pollutants from wastewater
To supply water pressure
To store stormwater
Wastewater treatment plants are designed to
remove contaminants before discharge.
2. Which agency regulates wastewater treatment in
Texas?
EPA
TCEQ
OSHA
CDC
The Texas Commission on Environmental Quality
oversees wastewater operations.
3. What does BOD stand for?
Biological Oxygen Demand
, Biochemical Oxygen Demand
Bacterial Oxygen Deficit
Base Oxygen Demand
BOD measures the amount of oxygen required by
microorganisms to break down organic matter.
4. High BOD levels indicate:
Low organic matter
High organic pollution
High chlorine levels
Clean effluent
High BOD means more oxygen is needed due to
organic waste.
5. Which process removes large solids first?
Secondary treatment
Disinfection
Preliminary treatment
Tertiary treatment
Preliminary treatment removes rags, grit, and
large debris.
6. Bar screens are used to remove:
Dissolved solids
Bacteria
Large debris
, Grease
Bar screens trap rags, sticks, and trash.
7. Grit chambers remove:
Organic waste
Sand and gravel
Oil and grease
Bacteria
Grit chambers protect equipment from abrasive
materials.
8. Primary treatment mainly removes:
Dissolved solids
Settleable solids
Nutrients
Pathogens
Primary clarifiers allow solids to settle by gravity.
9. Sludge from primary treatment is called:
Activated sludge
Primary sludge
Scum
Effluent
Solids settled in primary clarifiers are primary
sludge.
