Level 2 Exam Practice Questions And

Nunavut Wastewater Treatment Operator Level 2 Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• Which of the following is the primary purpose of wastewater

treatment?

• To increase water hardness
• To remove pathogens and contaminants
• To change the color of water
• To generate electricity
• To remove pathogens and contaminants

Rationale: The main goal of wastewater treatment is to remove

harmful microorganisms, chemicals, and solids to protect public health and the environment. 1 / 4

• What is the first stage of most wastewater treatment plants?
• Secondary treatment
• Tertiary treatment
• Primary treatment
• Disinfection
• Primary treatment

Rationale: Primary treatment involves physical processes like

screening and sedimentation to remove large solids.

• What is the purpose of a grit chamber?
• Remove dissolved chemicals
• Settle heavy inorganic particles
• Filter bacteria
• Aerate water
• Settle heavy inorganic particles

Rationale: Grit chambers allow sand, gravel, and other dense

particles to settle out before biological treatment, preventing equipment damage.

• Which microorganism is commonly used in activated sludge systems?
• Algae
• Protozoa
• Bacteria
• Viruses
• Bacteria 2 / 4

Rationale: Bacteria break down organic matter in wastewater during

biological treatment.

5. In wastewater treatment, BOD stands for:

• Biological Oxidation Demand
• Biochemical Oxygen Demand
• Biological Oxygen Distribution
• Biochemical Oxidation Density
• Biochemical Oxygen Demand

Rationale: BOD measures the amount of oxygen microorganisms

need to decompose organic matter, indicating wastewater strength.

• What is the function of a clarifier in wastewater treatment?
• Add chemicals to disinfect water
• Remove settleable solids from wastewater
• Increase water pH
• Remove dissolved oxygen
• Remove settleable solids from wastewater

Rationale: Clarifiers allow solids to settle by gravity, separating

sludge from the treated water.

• What type of treatment is sand filtration?
• Primary
• Secondary
• Tertiary
• Quaternary 3 / 4

• Tertiary

Rationale: Sand filtration is a tertiary treatment method that

removes fine suspended solids after primary and secondary treatment.

• What is the typical range of pH for effective wastewater treatment?

A. 2–4

B. 6.5–8.5

C. 9–11

D. 12–14

B. 6.5–8.5

Rationale: A pH between 6.5 and 8.5 is optimal for microbial activity

and chemical treatment processes.

• Which of the following is a common method of sludge disposal?
• Land application
• Flocculation
• Coagulation
• Chlorination
• Land application

Rationale: Sludge can be treated and applied to land as fertilizer,

reducing waste and returning nutrients to soil.

10. Nitrification in wastewater treatment converts:

• Ammonia to nitrate
• Nitrite to ammonia
• / 4