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NEW MEXICO WATER OPERATOR CERTIFICATION EXAM NEWEST
2025/2026 ACTUAL EXAM WITH COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+| ||PROFESSOR VERIFIED||
What method would you use to concentrate and retrieve low
numbers of bacteria from a large quantity of water? - ANSWER-
Membrane filtration
A typical colony in the membrane filter method has what type of
characteristics? - ANSWER-Pink to dark red with green metallic
surface sheen
In the presumptive phase of the Most Probable Number test, how
long does it take for the coliforms to produce gas? - ANSWER-24
to 48 hours
Chemical analysis for synthetic organic compounds should not be
collected in containers made of? - ANSWER-Polypropylene
How much acid per 100 mL should be used to preserve a sample
for later hardness analyses? - ANSWER-0.5 mL
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Conductivity measurements can assist the laboratory analyst in? -
ANSWER-Determining the degree of mineralization of the water
Water that is to be analyzed for inorganic metals should be
filtered for ______ before ______. - ANSWER-Dissolved metals,
preserving
In routine water quality sampling, what is an early warning sign
that conditions are becoming more conducive to sulfate reducing
bacteria? - ANSWER-Dramatic decline in dissolved oxygen
What type of violation requires an all clear notification to the
public? - ANSWER-Tier I
How many coliform positive samples are allowed each month for
water systems that collect less than 40 samples per month? -
ANSWER-1
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If a water sample tests positive for coliforms, the system must
collect a set of repeat samples within? - ANSWER-24 hours
A public water system is defined as? - ANSWER-System that has
at least 15 service connections or serves 25 or more persons 60
or more days each year. 15:25:60
Where are the sampling points located for required sampling of
coliform bacteria in a community water system? - ANSWER-At the
customers' faucets
Water being served to the public for a population greater than
3,300 must not have a disinfectant residual entering the
distribution system below what? - ANSWER-0.2 mg/L for more
than 4 hours
What is the action level for copper? - ANSWER-1.3 mg/L
Where are the sampling points located for required sampling of
turbidity in a community water system? - ANSWER-Points where
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the water enters the distribution system, including all filter
effluents if a surface water treatment plant
Under the Surface Water Treatment Rule, disinfection residuals
must be collected at the same location in the distribution system
as? - ANSWER-Coliform samples
What is the Maximum Contaminant Level for haloacetic acids
(HAA5)? - ANSWER-0.060 mg/L
If a water system collects at least 40 samples per month for the
analyses of total coliforms, what percent of total coliform positive
samples are acceptable for the system to remain in compliance
with the maximum contaminant level for total coliforms? -
ANSWER-No more than 5%
What level of removal and/or inactivation of viruses are water
systems required to achieve between a point where the raw water
is not subject to recontamination by surface water runoff and a
point downstream before or at the first customer? - ANSWER-4
log removal
NEW MEXICO WATER OPERATOR CERTIFICATION EXAM NEWEST
2025/2026 ACTUAL EXAM WITH COMPLETE QUESTIONS AND
CORRECT DETAILED ANSWERS (100% VERIFIED ANSWERS)
|ALREADY GRADED A+| ||PROFESSOR VERIFIED||
What method would you use to concentrate and retrieve low
numbers of bacteria from a large quantity of water? - ANSWER-
Membrane filtration
A typical colony in the membrane filter method has what type of
characteristics? - ANSWER-Pink to dark red with green metallic
surface sheen
In the presumptive phase of the Most Probable Number test, how
long does it take for the coliforms to produce gas? - ANSWER-24
to 48 hours
Chemical analysis for synthetic organic compounds should not be
collected in containers made of? - ANSWER-Polypropylene
How much acid per 100 mL should be used to preserve a sample
for later hardness analyses? - ANSWER-0.5 mL
,2|Page
Conductivity measurements can assist the laboratory analyst in? -
ANSWER-Determining the degree of mineralization of the water
Water that is to be analyzed for inorganic metals should be
filtered for ______ before ______. - ANSWER-Dissolved metals,
preserving
In routine water quality sampling, what is an early warning sign
that conditions are becoming more conducive to sulfate reducing
bacteria? - ANSWER-Dramatic decline in dissolved oxygen
What type of violation requires an all clear notification to the
public? - ANSWER-Tier I
How many coliform positive samples are allowed each month for
water systems that collect less than 40 samples per month? -
ANSWER-1
,3|Page
If a water sample tests positive for coliforms, the system must
collect a set of repeat samples within? - ANSWER-24 hours
A public water system is defined as? - ANSWER-System that has
at least 15 service connections or serves 25 or more persons 60
or more days each year. 15:25:60
Where are the sampling points located for required sampling of
coliform bacteria in a community water system? - ANSWER-At the
customers' faucets
Water being served to the public for a population greater than
3,300 must not have a disinfectant residual entering the
distribution system below what? - ANSWER-0.2 mg/L for more
than 4 hours
What is the action level for copper? - ANSWER-1.3 mg/L
Where are the sampling points located for required sampling of
turbidity in a community water system? - ANSWER-Points where
, 4|Page
the water enters the distribution system, including all filter
effluents if a surface water treatment plant
Under the Surface Water Treatment Rule, disinfection residuals
must be collected at the same location in the distribution system
as? - ANSWER-Coliform samples
What is the Maximum Contaminant Level for haloacetic acids
(HAA5)? - ANSWER-0.060 mg/L
If a water system collects at least 40 samples per month for the
analyses of total coliforms, what percent of total coliform positive
samples are acceptable for the system to remain in compliance
with the maximum contaminant level for total coliforms? -
ANSWER-No more than 5%
What level of removal and/or inactivation of viruses are water
systems required to achieve between a point where the raw water
is not subject to recontamination by surface water runoff and a
point downstream before or at the first customer? - ANSWER-4
log removal
