Operator Level 1 Exam Practice Questions

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

• What is the primary purpose of a wastewater treatment plant?

a) Produce drinking water

b) Generate electricity

c) Remove contaminants from wastewater before discharge

d) Provide irrigation water

Rationale: The main function of a wastewater treatment plant is to

remove physical, chemical, and biological contaminants from wastewater to protect public health and the environment.

• Which of the following is a common physical treatment process in

wastewater treatment?

a) Biological nutrient removal 1 / 4

b) Sedimentation

c) Disinfection

d) Filtration

Rationale: Sedimentation is a physical process where solids settle out

of wastewater by gravity.

• What type of wastewater is typically treated at a Level 1 wastewater

facility?

a) Industrial effluent only

b) Municipal wastewater with low-strength characteristics

c) High-strength industrial wastewater

d) Stormwater only

Rationale: Level 1 facilities usually handle domestic or municipal

wastewater that is relatively low in strength.

• What is the function of screening in wastewater treatment?

a) Kill bacteria

b) Settle solids

c) Remove large debris

d) Remove dissolved chemicals

Rationale: Screening removes large objects such as sticks, rags, and

plastics to prevent damage to equipment downstream.

• In a typical wastewater treatment plant, which unit removes

settleable solids?

a) Aeration tank 2 / 4

b) Trickling filter

c) Primary clarifier

d) Disinfection chamber

Rationale: The primary clarifier allows heavier solids to settle out by

gravity.

• Which process is considered a biological treatment method?

a) Screening

b) Sedimentation

c) Activated sludge

d) Chlorination

Rationale: Activated sludge uses microorganisms to biologically

degrade organic matter.

• What is BOD (Biochemical Oxygen Demand) a measure of?
• pH level

b) The amount of oxygen required to break down organic matter

c) Total suspended solids

d) Heavy metals concentration

Rationale: BOD measures the oxygen needed by bacteria to

decompose organic material in water.

• Which of the following is a common disinfectant used in wastewater

treatment?

a) Ozone only

b) UV light only 3 / 4

c) Chlorine

d) Hydrogen peroxide

Rationale: Chlorine is widely used for disinfection due to its

effectiveness and relatively low cost.

• Why is pH control important in wastewater treatment?

a) It removes solids

b) It reduces BOD

c) It maintains optimal conditions for biological processes

d) It disinfects water

Rationale: Microorganisms function best within a specific pH range;

extreme pH can inhibit treatment processes.

• What type of sludge results from primary sedimentation?

a) Secondary sludge

b) Tertiary sludge

c) Primary sludge

d) Digested sludge

Rationale: Primary sludge is the settled solids collected from the

primary clarifier.

• Which of the following best describes secondary treatment?

a) Removal of large debris

b) Biological removal of organic matter

c) Disinfection

d) Chemical coagulation

• / 4