GWWI WATER DISTRIBUTION TEST PRACTICE QUESTIONS WITH
CORRECT ANSWERS 2025/2026
Percentage of sodium hypochlorite. - CORRECT ANSWER -5.25%
Test pressure should be how many times greater than the highest point along test section? -
CORRECT ANSWER -1.5 times
Minimum GPM through bypass. - CORRECT ANSWER -3 GPM
Calcium hypochlorite - CORRECT ANSWER -CaOCl2
HTH
65% strength for disinfection
Sodium hypochlorite - CORRECT ANSWER -NaClO
Commonly known as bleach
What does a drive coupling transfer? - CORRECT ANSWER -Energy
How long is the break when replacing packing in the stuffing box? - CORRECT ANSWER -2 hours
How much chlorine can you get out of 150
pound cylinder? - CORRECT ANSWER -42lbs/Day @ 70 degrees Fahrenheit
How much chlorine can you get out of a 1000 lb tank - CORRECT ANSWER -400 lbs/day @ 70
degrees Fahrenheit
,Bedding up to 50% of pipe diameter increases supporting strength by. - CORRECT ANSWER -36%
How far from edge of a trench should you keep all materials? - CORRECT ANSWER -2 feet
PI - CORRECT ANSWER -Point of intersection
BC or PC - CORRECT ANSWER -Beginning of a curve
Point of curve
Name of liquid chlorine solution commonly used for disinfection. - CORRECT ANSWER -Sodium
hypochlorite
What year was the safe drinking water act passed? - CORRECT ANSWER -1974
pH (0-14) scale - CORRECT ANSWER -Below 7 Acidic
7 neutral
Above 7 Basic
SMCL - CORRECT ANSWER -Secondary maximum contaminant level
Manganese will not cause. - CORRECT ANSWER -Red water
Sub-atmospheric pressure (vacuum or suction) in the water system that pulls water the wrong
way. - CORRECT ANSWER -Backsiphonage
Diaphragm pump is best used for. - CORRECT ANSWER -Continuous feed
, Measurement of breakaway flanges above grade for fire hydrants. - CORRECT ANSWER -2 - 6
inches
MCL - CORRECT ANSWER -Maximum contaminate level
C x T = - CORRECT ANSWER -Chlorine concentration + contact time
Fusible plug melts at. - CORRECT ANSWER -158 - 165 degrees Fahrenheit
The line which connects all the piezometric surfaces along a pipeline. - CORRECT ANSWER -
Hydraulic grade line
Standard shape on the operating nut on a dry barrel hydrant. - CORRECT ANSWER -Pentagon
How much can pressure vary during hydrostatic test? - CORRECT ANSWER -+5 PSI
How long does a hydrostatic test last? - CORRECT ANSWER -2 hours
Hydrostatic test - CORRECT ANSWER -Testing method that uses water under pressure to check
the integrity of pressure vessels.
True or false
All energy devices motors/valves must be shut down, locked out and tagged. - CORRECT
ANSWER -True
In a confined space, how often must air be tested for explosive and hazardous gases? - CORRECT
ANSWER -Every 30 minutes
CORRECT ANSWERS 2025/2026
Percentage of sodium hypochlorite. - CORRECT ANSWER -5.25%
Test pressure should be how many times greater than the highest point along test section? -
CORRECT ANSWER -1.5 times
Minimum GPM through bypass. - CORRECT ANSWER -3 GPM
Calcium hypochlorite - CORRECT ANSWER -CaOCl2
HTH
65% strength for disinfection
Sodium hypochlorite - CORRECT ANSWER -NaClO
Commonly known as bleach
What does a drive coupling transfer? - CORRECT ANSWER -Energy
How long is the break when replacing packing in the stuffing box? - CORRECT ANSWER -2 hours
How much chlorine can you get out of 150
pound cylinder? - CORRECT ANSWER -42lbs/Day @ 70 degrees Fahrenheit
How much chlorine can you get out of a 1000 lb tank - CORRECT ANSWER -400 lbs/day @ 70
degrees Fahrenheit
,Bedding up to 50% of pipe diameter increases supporting strength by. - CORRECT ANSWER -36%
How far from edge of a trench should you keep all materials? - CORRECT ANSWER -2 feet
PI - CORRECT ANSWER -Point of intersection
BC or PC - CORRECT ANSWER -Beginning of a curve
Point of curve
Name of liquid chlorine solution commonly used for disinfection. - CORRECT ANSWER -Sodium
hypochlorite
What year was the safe drinking water act passed? - CORRECT ANSWER -1974
pH (0-14) scale - CORRECT ANSWER -Below 7 Acidic
7 neutral
Above 7 Basic
SMCL - CORRECT ANSWER -Secondary maximum contaminant level
Manganese will not cause. - CORRECT ANSWER -Red water
Sub-atmospheric pressure (vacuum or suction) in the water system that pulls water the wrong
way. - CORRECT ANSWER -Backsiphonage
Diaphragm pump is best used for. - CORRECT ANSWER -Continuous feed
, Measurement of breakaway flanges above grade for fire hydrants. - CORRECT ANSWER -2 - 6
inches
MCL - CORRECT ANSWER -Maximum contaminate level
C x T = - CORRECT ANSWER -Chlorine concentration + contact time
Fusible plug melts at. - CORRECT ANSWER -158 - 165 degrees Fahrenheit
The line which connects all the piezometric surfaces along a pipeline. - CORRECT ANSWER -
Hydraulic grade line
Standard shape on the operating nut on a dry barrel hydrant. - CORRECT ANSWER -Pentagon
How much can pressure vary during hydrostatic test? - CORRECT ANSWER -+5 PSI
How long does a hydrostatic test last? - CORRECT ANSWER -2 hours
Hydrostatic test - CORRECT ANSWER -Testing method that uses water under pressure to check
the integrity of pressure vessels.
True or false
All energy devices motors/valves must be shut down, locked out and tagged. - CORRECT
ANSWER -True
In a confined space, how often must air be tested for explosive and hazardous gases? - CORRECT
ANSWER -Every 30 minutes
