NM Water Level 4 exam #2
In a water plant that uses Coagulation, Sedimentation, and Filtration to treat the water. Which of the
following Chlorine application points would you have the lowest potential for generating THM's? -
(correct Answer) - In the finished water clear well
You recently heard an operator explaining that the under drains at the treatment plant were not
working. What treatment unit was the operator talking about? - (correct Answer) - Gravity Filter
Calculate the average detention time in a rectangular basin that is 90ft long by 40ft long of water depth
of 15ft . When the flow rate is 2 MGD ? - (correct Answer) - 2 Days
A new 10"in water main 2640 ft long is to be disinfected by applying 60 mg/l of Chlorine and allowing it
to stand for 24 hours. How many pounds of dry hypochlorite 65% chlorine will be needed? - (correct
Answer) - 8.3
When you are using a non exchanged softening such as Zeolite are known as? - (correct Answer) - Resins
What is the acceptable range of accuracy for small residential water meters? - (correct Answer) - 98.5%
to 101%
What does the term GAC refer to? - (correct Answer) - Granulated Active Carbon
What is indicated by the presence of fecal coliform or non coliform in a water sample? - (correct Answer)
- Contamination by animals or humans
How does organic matter increase the chlorine demand? - (correct Answer) - It combines with chlorine
to form less affective disinfectants
A water main break has lowered the water pressure in a section of the distribution system. What is one
possible result of this low pressure? - (correct Answer) - Contamination
An airline 200ft long is situated inside a well for determining the water level. Air is pumped into the
airline and the pressure gauge is stabilized at 36 psi. What is the water level in the well in feet ? - (correct
Answer) - 117 ft
Coliform bacteria must be tested for in accordance with the NMED drinking water regulations. What are
coliform bacteria? - (correct Answer) - Indicator Organisms
What affect will the addiction of chlorine gas have on the PH of the water ? - (correct Answer) - Lower
A near 1000ft long ___ inch diameter PVC pipeline is to be installed in a rocky area. A 24" in wide trench
was excavated to a depth of 4ft. How many cubic yards of bedding sand will be required to provide sand
encasement around the pipe for a total depth of 24" inches , assuming 12" inches of bedding is to be
replaced below the pipe? - (correct Answer) - 135 cubic yards
What is the amperometric nitration used to measure? - (correct Answer) - Chlorine residual
What is the purpose of an air relief valve on a pump? - (correct Answer) - Prevent Air Locking
, What is the MCL for Arsenic in mg/l? - (correct Answer) - 0.01 mg/l
Which of the following substances combines with Magnesium to give a laxative affect to the water ? -
(correct Answer) - Sulphates
You are the operator of a community water system located in anywhere New Mexico, anywhere is
required to collect a minimum of three compliance samples per month for a Total Coliform analysis. In
April one of Anywhere's water system samples reported as Total Coliform positive all repeat samples
collected, were reported Total Coliform negative. During May the anywhere water system reported a
routine sample as total Coliform positive. One of the May repeat. Samples reported as fecal chloroform
positive. Which of the following statements is correct? - (correct Answer) - This is an acute MCL violation
and public notification is required
In the situation described in the preceding questions, how many BACT compliance samples must be
collected by the Anywhere water system in June? - (correct Answer) - 5
An operator has discovered that a log has been cut from the hatch of a distribution system storage tank.
Until the incident is confirmed, treat this type of security breach as? - (correct Answer) - A potential
contamination threat
If an insufficient amount of chlorine is used for disinfection. The total chlorine residual may be made of
up combined chlorine residual causing a problem with taste and order. What causes this problem? -
(correct Answer) - Deconstruction of chlorine compounds
What does a reduction in specific capacity indicate? - (correct Answer) - Pumping cost increase
Which of the following is the least important in caring out a jar test? - (correct Answer) - Chloride
concentration
A water system serving 14,000 people has a service water treatment plant that includes it's conventional
treatment. Coagulation, sedimentation, filtration and chlorine disinfection under the capital, NM utility
operators certification regulations. What level of operator must be placed in charge of the system? -
(correct Answer) - Level lV (4)
What is the usual range for the detention time in a sedimentation basin? - (correct Answer) - 2-4 hours
According to the NM drinking water regulations, what is the maximum number of hours allowed
between a collection of a distribution system sampling and analysis for total coliforms? - (correct
Answer) - 30hrs
In the hench scale test, the proper Polyphosphate dose is the lowest dose that delays noticeable
discoloration for a period of? - (correct Answer) - 4 days
According to the US EPA safe drinking water act regulations. What is the basis for the number of monthly
samples you must collect for BAC-T test? - (correct Answer) - The population served
What is the primary purpose of the OSHA hazard communication standard? - (correct Answer) - To match
hazard warning, labels to all portable containers or written information that identifies hazards associated
with chemicals must be available and understandable to coworkers
In a water plant that uses Coagulation, Sedimentation, and Filtration to treat the water. Which of the
following Chlorine application points would you have the lowest potential for generating THM's? -
(correct Answer) - In the finished water clear well
You recently heard an operator explaining that the under drains at the treatment plant were not
working. What treatment unit was the operator talking about? - (correct Answer) - Gravity Filter
Calculate the average detention time in a rectangular basin that is 90ft long by 40ft long of water depth
of 15ft . When the flow rate is 2 MGD ? - (correct Answer) - 2 Days
A new 10"in water main 2640 ft long is to be disinfected by applying 60 mg/l of Chlorine and allowing it
to stand for 24 hours. How many pounds of dry hypochlorite 65% chlorine will be needed? - (correct
Answer) - 8.3
When you are using a non exchanged softening such as Zeolite are known as? - (correct Answer) - Resins
What is the acceptable range of accuracy for small residential water meters? - (correct Answer) - 98.5%
to 101%
What does the term GAC refer to? - (correct Answer) - Granulated Active Carbon
What is indicated by the presence of fecal coliform or non coliform in a water sample? - (correct Answer)
- Contamination by animals or humans
How does organic matter increase the chlorine demand? - (correct Answer) - It combines with chlorine
to form less affective disinfectants
A water main break has lowered the water pressure in a section of the distribution system. What is one
possible result of this low pressure? - (correct Answer) - Contamination
An airline 200ft long is situated inside a well for determining the water level. Air is pumped into the
airline and the pressure gauge is stabilized at 36 psi. What is the water level in the well in feet ? - (correct
Answer) - 117 ft
Coliform bacteria must be tested for in accordance with the NMED drinking water regulations. What are
coliform bacteria? - (correct Answer) - Indicator Organisms
What affect will the addiction of chlorine gas have on the PH of the water ? - (correct Answer) - Lower
A near 1000ft long ___ inch diameter PVC pipeline is to be installed in a rocky area. A 24" in wide trench
was excavated to a depth of 4ft. How many cubic yards of bedding sand will be required to provide sand
encasement around the pipe for a total depth of 24" inches , assuming 12" inches of bedding is to be
replaced below the pipe? - (correct Answer) - 135 cubic yards
What is the amperometric nitration used to measure? - (correct Answer) - Chlorine residual
What is the purpose of an air relief valve on a pump? - (correct Answer) - Prevent Air Locking
, What is the MCL for Arsenic in mg/l? - (correct Answer) - 0.01 mg/l
Which of the following substances combines with Magnesium to give a laxative affect to the water ? -
(correct Answer) - Sulphates
You are the operator of a community water system located in anywhere New Mexico, anywhere is
required to collect a minimum of three compliance samples per month for a Total Coliform analysis. In
April one of Anywhere's water system samples reported as Total Coliform positive all repeat samples
collected, were reported Total Coliform negative. During May the anywhere water system reported a
routine sample as total Coliform positive. One of the May repeat. Samples reported as fecal chloroform
positive. Which of the following statements is correct? - (correct Answer) - This is an acute MCL violation
and public notification is required
In the situation described in the preceding questions, how many BACT compliance samples must be
collected by the Anywhere water system in June? - (correct Answer) - 5
An operator has discovered that a log has been cut from the hatch of a distribution system storage tank.
Until the incident is confirmed, treat this type of security breach as? - (correct Answer) - A potential
contamination threat
If an insufficient amount of chlorine is used for disinfection. The total chlorine residual may be made of
up combined chlorine residual causing a problem with taste and order. What causes this problem? -
(correct Answer) - Deconstruction of chlorine compounds
What does a reduction in specific capacity indicate? - (correct Answer) - Pumping cost increase
Which of the following is the least important in caring out a jar test? - (correct Answer) - Chloride
concentration
A water system serving 14,000 people has a service water treatment plant that includes it's conventional
treatment. Coagulation, sedimentation, filtration and chlorine disinfection under the capital, NM utility
operators certification regulations. What level of operator must be placed in charge of the system? -
(correct Answer) - Level lV (4)
What is the usual range for the detention time in a sedimentation basin? - (correct Answer) - 2-4 hours
According to the NM drinking water regulations, what is the maximum number of hours allowed
between a collection of a distribution system sampling and analysis for total coliforms? - (correct
Answer) - 30hrs
In the hench scale test, the proper Polyphosphate dose is the lowest dose that delays noticeable
discoloration for a period of? - (correct Answer) - 4 days
According to the US EPA safe drinking water act regulations. What is the basis for the number of monthly
samples you must collect for BAC-T test? - (correct Answer) - The population served
What is the primary purpose of the OSHA hazard communication standard? - (correct Answer) - To match
hazard warning, labels to all portable containers or written information that identifies hazards associated
with chemicals must be available and understandable to coworkers
