Water distribution D2 test Bank 160 Questions and Correct Detailed
Answers \Verified 100% Already Graded A+\Latest update 2026
What is a time composite sample?
ANSWERS: Equal volumes at regular intervals
What is a flow proportional composite sample?
ANSWERS: Adjusting the sample size proportional to the flow
How do you select a sample point?
ANSWERS: As close to the main as possible
True or false: It is required for samples to be taken from groundwater under the
direct influence of surface water.
ANSWERS: true
What are Sanitary Surveys?
ANSWERS: On site annual inspection of a water system's facilities and operation.
,What are some the requirements that the State establishes to ensure proper
water system operation?
ANSWERS: Operator Certification, sanitary surveys, enforcement
What are the 3 main areas of concern to distribution operators?
ANSWERS: microbiological safety, disinfection by products, lead
Total coliform rule
ANSWERS: to require surveillance of total coliform bacteria
When you have a positive sample for coliform you need to take another test
within
___hrs?
ANSWERS: 24
What are the different disinfectants?
ANSWERS: physical and chemical
What is hardness?
ANSWERS: the measure of the concentration of calcium and magnesium in water
What type of iron bacteria causes red water, taste and odors, clogged pipes and
pump failure?
ANSWERS: Gallionella
, What is the secondary drinking water standards suggest the limit of iron be in
water?
ANSWERS: 0.5mg/L
Does very hard or very soft water cause scaling to form in plumbing fixtures
and cooking water?
ANSWERS: hard water
What must the turbidity be equal to or less than in measurements taken each
month?
ANSWERS: 0.5 ntu
What chemical is not harmful to humans but stains washed clothes and plumbing
fixtures black?
ANSWERS: manganese
What is necessary to prevent backsiphonage and the entry of contaminants?
ANSWERS: continuous positive pressure
What are the 4 water quality safeguards?
ANSWERS: continuous positive pressure, maintenance of chlorine residual,
cross connection control, frequent testing
Answers \Verified 100% Already Graded A+\Latest update 2026
What is a time composite sample?
ANSWERS: Equal volumes at regular intervals
What is a flow proportional composite sample?
ANSWERS: Adjusting the sample size proportional to the flow
How do you select a sample point?
ANSWERS: As close to the main as possible
True or false: It is required for samples to be taken from groundwater under the
direct influence of surface water.
ANSWERS: true
What are Sanitary Surveys?
ANSWERS: On site annual inspection of a water system's facilities and operation.
,What are some the requirements that the State establishes to ensure proper
water system operation?
ANSWERS: Operator Certification, sanitary surveys, enforcement
What are the 3 main areas of concern to distribution operators?
ANSWERS: microbiological safety, disinfection by products, lead
Total coliform rule
ANSWERS: to require surveillance of total coliform bacteria
When you have a positive sample for coliform you need to take another test
within
___hrs?
ANSWERS: 24
What are the different disinfectants?
ANSWERS: physical and chemical
What is hardness?
ANSWERS: the measure of the concentration of calcium and magnesium in water
What type of iron bacteria causes red water, taste and odors, clogged pipes and
pump failure?
ANSWERS: Gallionella
, What is the secondary drinking water standards suggest the limit of iron be in
water?
ANSWERS: 0.5mg/L
Does very hard or very soft water cause scaling to form in plumbing fixtures
and cooking water?
ANSWERS: hard water
What must the turbidity be equal to or less than in measurements taken each
month?
ANSWERS: 0.5 ntu
What chemical is not harmful to humans but stains washed clothes and plumbing
fixtures black?
ANSWERS: manganese
What is necessary to prevent backsiphonage and the entry of contaminants?
ANSWERS: continuous positive pressure
What are the 4 water quality safeguards?
ANSWERS: continuous positive pressure, maintenance of chlorine residual,
cross connection control, frequent testing
