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Nevada Water Distribution Operator Level I
Certification ACTUAL QUESTIONS AND
ANSWERS LATEST UPDATE THIS YEAR
Nevada Water Distribution Operator Level I Certification – Summarized Exam Coverage
Based on the Nevada Administrative Code (NAC), the NDEP Drinking Water Operator
Certification Program, and the Association of Boards of Certification (ABC) standardized
approach, the exam tests the knowledge and skills required for entry-level water distribution
system operation and maintenance. The following summary organizes the six major subject
areas that regularly appear on the Grade 1 Distribution exam.
I. Distribution System Components & Equipment
• Pipes, valves, hydrants, pumps, motors – basic identification, function, and operation
• Storage facilities – elevated tanks, ground-level reservoirs, standpipes, hydropneumatic
tanks
• Meters and flow measurement – types, purpose, and basic sizing
• System classification – Distribution-1 through Distribution-4 based on population,
pressure zones, storage, pumping stations, disinfection, SCADA, and recycled water
systems
• Minimum cover – water mains must be installed with at least 36 inches of cover or at
least 12 inches below frost depth, whichever is deeper
II. Install, Operate & Maintain (IOM)
• Installation and connection – tapping, disinfection, testing, and connecting water
mains and appurtenances
• Maintenance activities – flushing, cleaning, pigging, and rehabilitating existing water
mains
• Emergency response – shutdown, repair, disinfection, and testing of broken water
mains
• Well maintenance – pulling, resetting, rehabilitating, disinfecting, and testing water
wells
• Reservoir maintenance – draining, cleaning, disinfecting, and maintaining distribution
reservoirs
• Standby emergency duties – after-hours emergency response for distribution system
operation
III. Monitor, Evaluate & Adjust (MEA)
• SCADA system monitoring – pressure, flow, chlorine residual, tank levels, and system
status
• Water quality parameters – chlorine residual (DPD method), pH, turbidity, coliform
bacteria
• Pressure management – residual pressure requirements ( ≥ 40 psi during maximum day
demand, ≥ 30 psi during peak hour demand, ≥ 20 psi during fire flow conditions)
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• Velocity control – maintain normal water velocities at approximately 8 feet per second
during all conditions other than fire flow
• Fire flow – storage capacity for fire demand calculated according to fire authority
requirements
• Storage turnover – monitor turnover rates to prevent bacterial stagnation
IV. Disinfection & Laboratory
• Chlorine residual testing – DPD colorimetric method; free chlorine residual at farthest
point of the system
• Dechlorination – methods and purposes (sodium bisulfite, sulfur dioxide, ascorbic acid)
• Bacteriological sampling – coliform sampling procedures, sample transportation (1–
10°C), hold times
• New main disinfection – AWWA Standard C651; coliform analysis required before
placing into service
• Decontamination – procedures for equipment and sample bottles (sodium thiosulfate)
V. Safety & Security Procedures
• Confined space entry – atmospheric testing (O₂, LEL, H₂S, CO), permit, attendant,
retrieval system
• Lockout/Tagout (LOTO) – de-energization, application of locks and tags, verification of
isolation
• Hazardous gases – chlorine safety, chlorine gas detector, ammonia swab test for small
leaks, H₂S awareness
• Chemical handling – PPE (chemical-resistant gloves, coveralls, goggles/face shield,
respirator), decontamination
• Cross-connection control – backflow prevention assemblies (RPZ, double check, air
gap), CCCP requirements (NAC 445A.6663, NAC 445A.67185 through NAC 445A.67195)
• Public interaction and records – recordkeeping requirements, public notification,
consumer confidence reports
VI. Administrative & Regulatory
• Nevada Administrative Code (NAC) – relevant sections: NAC 445A.6267, NAC
445A.6663, NAC 445A.67145, NAC 445A.6672, NAC 445A.6674
• Nevada Revised Statutes (NRS) – NRS 445A.875 through 445A.880 governing operator
certification
• Certification requirements – for a Distribution-1 facility, the person in responsible
charge, a supervisor or foreperson, and a shift operator must each have at least
Distribution-1 certification
• Experience requirement – Grade 1 certification requires 6 months of experience (plus
high school diploma or GED)
• Renewal – certificates must be renewed every two years with continuing education
credits
• Operator-in-Training (OIT) – provisional certification for those without required
experience
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QUESTION 1: A new distribution system is being classified as Distribution-1. What is the
minimum certification required for the person in responsible charge of this facility?
A) No certification required
B) Distribution-1 certification
C) Distribution-2 certification
D) Distribution-3 certification
Answer: B – NAC 445A.6267(2)(a)(1) requires the person in responsible charge of a
Distribution-1 facility to have at least Distribution-1 certification. The same certification
level is required for the supervisor and shift operator at a Distribution-1 facility.
QUESTION 2: Which type of storage facility is most effective for maintaining pressure in
a gravity-fed distribution system?
A) Ground-level reservoir
B) Elevated tank
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C) Hydropneumatic tank
D) Standpipe
Answer: B – Elevated tanks use height to create static pressure, ensuring a constant
pressure head to the distribution network without mechanical assistance.
QUESTION 3: When calculating static pressure at the outlet of a storage tank, what is
the most important factor?
A) Tank diameter
B) Water temperature
C) Elevation of the water surface above the outlet
D) Flow rate through the outlet
Answer: C – Static pressure equals the weight of the water column above the outlet;
thus, it depends on the elevation (head) of the water surface.
Nevada Water Distribution Operator Level I
Certification ACTUAL QUESTIONS AND
ANSWERS LATEST UPDATE THIS YEAR
Nevada Water Distribution Operator Level I Certification – Summarized Exam Coverage
Based on the Nevada Administrative Code (NAC), the NDEP Drinking Water Operator
Certification Program, and the Association of Boards of Certification (ABC) standardized
approach, the exam tests the knowledge and skills required for entry-level water distribution
system operation and maintenance. The following summary organizes the six major subject
areas that regularly appear on the Grade 1 Distribution exam.
I. Distribution System Components & Equipment
• Pipes, valves, hydrants, pumps, motors – basic identification, function, and operation
• Storage facilities – elevated tanks, ground-level reservoirs, standpipes, hydropneumatic
tanks
• Meters and flow measurement – types, purpose, and basic sizing
• System classification – Distribution-1 through Distribution-4 based on population,
pressure zones, storage, pumping stations, disinfection, SCADA, and recycled water
systems
• Minimum cover – water mains must be installed with at least 36 inches of cover or at
least 12 inches below frost depth, whichever is deeper
II. Install, Operate & Maintain (IOM)
• Installation and connection – tapping, disinfection, testing, and connecting water
mains and appurtenances
• Maintenance activities – flushing, cleaning, pigging, and rehabilitating existing water
mains
• Emergency response – shutdown, repair, disinfection, and testing of broken water
mains
• Well maintenance – pulling, resetting, rehabilitating, disinfecting, and testing water
wells
• Reservoir maintenance – draining, cleaning, disinfecting, and maintaining distribution
reservoirs
• Standby emergency duties – after-hours emergency response for distribution system
operation
III. Monitor, Evaluate & Adjust (MEA)
• SCADA system monitoring – pressure, flow, chlorine residual, tank levels, and system
status
• Water quality parameters – chlorine residual (DPD method), pH, turbidity, coliform
bacteria
• Pressure management – residual pressure requirements ( ≥ 40 psi during maximum day
demand, ≥ 30 psi during peak hour demand, ≥ 20 psi during fire flow conditions)
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• Velocity control – maintain normal water velocities at approximately 8 feet per second
during all conditions other than fire flow
• Fire flow – storage capacity for fire demand calculated according to fire authority
requirements
• Storage turnover – monitor turnover rates to prevent bacterial stagnation
IV. Disinfection & Laboratory
• Chlorine residual testing – DPD colorimetric method; free chlorine residual at farthest
point of the system
• Dechlorination – methods and purposes (sodium bisulfite, sulfur dioxide, ascorbic acid)
• Bacteriological sampling – coliform sampling procedures, sample transportation (1–
10°C), hold times
• New main disinfection – AWWA Standard C651; coliform analysis required before
placing into service
• Decontamination – procedures for equipment and sample bottles (sodium thiosulfate)
V. Safety & Security Procedures
• Confined space entry – atmospheric testing (O₂, LEL, H₂S, CO), permit, attendant,
retrieval system
• Lockout/Tagout (LOTO) – de-energization, application of locks and tags, verification of
isolation
• Hazardous gases – chlorine safety, chlorine gas detector, ammonia swab test for small
leaks, H₂S awareness
• Chemical handling – PPE (chemical-resistant gloves, coveralls, goggles/face shield,
respirator), decontamination
• Cross-connection control – backflow prevention assemblies (RPZ, double check, air
gap), CCCP requirements (NAC 445A.6663, NAC 445A.67185 through NAC 445A.67195)
• Public interaction and records – recordkeeping requirements, public notification,
consumer confidence reports
VI. Administrative & Regulatory
• Nevada Administrative Code (NAC) – relevant sections: NAC 445A.6267, NAC
445A.6663, NAC 445A.67145, NAC 445A.6672, NAC 445A.6674
• Nevada Revised Statutes (NRS) – NRS 445A.875 through 445A.880 governing operator
certification
• Certification requirements – for a Distribution-1 facility, the person in responsible
charge, a supervisor or foreperson, and a shift operator must each have at least
Distribution-1 certification
• Experience requirement – Grade 1 certification requires 6 months of experience (plus
high school diploma or GED)
• Renewal – certificates must be renewed every two years with continuing education
credits
• Operator-in-Training (OIT) – provisional certification for those without required
experience
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QUESTION 1: A new distribution system is being classified as Distribution-1. What is the
minimum certification required for the person in responsible charge of this facility?
A) No certification required
B) Distribution-1 certification
C) Distribution-2 certification
D) Distribution-3 certification
Answer: B – NAC 445A.6267(2)(a)(1) requires the person in responsible charge of a
Distribution-1 facility to have at least Distribution-1 certification. The same certification
level is required for the supervisor and shift operator at a Distribution-1 facility.
QUESTION 2: Which type of storage facility is most effective for maintaining pressure in
a gravity-fed distribution system?
A) Ground-level reservoir
B) Elevated tank
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C) Hydropneumatic tank
D) Standpipe
Answer: B – Elevated tanks use height to create static pressure, ensuring a constant
pressure head to the distribution network without mechanical assistance.
QUESTION 3: When calculating static pressure at the outlet of a storage tank, what is
the most important factor?
A) Tank diameter
B) Water temperature
C) Elevation of the water surface above the outlet
D) Flow rate through the outlet
Answer: C – Static pressure equals the weight of the water column above the outlet;
thus, it depends on the elevation (head) of the water surface.
