Class D Water Operator: Questions With Complete
Answers (Rated A+)
What are some physical characteristics of water? Right Ans - Temperature,
turbidity, color, taste, odor
What are some chemical characteristics of water? Right Ans - Hardness,
pH, solids, and gases
What is turbidity? Right Ans - the amount of suspended matter, such as
clay, silt, organic matter, and microorganisms in water
T/F Water is never found pure in nature. Right Ans - True
Is turbidity more of a problem in groundwater or surface water? Right Ans
- 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. Right Ans - 0.3
1
T/F True color is dissolved in water (in solution) and cannot be removed by
filtering. Right Ans - True. Tea in water is an example of true color.
Suspended color is called _______ color. Right Ans - apparent
Color above ______ units is objectionable in a public water supply. Right Ans
- 15 units
A scale called the ________ measures odor. Right Ans - Threshold Odor
Number (TON)
Odor greater than a scale of _______ is undesirable. Right Ans - 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. Right Ans - algae
, Chemical characteristics of water generally cannot be detected by sight, smell,
or taste and must be determined by __________. Right Ans - laboratory
analysis
Chemical laboratory analysis must be sampled _______ per year for surface
water and normally _______ for groundwater. Right Ans - once/year for
surface water
once every three years for groundwater
Water weighs ______ lbs/gal. Right Ans - 8.34 lbs/gal
T/F
For water, 1 mg/L is equal to 1 part per million (ppm) by weight. Right Ans
- True
Which two minerals mainly cause hardness in water? Right Ans - Calcium
and magnesium
Is hardness more of a problem in groundwater or surface water? Right Ans
- Groundwater
Water is considered hard when it exceeds _______. Right Ans - 100 mg/L of
calcium carbonate
The pH scale ranges from _____ to _____. Right Ans - 0 to 14
On the pH scale:
0 to <7 is ______.
7 is _______.
>7 to 14 is ______. Right Ans - Acidic
Neutral
Basic or alkaline
Sulfuric, hydrochloric, and nitric acids can be used to ______ pH.
Caustic, lime, or soda ash can be used to ______ pH. Right Ans - Lower
Raise
Suspended solids can be removed by ________. Right Ans - Filtration
Answers (Rated A+)
What are some physical characteristics of water? Right Ans - Temperature,
turbidity, color, taste, odor
What are some chemical characteristics of water? Right Ans - Hardness,
pH, solids, and gases
What is turbidity? Right Ans - the amount of suspended matter, such as
clay, silt, organic matter, and microorganisms in water
T/F Water is never found pure in nature. Right Ans - True
Is turbidity more of a problem in groundwater or surface water? Right Ans
- 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. Right Ans - 0.3
1
T/F True color is dissolved in water (in solution) and cannot be removed by
filtering. Right Ans - True. Tea in water is an example of true color.
Suspended color is called _______ color. Right Ans - apparent
Color above ______ units is objectionable in a public water supply. Right Ans
- 15 units
A scale called the ________ measures odor. Right Ans - Threshold Odor
Number (TON)
Odor greater than a scale of _______ is undesirable. Right Ans - 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. Right Ans - algae
, Chemical characteristics of water generally cannot be detected by sight, smell,
or taste and must be determined by __________. Right Ans - laboratory
analysis
Chemical laboratory analysis must be sampled _______ per year for surface
water and normally _______ for groundwater. Right Ans - once/year for
surface water
once every three years for groundwater
Water weighs ______ lbs/gal. Right Ans - 8.34 lbs/gal
T/F
For water, 1 mg/L is equal to 1 part per million (ppm) by weight. Right Ans
- True
Which two minerals mainly cause hardness in water? Right Ans - Calcium
and magnesium
Is hardness more of a problem in groundwater or surface water? Right Ans
- Groundwater
Water is considered hard when it exceeds _______. Right Ans - 100 mg/L of
calcium carbonate
The pH scale ranges from _____ to _____. Right Ans - 0 to 14
On the pH scale:
0 to <7 is ______.
7 is _______.
>7 to 14 is ______. Right Ans - Acidic
Neutral
Basic or alkaline
Sulfuric, hydrochloric, and nitric acids can be used to ______ pH.
Caustic, lime, or soda ash can be used to ______ pH. Right Ans - Lower
Raise
Suspended solids can be removed by ________. Right Ans - Filtration
