Class C Drinking Water Practice Test
With Full Set Correct Answers| Pass!!
Why does filtration typically follow PAC addition in a water treatment plant?
A. Filters are necessary to provide the contact time for PAC to be effective.
B. PAC creates turbidity which must be removed before distribution.
C. Chlorine in the filters will deactivate the PAC.
D. The PAC must be applied as "cap" on the filter media for it to be effective.
- Ans--C. Chlorine in the filters will deactivate the PAC.
Aluminum, zinc, and magnesium are often used as anodes to prevent
corrosion to other metals. Where does aluminum, zinc, and magnesium
place in the galvanic series? - Ans--as the most active metals
In the corrosion Cell, the anode is the... - Ans--positive pole
metallic corrosion in potable water is always the result of - Ans--an
electrochemical reaction
if the result of the Langelier index test on water in a distribution system is
positive, then which of the following statements is correct...
1. the water in the distribution system is corrosive
2. the water in the distribution system is scale forming
3. the source water entering the conventional filter plant is aggressive
4. the well water will need ion exchange softening - Ans--the water in the
distribution system is scale forming
special steel specimens called coupons are inserted into a water main.
After several months, the specimens are removed from the main. All
coupons have lost weight over the period of time. What does this indicate? -
Ans--the water is corrosive
The location where metal is lost in a corrosion cell is called the
,A. anode
B. cathode
C. electrolyte
D. dielectric - Ans--A. anode
The operator of the water system is experiencing an increased amount of
water leaks in the system, and lab results for lead and copper show an
increase in both over time. The operator suspects corrosion is taking place
in the system. Which lab tests listed will help confirm that corrosion is taking
place?
A. Dissolved oxygen, TDS, temperature
B. Temperature, pH, ammonia
C. Dissolved oxygen, alkalinity, temperature
D. Dissolved oxygen, pH, coupon analysis - Ans--D. Dissolved oxygen, pH,
coupon analysis
The reaction of dissolved oxygen with ferrous ions is reduced during which
condition?
A. High pH values
B. Low pH values
C. Low flow velocity
D. Low water temperatures - Ans--B. Low pH values
What is the term for an insulator used to prevent corrosion by separating
two dissimilar metals?
A. dielectric
B. sacrificial cathode
C. sacrificial anode
D. inhibitor - Ans--A. dielectric
Which chemical can be used to mask red water problems by bonding with
iron, but could increase corrosion by reducing calcium carbonate scale
forming ability?
A. Sodium hypochlorite
, B. Hydrofluosalicic acid
C. Sodium hexametaphosphate
D. Zinc orthophosphate - Ans--C. Sodium hexametaphosphate
Which of the elements or compounds listed below is considered to be the
most corrosive component of water chemistry?
A. Lead
B. Copper
C. Carbon Monoxide
D. Dissolved Oxygen - Ans--D. Dissolved Oxygen
A dosage of three parts of chlorine to one part ammonia will form what
compound?
A. monochloramine
B. dichloramine
C. trichloramine
D. nitrogen trichloride - Ans--A. monochloramine
According to FAC Chapter 62-550, Table 3, Maximum Contaminant Levels
for disinfection byproducts, what is the MCL for total trihalomethane
(TTHM)?
A. 0.006 mg/L
B. 0.080 mg/L
C. 0.1 mg/L
D. 10 mg/L - Ans--B. 0.080 mg/L
CT Values are calculated using what two pieces of data?
A. Chlorine demand and contact time
B. Chlorine concentration after contact time and the total detention time
C. Concentration of chlorine and temperature
D. Chlorine demand and temperature - Ans--B. Chlorine concentration
after contact time and the total detention time
With Full Set Correct Answers| Pass!!
Why does filtration typically follow PAC addition in a water treatment plant?
A. Filters are necessary to provide the contact time for PAC to be effective.
B. PAC creates turbidity which must be removed before distribution.
C. Chlorine in the filters will deactivate the PAC.
D. The PAC must be applied as "cap" on the filter media for it to be effective.
- Ans--C. Chlorine in the filters will deactivate the PAC.
Aluminum, zinc, and magnesium are often used as anodes to prevent
corrosion to other metals. Where does aluminum, zinc, and magnesium
place in the galvanic series? - Ans--as the most active metals
In the corrosion Cell, the anode is the... - Ans--positive pole
metallic corrosion in potable water is always the result of - Ans--an
electrochemical reaction
if the result of the Langelier index test on water in a distribution system is
positive, then which of the following statements is correct...
1. the water in the distribution system is corrosive
2. the water in the distribution system is scale forming
3. the source water entering the conventional filter plant is aggressive
4. the well water will need ion exchange softening - Ans--the water in the
distribution system is scale forming
special steel specimens called coupons are inserted into a water main.
After several months, the specimens are removed from the main. All
coupons have lost weight over the period of time. What does this indicate? -
Ans--the water is corrosive
The location where metal is lost in a corrosion cell is called the
,A. anode
B. cathode
C. electrolyte
D. dielectric - Ans--A. anode
The operator of the water system is experiencing an increased amount of
water leaks in the system, and lab results for lead and copper show an
increase in both over time. The operator suspects corrosion is taking place
in the system. Which lab tests listed will help confirm that corrosion is taking
place?
A. Dissolved oxygen, TDS, temperature
B. Temperature, pH, ammonia
C. Dissolved oxygen, alkalinity, temperature
D. Dissolved oxygen, pH, coupon analysis - Ans--D. Dissolved oxygen, pH,
coupon analysis
The reaction of dissolved oxygen with ferrous ions is reduced during which
condition?
A. High pH values
B. Low pH values
C. Low flow velocity
D. Low water temperatures - Ans--B. Low pH values
What is the term for an insulator used to prevent corrosion by separating
two dissimilar metals?
A. dielectric
B. sacrificial cathode
C. sacrificial anode
D. inhibitor - Ans--A. dielectric
Which chemical can be used to mask red water problems by bonding with
iron, but could increase corrosion by reducing calcium carbonate scale
forming ability?
A. Sodium hypochlorite
, B. Hydrofluosalicic acid
C. Sodium hexametaphosphate
D. Zinc orthophosphate - Ans--C. Sodium hexametaphosphate
Which of the elements or compounds listed below is considered to be the
most corrosive component of water chemistry?
A. Lead
B. Copper
C. Carbon Monoxide
D. Dissolved Oxygen - Ans--D. Dissolved Oxygen
A dosage of three parts of chlorine to one part ammonia will form what
compound?
A. monochloramine
B. dichloramine
C. trichloramine
D. nitrogen trichloride - Ans--A. monochloramine
According to FAC Chapter 62-550, Table 3, Maximum Contaminant Levels
for disinfection byproducts, what is the MCL for total trihalomethane
(TTHM)?
A. 0.006 mg/L
B. 0.080 mg/L
C. 0.1 mg/L
D. 10 mg/L - Ans--B. 0.080 mg/L
CT Values are calculated using what two pieces of data?
A. Chlorine demand and contact time
B. Chlorine concentration after contact time and the total detention time
C. Concentration of chlorine and temperature
D. Chlorine demand and temperature - Ans--B. Chlorine concentration
after contact time and the total detention time
