Minnesota Small Public Water Supply
Operator Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. What is the primary responsibility of a small public water supply
operator?
A. Increasing water pressure for all customers
B. Ensuring safe and reliable drinking water is provided to the public
C. Reducing all water treatment costs
D. Eliminating all maintenance activities
Answer: B. Ensuring safe and reliable drinking water is provided to the
public
,Rationale: The operator’s main duty is protecting public health by
operating and maintaining the water system so that drinking water meets
safety requirements.
2. Which Minnesota agency regulates public drinking water systems?
A. Minnesota Department of Transportation
B. Minnesota Department of Agriculture
C. Minnesota Department of Health
D. Minnesota Pollution Control Agency
Answer: C. Minnesota Department of Health
Rationale: The Minnesota Department of Health oversees public water
systems and enforces drinking water regulations to protect public health.
3. A public water supply system must monitor water quality primarily to:
A. Increase customer complaints
B. Verify treatment and safety requirements are being met
C. Reduce the number of employees
D. Improve billing accuracy
Answer: B. Verify treatment and safety requirements are being met
Rationale: Monitoring confirms that the water system is operating
correctly and that contaminants remain below regulatory limits.
, 4. The main purpose of chlorine disinfection is to:
A. Remove hardness
B. Increase alkalinity
C. Destroy or inactivate harmful microorganisms
D. Remove all dissolved minerals
Answer: C. Destroy or inactivate harmful microorganisms
Rationale: Chlorine is used as a disinfectant to control bacteria, viruses,
and other disease-causing organisms in drinking water.
5. The amount of chlorine remaining in water after demand has been
satisfied is called:
A. Chlorine demand
B. Residual chlorine
C. Combined solids
D. Turbidity level
Answer: B. Residual chlorine
Rationale: Chlorine residual is the chlorine available after reactions with
contaminants and is used to maintain protection throughout the
distribution system.
6. Turbidity in drinking water is a measurement of:
, A. Water temperature
B. Cloudiness caused by suspended particles
C. Chlorine concentration
D. Water hardness
Answer: B. Cloudiness caused by suspended particles
Rationale: Turbidity measures the presence of suspended particles that
can affect appearance and interfere with disinfection.
7. A cross-connection is:
A. A connection between two unrelated water systems or substances
B. A broken pipe underground
C. A water meter failure
D. A storage tank overflow
Answer: A. A connection between two unrelated water systems or
substances
Rationale: Cross-connections can allow contaminants to enter drinking
water systems through backflow.
8. Backflow occurs when:
A. Water pressure forces contaminants into the system
B. Water evaporates from storage tanks
Operator Exam Practice Questions And
Correct Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. What is the primary responsibility of a small public water supply
operator?
A. Increasing water pressure for all customers
B. Ensuring safe and reliable drinking water is provided to the public
C. Reducing all water treatment costs
D. Eliminating all maintenance activities
Answer: B. Ensuring safe and reliable drinking water is provided to the
public
,Rationale: The operator’s main duty is protecting public health by
operating and maintaining the water system so that drinking water meets
safety requirements.
2. Which Minnesota agency regulates public drinking water systems?
A. Minnesota Department of Transportation
B. Minnesota Department of Agriculture
C. Minnesota Department of Health
D. Minnesota Pollution Control Agency
Answer: C. Minnesota Department of Health
Rationale: The Minnesota Department of Health oversees public water
systems and enforces drinking water regulations to protect public health.
3. A public water supply system must monitor water quality primarily to:
A. Increase customer complaints
B. Verify treatment and safety requirements are being met
C. Reduce the number of employees
D. Improve billing accuracy
Answer: B. Verify treatment and safety requirements are being met
Rationale: Monitoring confirms that the water system is operating
correctly and that contaminants remain below regulatory limits.
, 4. The main purpose of chlorine disinfection is to:
A. Remove hardness
B. Increase alkalinity
C. Destroy or inactivate harmful microorganisms
D. Remove all dissolved minerals
Answer: C. Destroy or inactivate harmful microorganisms
Rationale: Chlorine is used as a disinfectant to control bacteria, viruses,
and other disease-causing organisms in drinking water.
5. The amount of chlorine remaining in water after demand has been
satisfied is called:
A. Chlorine demand
B. Residual chlorine
C. Combined solids
D. Turbidity level
Answer: B. Residual chlorine
Rationale: Chlorine residual is the chlorine available after reactions with
contaminants and is used to maintain protection throughout the
distribution system.
6. Turbidity in drinking water is a measurement of:
, A. Water temperature
B. Cloudiness caused by suspended particles
C. Chlorine concentration
D. Water hardness
Answer: B. Cloudiness caused by suspended particles
Rationale: Turbidity measures the presence of suspended particles that
can affect appearance and interfere with disinfection.
7. A cross-connection is:
A. A connection between two unrelated water systems or substances
B. A broken pipe underground
C. A water meter failure
D. A storage tank overflow
Answer: A. A connection between two unrelated water systems or
substances
Rationale: Cross-connections can allow contaminants to enter drinking
water systems through backflow.
8. Backflow occurs when:
A. Water pressure forces contaminants into the system
B. Water evaporates from storage tanks
