Exam Practice Questions And Correct

Utah Wastewater Operator Class I Exam Practice Questions And Correct Answers (Verified Answers) Plus Rationales 2026 Q&A | Instant Download Pdf

• What is the primary purpose of preliminary treatment in a wastewater

treatment plant?

• Remove dissolved nutrients
• Remove organic solids
• Remove large solids and debris
• Disinfect wastewater

Rationale: Preliminary treatment is designed to remove large solids,

grit, and debris to protect downstream equipment and processes.

• Which process is commonly used to settle suspended solids in

wastewater? 1 / 4

• Filtration
• Sedimentation
• Aeration
• Disinfection

Rationale: Sedimentation allows heavier suspended solids to settle

by gravity in clarifiers or settling tanks.

• What is the typical pH range of influent municipal wastewater?

A. 2.0–4.0

B. 5.0–6.0

C. 6.5–8.5

D. 9.0–11.0

Rationale: Most municipal wastewater has a near-neutral pH range,

typically between 6.5 and 8.5.

• In activated sludge processes, what is the purpose of aeration?
• Remove grit
• Settle solids
• Provide oxygen for microbial degradation
• Remove heavy metals

Rationale: Aeration supplies oxygen to microorganisms to break

down organic matter in wastewater.

• What is BOD an indicator of in wastewater?
• Inorganic solids
• Organic pollution 2 / 4

• Heavy metals
• pH

Rationale: Biochemical Oxygen Demand (BOD) measures the amount

of oxygen required by microorganisms to decompose organic matter.

• Which of the following is a primary disinfection method in wastewater

treatment?

• Filtration
• Coagulation
• Chlorination
• Sedimentation

Rationale: Chlorination is a common method used to disinfect

treated wastewater before discharge.

• What does TSS stand for?
• Total soluble solids
• Typical suspended solids
• Total suspended solids
• Total sanitary solids

Rationale: TSS measures the concentration of suspended particles in

wastewater.

• In lagoon treatment, what role does algae play?
• Remove grit
• Cause sedimentation
• Produce oxygen for microorganisms 3 / 4

• Neutralize pH

Rationale: Algae generate oxygen through photosynthesis, which

helps aerobic bacteria degrade organic matter in lagoons.

• Which unit operation is used primarily for nutrient removal?
• Sedimentation
• Screening
• Biological nutrient removal (BNR)
• Disinfection

Rationale: BNR processes are designed to remove nitrogen and

phosphorus biologically.

• What safety equipment is essential when handling chlorine gas?
• Safety goggles only
• Respirator and gas detection
• Ear plugs
• Hard hat only

Rationale: Chlorine gas is toxic; proper respiratory protection and

gas detection are mandatory.

11. The sludge collected from primary clarifiers is known as:

• Activated sludge
• Primary sludge
• Secondary sludge
• Digested sludge
• / 4