Water Treatment Plant Operator ACTUAL
UPDATED Exam Questions and
CORRECT Answers
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? - CORRECT
ANSWER As the most active metals
In the corrosion cell, the anode is the - CORRECT ANSWER Positive pole
Metallic corrosion in potable water is always a result of? - CORRECT ANSWER 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? - CORRECT ANSWER The water in the
distribution system is scale forming
Special steel specimens are called coupons inserted into a water main, after several months, the
specimens are removed from the main. All the coupons have lost weight over the period of time.
What does this indicate? - CORRECT ANSWER The water is corrosive
The location where metal is lost in a corrosion cell is called the? - CORRECT
ANSWER Anode
The operator suspects corrosion is taking place in the system. Which lab test will help confirm
that corrosion is taking place? - CORRECT ANSWER Dissolved oxygen, PH, coupon
analysis
The reaction of dissolved oxygen with ferrous ions is reduced during which condition? -
CORRECT ANSWER Low PH values
, What is the term for an insulator used to prevent corrosion by separating two dissimilar metals -
CORRECT ANSWER Dielectric
Which chemical can be use to mask red water problems by bonding with iron, but could increase
corrosion by reducing calcium carbonate scale forming ability? - CORRECT
ANSWER Sodium Hexametaphophate
Which of the elements or compounds is considered to be the most corrosive component of water
chemistry? - CORRECT ANSWER Dissolved oxygen
A dosage of three parts chlorine to one part ammonia will form what compound? - CORRECT
ANSWER Monochloramine
MCL for Trihalomethane (TTHM)? - CORRECT ANSWER 0.08 mg/L
MCL for Lead - CORRECT ANSWER 0.015 mg/L
MCL for Copper - CORRECT ANSWER 1.3 mg/L
MCL for Total Nitrate - CORRECT ANSWER 10 mg/L
MCL for fluoride - CORRECT ANSWER 4.0 mg/L
MCL for Maximum turbidity - CORRECT ANSWER 5.0 NTU
MCL for Haloacetic Acids (HAA5) - CORRECT ANSWER 0.060 mg/L
Secondary MCLs affect what type of aesthetic quality? - CORRECT ANSWER - Color
- Iron
UPDATED Exam Questions and
CORRECT Answers
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? - CORRECT
ANSWER As the most active metals
In the corrosion cell, the anode is the - CORRECT ANSWER Positive pole
Metallic corrosion in potable water is always a result of? - CORRECT ANSWER 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? - CORRECT ANSWER The water in the
distribution system is scale forming
Special steel specimens are called coupons inserted into a water main, after several months, the
specimens are removed from the main. All the coupons have lost weight over the period of time.
What does this indicate? - CORRECT ANSWER The water is corrosive
The location where metal is lost in a corrosion cell is called the? - CORRECT
ANSWER Anode
The operator suspects corrosion is taking place in the system. Which lab test will help confirm
that corrosion is taking place? - CORRECT ANSWER Dissolved oxygen, PH, coupon
analysis
The reaction of dissolved oxygen with ferrous ions is reduced during which condition? -
CORRECT ANSWER Low PH values
, What is the term for an insulator used to prevent corrosion by separating two dissimilar metals -
CORRECT ANSWER Dielectric
Which chemical can be use to mask red water problems by bonding with iron, but could increase
corrosion by reducing calcium carbonate scale forming ability? - CORRECT
ANSWER Sodium Hexametaphophate
Which of the elements or compounds is considered to be the most corrosive component of water
chemistry? - CORRECT ANSWER Dissolved oxygen
A dosage of three parts chlorine to one part ammonia will form what compound? - CORRECT
ANSWER Monochloramine
MCL for Trihalomethane (TTHM)? - CORRECT ANSWER 0.08 mg/L
MCL for Lead - CORRECT ANSWER 0.015 mg/L
MCL for Copper - CORRECT ANSWER 1.3 mg/L
MCL for Total Nitrate - CORRECT ANSWER 10 mg/L
MCL for fluoride - CORRECT ANSWER 4.0 mg/L
MCL for Maximum turbidity - CORRECT ANSWER 5.0 NTU
MCL for Haloacetic Acids (HAA5) - CORRECT ANSWER 0.060 mg/L
Secondary MCLs affect what type of aesthetic quality? - CORRECT ANSWER - Color
- Iron
