1|Page
Arizona Water Treatment Operator Certification Exam
– Grade 1||VERIFIED QUESTIONS AND VERIFIED
ANSWERS WITH RATIONALES.pdf1
A public water system serves a population greater than or
equal to:
A. 25
B. 50
C. 100 - Answer-A. 25
What type of contaminant is iron?
A. Primary Inorganic
B. Primary Organic
C. Secondary - Answer-C. Secondary
The MCL for Total Trihalomethanes is:
A. 0.010 mg/L
B. 0.080 mg/L
C. 0.200 mg/L - Answer-B. 0.080 mg/L
,2|Page
The SDWA compliance cycle for the standardized
monitoring rule consists of 3:
A. Years
B. Compliance periods
C. Quarters
D. Months - Answer-B. Compliance Periods
A 3-log removal is a __________ % reduction.
A. 90%
B. 99%
C. 99.9% - Answer-C. 99.9%
Why is sodium thiosulphate used in a microbiological
sample? - Answer-To dechlorinate
Microbiological samples must be tested within
__________ hours.
A. 12
B. 24
C. 30
D. 36 - Answer-B. 24
,3|Page
If a systems take one microbiological sample a month,
how many repeat samples must be taken when positive
result are reported?
A. 2
B. 3
C. 4
D. 5 - Answer-C. 4
How many milliliters of sample are required for testing?
A. 50
B. 75
C. 100
D. 125 - Answer-C. 100
Which samples cannot have air bubbles in them? -
Answer-40 mls viles (organic samples)
Which chemicals are for preserving inorganic samples? -
Answer-Nitric Acid, Sulfuric Acid, Muriatic Acid, HCl
, 4|Page
What is a pH buffer used for? - Answer-Calibration
What would you be doing if you were reading a meniscus -
Answer-Volume Titration
What kind of test is the MPN method? - Answer-
Bacteriological (BACT)
What are the 2 indicators used in the alkalinity test? -
Answer-Phenolphthalein, and Methyl Green
What does the term "normality" of a chemical solution
mean? - Answer-It has to be standardized
Which of these chemicals will not raise the alkalinity of
water?
A. Calcium Carbonate
B. Sodium Hydroxide
C. Sodium Chloride
D. Calcium Oxide - Answer-C. Sodium Chloride
Arizona Water Treatment Operator Certification Exam
– Grade 1||VERIFIED QUESTIONS AND VERIFIED
ANSWERS WITH RATIONALES.pdf1
A public water system serves a population greater than or
equal to:
A. 25
B. 50
C. 100 - Answer-A. 25
What type of contaminant is iron?
A. Primary Inorganic
B. Primary Organic
C. Secondary - Answer-C. Secondary
The MCL for Total Trihalomethanes is:
A. 0.010 mg/L
B. 0.080 mg/L
C. 0.200 mg/L - Answer-B. 0.080 mg/L
,2|Page
The SDWA compliance cycle for the standardized
monitoring rule consists of 3:
A. Years
B. Compliance periods
C. Quarters
D. Months - Answer-B. Compliance Periods
A 3-log removal is a __________ % reduction.
A. 90%
B. 99%
C. 99.9% - Answer-C. 99.9%
Why is sodium thiosulphate used in a microbiological
sample? - Answer-To dechlorinate
Microbiological samples must be tested within
__________ hours.
A. 12
B. 24
C. 30
D. 36 - Answer-B. 24
,3|Page
If a systems take one microbiological sample a month,
how many repeat samples must be taken when positive
result are reported?
A. 2
B. 3
C. 4
D. 5 - Answer-C. 4
How many milliliters of sample are required for testing?
A. 50
B. 75
C. 100
D. 125 - Answer-C. 100
Which samples cannot have air bubbles in them? -
Answer-40 mls viles (organic samples)
Which chemicals are for preserving inorganic samples? -
Answer-Nitric Acid, Sulfuric Acid, Muriatic Acid, HCl
, 4|Page
What is a pH buffer used for? - Answer-Calibration
What would you be doing if you were reading a meniscus -
Answer-Volume Titration
What kind of test is the MPN method? - Answer-
Bacteriological (BACT)
What are the 2 indicators used in the alkalinity test? -
Answer-Phenolphthalein, and Methyl Green
What does the term "normality" of a chemical solution
mean? - Answer-It has to be standardized
Which of these chemicals will not raise the alkalinity of
water?
A. Calcium Carbonate
B. Sodium Hydroxide
C. Sodium Chloride
D. Calcium Oxide - Answer-C. Sodium Chloride
