Class D Water Operator Exam (100 out of 100)
Questions and Answers (Already GRADED A)
COMPLETE SOLUTIONS
What are some physical characteristics of water?
Temperature, turbidity, color, taste, odor
What are some chemical characteristics of water?
Hardness, pH, solids, and gases
What is turbidity?
the amount of suspended matter, such as clay, silt, organic matter, and microorganisms in water
T/F Water is never found pure in nature.
True
Is turbidity more of a problem in groundwater or surface water?
Surface water
A system's filtered water must be _______ Nephelometric Turbidity Units (NTU) or less in at least 95% of
the measurements taken each month, and no sample can exceed _____ NTU.
0.3
1
,T/F True color is dissolved in water (in solution) and cannot be removed by filtering.
True. Tea in water is an example of true color.
Suspended color is called _______ color.
apparent
Color above ______ units is objectionable in a public water supply.
15 units
A scale called the ________ measures odor.
Threshold Odor Number (TON)
Odor greater than a scale of _______ is undesirable.
3
Taste and odors in water result from _______, bacteria, decaying organic matter, gases, and chemicals
such as manganese, zinc, copper, iron, magnesium, sodium, and potassium.
algae
Chemical characteristics of water generally cannot be detected by sight, smell, or taste and must be
determined by __________.
, laboratory analysis
Chemical laboratory analysis must be sampled _______ per year for surface water and normally
_______ for groundwater.
once/year for surface water
once every three years for groundwater
Water weighs ______ lbs/gal.
8.34 lbs/gal
T/F
For water, 1 mg/L is equal to 1 part per million (ppm) by weight.
True
Which two minerals mainly cause hardness in water?
Calcium and magnesium
Is hardness more of a problem in groundwater or surface water?
Groundwater
Water is considered hard when it exceeds _______.
100 mg/L of calcium carbonate
Questions and Answers (Already GRADED A)
COMPLETE SOLUTIONS
What are some physical characteristics of water?
Temperature, turbidity, color, taste, odor
What are some chemical characteristics of water?
Hardness, pH, solids, and gases
What is turbidity?
the amount of suspended matter, such as clay, silt, organic matter, and microorganisms in water
T/F Water is never found pure in nature.
True
Is turbidity more of a problem in groundwater or surface water?
Surface water
A system's filtered water must be _______ Nephelometric Turbidity Units (NTU) or less in at least 95% of
the measurements taken each month, and no sample can exceed _____ NTU.
0.3
1
,T/F True color is dissolved in water (in solution) and cannot be removed by filtering.
True. Tea in water is an example of true color.
Suspended color is called _______ color.
apparent
Color above ______ units is objectionable in a public water supply.
15 units
A scale called the ________ measures odor.
Threshold Odor Number (TON)
Odor greater than a scale of _______ is undesirable.
3
Taste and odors in water result from _______, bacteria, decaying organic matter, gases, and chemicals
such as manganese, zinc, copper, iron, magnesium, sodium, and potassium.
algae
Chemical characteristics of water generally cannot be detected by sight, smell, or taste and must be
determined by __________.
, laboratory analysis
Chemical laboratory analysis must be sampled _______ per year for surface water and normally
_______ for groundwater.
once/year for surface water
once every three years for groundwater
Water weighs ______ lbs/gal.
8.34 lbs/gal
T/F
For water, 1 mg/L is equal to 1 part per million (ppm) by weight.
True
Which two minerals mainly cause hardness in water?
Calcium and magnesium
Is hardness more of a problem in groundwater or surface water?
Groundwater
Water is considered hard when it exceeds _______.
100 mg/L of calcium carbonate
