MINNESOTA CLASS D WATER EXAM QUESTIONS AND
ANSWERS
According to the Safe Drinking Water Act the basic definition of a public water supply system is any
water system that supplies water for human consumption that serves: - CORRECT ANSWER✅✅15
service connection or over 25 persons for over 60 days a year
What federal law regulates public water supplies? - CORRECT ANSWER✅✅Safe Drinking Water Act
What cause water to move through pores in soil and rocks ? - CORRECT ANSWER✅✅Gravity
What are disease producing bacteria called? - CORRECT ANSWER✅✅Pathogenic
A presence/absence coliform test utilizes - CORRECT ANSWER✅✅color change
What are two main causes of harness in water? - CORRECT ANSWER✅✅Calcium and magnesium
Which source of water has the greatest natural protection from bacterial contamination? - CORRECT
ANSWER✅✅deep well in gravel
Which of the following terms refers to excessive internal pressure which may be several times the
normal operating pressure and can seriously damage hydropnematic tanks, valves, and piping network. -
CORRECT ANSWER✅✅water hammer
What are the two most important safety concerns when entering a confined space? - CORRECT
ANSWER✅✅hazardous gases and oxygen deficiency
what piece of safety equipement must an operator wear when entering a confined space? - CORRECT
ANSWER✅✅Harness
Which document provides a profile of hazardous substances? - CORRECT ANSWER✅✅MSDS
, What safety measure must ab operator follow prior to working on electrical equipment? - CORRECT
ANSWER✅✅Lock out Tag out all electrical switches
what is the correct procedure for mixing acid an water - CORRECT ANSWER✅✅Acid is ADDED SLOWLY
to water
The major source of error when obtaining water quality information is improper - CORRECT
ANSWER✅✅Sampling
Polyphosphates should be fed at which point? - CORRECT ANSWER✅✅Before the addition of chlorine
After a new water main is installed and pressure is tested, it should be? - CORRECT ANSWER✅✅Filled
with a solution of 25 ppm to 50 ppm free chlorine for at least 24 hours before flushing
The minimum horizontal distance allowed between waterman and sanitary sewer is - CORRECT
ANSWER✅✅10 feet
The health department requires a minimum of how much free chlorine residual at distant points of the
ditribution system? - CORRECT ANSWER✅✅0.2 ppm
A PH reading of 2 means the water is: - CORRECT ANSWER✅✅Acidic
vent openings on reservoirs and clear wells should be: - CORRECT ANSWER✅✅Screened
How many pipe diameters should a meter be located in relationship to elbows or fittings? - CORRECT
ANSWER✅✅Three pipe diameters upstream, five pipe diameters downstream
chlorine leaks can be detected around a chlorine cylinder by the use of: - CORRECT
ANSWER✅✅Ammonia
ANSWERS
According to the Safe Drinking Water Act the basic definition of a public water supply system is any
water system that supplies water for human consumption that serves: - CORRECT ANSWER✅✅15
service connection or over 25 persons for over 60 days a year
What federal law regulates public water supplies? - CORRECT ANSWER✅✅Safe Drinking Water Act
What cause water to move through pores in soil and rocks ? - CORRECT ANSWER✅✅Gravity
What are disease producing bacteria called? - CORRECT ANSWER✅✅Pathogenic
A presence/absence coliform test utilizes - CORRECT ANSWER✅✅color change
What are two main causes of harness in water? - CORRECT ANSWER✅✅Calcium and magnesium
Which source of water has the greatest natural protection from bacterial contamination? - CORRECT
ANSWER✅✅deep well in gravel
Which of the following terms refers to excessive internal pressure which may be several times the
normal operating pressure and can seriously damage hydropnematic tanks, valves, and piping network. -
CORRECT ANSWER✅✅water hammer
What are the two most important safety concerns when entering a confined space? - CORRECT
ANSWER✅✅hazardous gases and oxygen deficiency
what piece of safety equipement must an operator wear when entering a confined space? - CORRECT
ANSWER✅✅Harness
Which document provides a profile of hazardous substances? - CORRECT ANSWER✅✅MSDS
, What safety measure must ab operator follow prior to working on electrical equipment? - CORRECT
ANSWER✅✅Lock out Tag out all electrical switches
what is the correct procedure for mixing acid an water - CORRECT ANSWER✅✅Acid is ADDED SLOWLY
to water
The major source of error when obtaining water quality information is improper - CORRECT
ANSWER✅✅Sampling
Polyphosphates should be fed at which point? - CORRECT ANSWER✅✅Before the addition of chlorine
After a new water main is installed and pressure is tested, it should be? - CORRECT ANSWER✅✅Filled
with a solution of 25 ppm to 50 ppm free chlorine for at least 24 hours before flushing
The minimum horizontal distance allowed between waterman and sanitary sewer is - CORRECT
ANSWER✅✅10 feet
The health department requires a minimum of how much free chlorine residual at distant points of the
ditribution system? - CORRECT ANSWER✅✅0.2 ppm
A PH reading of 2 means the water is: - CORRECT ANSWER✅✅Acidic
vent openings on reservoirs and clear wells should be: - CORRECT ANSWER✅✅Screened
How many pipe diameters should a meter be located in relationship to elbows or fittings? - CORRECT
ANSWER✅✅Three pipe diameters upstream, five pipe diameters downstream
chlorine leaks can be detected around a chlorine cylinder by the use of: - CORRECT
ANSWER✅✅Ammonia
