Level 1 Practice Exam Questions And

Nunavut Wastewater Treatment Operator Level 1 Practice Exam Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of a wastewater treatment plant?
• To generate electricity
• To remove pollutants from wastewater
• To produce drinking water
• To store stormwater

Rationale: The main goal of a wastewater treatment plant is to remove

physical, chemical, and biological pollutants from wastewater before it is discharged safely into the environment.

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• What is BOD in wastewater treatment?
• Biological Oxidation Demand
• Biochemical Oxygen Demand
• Basic Oxidation Determinant
• Biochemical Oxidation Device

Rationale: BOD measures the amount of dissolved oxygen needed by

microorganisms to break down organic matter in water. It indicates the level of organic pollution.

• Which stage of treatment primarily removes suspended solids?
• Tertiary treatment
• Disinfection
• Primary treatment
• Biological treatment

Rationale: Primary treatment uses sedimentation to remove large particles

and suspended solids from wastewater.

• What is the main role of aeration in activated sludge processes?
• Remove heavy metals
• Supply oxygen to microorganisms
• Settle solids
• Neutralize pH 2 / 4

Rationale: Aeration provides oxygen for bacteria to break down organic

matter in the activated sludge process.

5. Chlorine is most commonly used in wastewater treatment for:

• Flocculation
• Filtration
• Disinfection
• Sludge digestion

Rationale: Chlorine kills or inactivates pathogens, making wastewater safe

for discharge.

6. The pH of wastewater is important because:

• It affects only taste
• It has no impact
• It influences chemical reactions and biological processes
• It measures flow rate

Rationale: pH affects microbial activity and the efficiency of chemical

treatments like coagulation and disinfection.

• Which of the following is considered a secondary treatment process?
• Screening
• Activated sludge 3 / 4

• Grit removal
• Chlorination

Rationale: Secondary treatment focuses on biological removal of dissolved

and suspended organic matter.

8. The purpose of a grit chamber is to:

• Remove dissolved organics
• Remove sand, gravel, and other heavy inorganic solids
• Increase BOD
• Add chemicals

Rationale: Grit chambers prevent abrasion and clogging of pumps and

equipment by settling out heavy, inorganic solids.

9. Sludge from wastewater treatment plants is usually:

• Burned immediately
• Thickened, digested, and dewatered
• Released into rivers
• Used directly as fertilizer without treatment

Rationale: Sludge must be stabilized and dewatered before disposal or reuse

to reduce pathogens and odors.

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