NGWA WATER SYSTEMS CERTIFICATION EXAM – QUESTIONS AND ANSWERS |
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED
PASS | LATEST EXAM UPDATE
CORE DOMAINS *
• Hydrogeology and Fluid Mechanics
• Well Drilling Methods and Design
• Water System Dynamics and Hydraulics
• Water Quality, Testing, and Treatment
• Pump Selection, Installation, and Maintenance
• Safety Standards and Hazardous Materials
• Regulatory Compliance and Environmental Law
• Professional Ethics and Business Practices
INTRODUCTION *
The NGWA Water Systems Certification Exam is a comprehensive assessment
designed to evaluate the critical knowledge, technical skills, and professional
competency required of water well system professionals. This exam ensures that
practitioners possess a thorough understanding of hydrogeology, well construction,
system design, and regulatory compliance. Featuring a mix of multiple-choice and
complex, scenario-based questions, the assessment places a heavy emphasis on
real-world application, diagnostics, and ethical decision-making. Candidates are tested
on their ability to analyze hydraulic data, troubleshoot system failures, and implement
, safe, efficient, and environmentally sound water delivery solutions under diverse field
conditions.
Question 1
Which type of aquifer is bounded above and below by impermeable layers, causing the
water within it to be under hydrostatic pressure?
A. Unconfined aquifer
B. Perched aquifer
C. Confined aquifer
D. Water table aquifer
🟢 C. Confined aquifer
🔴 Explanation: A confined aquifer is trapped between two impermeable layers (aquicludes
or aquitards), putting the water under pressure. If a well penetrates this layer, water rises
above the top of the aquifer.
Question 2
When sizing a residential submersible pump, what are the two primary parameters that must
be determined?
,A. Casing diameter and well depth
B. Total Dynamic Head (TDH) and Flow Rate (GPM)
C. Static water level and motor horsepower
D. Friction loss and voltage drop
🟢 B. Total Dynamic Head (TDH) and Flow Rate (GPM)
🔴 Explanation: Total Dynamic Head (TDH) and the required flow rate in Gallons Per Minute
(GPM) are the fundamental metrics needed to select a pump curve that operates efficiently.
Question 3
According to EPA National Primary Drinking Water Regulations, what is the Maximum
Contaminant Level (MCL) for Total Coliform bacteria in public water systems?
A. Less than 5% of monthly samples can be positive
B. Zero positive samples allowed annually
C. 10 parts per million
D. 1 count per 100 milliliters
🟢 A. Less than 5% of monthly samples can be positive
, 🔴 Explanation: For public water systems that collect 40 or more samples per month, no
more than 5.0% of the samples may be positive for total coliform. For systems collecting
fewer than 40 samples, no more than one sample can be positive.
Question 4
A multi-stage centrifugal submersible pump is experiencing a drop in capacity and pressure,
but the motor is drawing normal running amps. What is the most likely cause?
A. Motor running in reverse
B. Blown fuse on one line
C. Worn impellers or blocked intake
D. Voltage drop in the drop cable
🟢 C. Worn impellers or blocked intake
🔴 Explanation: A drop in both capacity and pressure with normal current draw typically
points to mechanical wear of the impellers or partial restriction at the pump intake screen,
reducing hydraulic work.
Question 5
During a well drilling operation, a contractor encounters an unexpected underground storage
tank that appears to be leaking. Ethically and legally, what should the contractor do first?
VERIFIED AND WELL DETAILED ANSWERS | PLUS RATIONALES | GUARANTEED
PASS | LATEST EXAM UPDATE
CORE DOMAINS *
• Hydrogeology and Fluid Mechanics
• Well Drilling Methods and Design
• Water System Dynamics and Hydraulics
• Water Quality, Testing, and Treatment
• Pump Selection, Installation, and Maintenance
• Safety Standards and Hazardous Materials
• Regulatory Compliance and Environmental Law
• Professional Ethics and Business Practices
INTRODUCTION *
The NGWA Water Systems Certification Exam is a comprehensive assessment
designed to evaluate the critical knowledge, technical skills, and professional
competency required of water well system professionals. This exam ensures that
practitioners possess a thorough understanding of hydrogeology, well construction,
system design, and regulatory compliance. Featuring a mix of multiple-choice and
complex, scenario-based questions, the assessment places a heavy emphasis on
real-world application, diagnostics, and ethical decision-making. Candidates are tested
on their ability to analyze hydraulic data, troubleshoot system failures, and implement
, safe, efficient, and environmentally sound water delivery solutions under diverse field
conditions.
Question 1
Which type of aquifer is bounded above and below by impermeable layers, causing the
water within it to be under hydrostatic pressure?
A. Unconfined aquifer
B. Perched aquifer
C. Confined aquifer
D. Water table aquifer
🟢 C. Confined aquifer
🔴 Explanation: A confined aquifer is trapped between two impermeable layers (aquicludes
or aquitards), putting the water under pressure. If a well penetrates this layer, water rises
above the top of the aquifer.
Question 2
When sizing a residential submersible pump, what are the two primary parameters that must
be determined?
,A. Casing diameter and well depth
B. Total Dynamic Head (TDH) and Flow Rate (GPM)
C. Static water level and motor horsepower
D. Friction loss and voltage drop
🟢 B. Total Dynamic Head (TDH) and Flow Rate (GPM)
🔴 Explanation: Total Dynamic Head (TDH) and the required flow rate in Gallons Per Minute
(GPM) are the fundamental metrics needed to select a pump curve that operates efficiently.
Question 3
According to EPA National Primary Drinking Water Regulations, what is the Maximum
Contaminant Level (MCL) for Total Coliform bacteria in public water systems?
A. Less than 5% of monthly samples can be positive
B. Zero positive samples allowed annually
C. 10 parts per million
D. 1 count per 100 milliliters
🟢 A. Less than 5% of monthly samples can be positive
, 🔴 Explanation: For public water systems that collect 40 or more samples per month, no
more than 5.0% of the samples may be positive for total coliform. For systems collecting
fewer than 40 samples, no more than one sample can be positive.
Question 4
A multi-stage centrifugal submersible pump is experiencing a drop in capacity and pressure,
but the motor is drawing normal running amps. What is the most likely cause?
A. Motor running in reverse
B. Blown fuse on one line
C. Worn impellers or blocked intake
D. Voltage drop in the drop cable
🟢 C. Worn impellers or blocked intake
🔴 Explanation: A drop in both capacity and pressure with normal current draw typically
points to mechanical wear of the impellers or partial restriction at the pump intake screen,
reducing hydraulic work.
Question 5
During a well drilling operation, a contractor encounters an unexpected underground storage
tank that appears to be leaking. Ethically and legally, what should the contractor do first?
