Test questions
How long will it take for suspended solids to settle
4 hours
Fluoride levels above_____mg/l will cause teeth to become pitted or discolored.
4 mg/l
The maximum chlorine gas withdrawal rate from a one ton container at 70 degrees is
400 lb/day
What percent of total coliform samples can be positive and the system remain in compliance if they collect 40 or more samples each month?
5%
What is the normal strength of sodium hypochlorite as percent available Chlorine?
5-15%
Calcium hypochlorite is usually available in what strength?
65-70%
The depression produced in a water table when pumping water from a well is called:
Come of depression
What is considered to be "Lead free" as it relates to solder and flux?
Containing not more than 0.02% lead
What chemical is used to control an algal bloom?
Copper sulfate
What are the three routine control tests performed on an aeration system?
DO, pH, Temperature
What pump is accurate and will operate against pressure?
Diaphragm pump
What type of PAC feed system should a plant that plans to only feed powdered activates carbon periodically installed?
Dry feed system
A plan that lists the sample locations and sample frequencies for coliform monitoring is called:
Sample sitting plan
What zone lies beneath the water table?
Saturated zone
Where are the sampling points located for required sampling of coliform bacteria in a community water system?
Sites which are representative of water quality throughout the distribution
From the list below, which chemical will raise pH
Soda ash
Which chemical improves coagulation when used with alum?
Sodium alluminate
From the list below which chemical will raise pH?
Sodium hydroxide
Lab analysis of pH, turbidity, temperature, and residual disinfectant concentrations must be performed by
State
Carbon dioxide is removed from water by the aeration process due to:
Stripping
Powdered activated carbon systems are normally installed to control:
Taste and odors
When softening water using the lime soda ash softening process, soda ash dosage is based on:
The amount of non-carbonate hardness to be removed
Which statement is true regarding one-Tom chlorine containers?
They are equipped with two valves, one for liquid, one for gas
Which type of violation requires an all clear notification to the public?
Tier 1
What is the purpose of a bypass on a large gate valve?
To equalized pressure prior to opening
Why is air added during the reverse flow process of a micro filtration plant?
To improve the removal of fouling material
What is the purpose of fusible plugs on chlorine cylinders?
To prevent over pressuring the chlorine cylinder due to high pressure
The purpose of the vacuum relief valve in the line going to the chlorine injector is:
To shut off chlorine gas flow in case of a leak
The buildup of corrosion products on the inside of iron pipes is known as...
Tuberculation
All suspended matter in water is called:
Turbidity
Membrane processes capable of removing bacteria, Protozoa, viruses, and organic molecules are:
Ultra filtration, nano filtration, and reverse osmosis
What volume of sample is collected for the presence-absence coliform determination test?
100 ml
The approximate surface area of 1 pound is GAC is:
150 acres
At what temp will a chlorine cylinder fusible plug melt?
158-165 Fahrenheit
Which would be considered very hard water measured in my/l as CaCO3?
200 mg/l
What is a typical filter run time for a high-rate filter system?
24 hours
When should a water system using polyphosphates for iron and manganese sequestration inject the chemical?
Immediately after the water leaves the well
Ion exchange softening processes can be used for direct groundwater treatment as long as turbidity and ______ levels are not too high.
Iron
When added to treated water, sodium polyphosphate:
Is a sequestering agent
Which membrane process has been used for water softening and DBP precursor removal?
Nano-filtration
How many samples can coliform be positive is a water system collects less than 40 samples?
1
Systems that collect fewer than 40 coliform samples each month are allowed ________ positive samples without violating the total coliform rule.
1
The maximum contaminate level for bromate is:
0.010%
If sequestration of iron and manganese is practiced, the chlorine residual in the water system should always be maintained at or above:
0.2 mg/l
What is the term "C Value" a description of?
A number that describes the smoothness of a pipes interior surface
What is it called when one substance is dissolved in another and will not settle out?
A solution
Following the lime softening process, how is the water stabilized?
Addition of carbon dioxide
Where should a GAC process be installed at a surface water treatment plant?
After filtration
What is the purpose of a check valve?
Allow one flow in only one direction
When/Where is powdered activated carbon (PAC) usually added to the treatment process?
Before coagulation-flocculation process
Which are the two main elements that cause water hardness?
Calcium and magnesium
Hard water scale is usually caused by:
Calcium carbonate
Which of the following is most commonly used to disinfect the gravel packing of a groundwater wel?
Calcium hypochlorite
What type of force or forces are involved in the adsorption process?
Chemical and physical
Trihalomethane's are usually associated with:
Chlorinated surface waters high in natural organic matter
In addition to drinking water regulations, what regulation may govern the operation of a packed tower aeration system?
Clean air act
Which commonly used base material produces an activated carbon with the smallest pore size of those listed?
Coconut shell
Which of the following material groups are commonly used for GAC?
Coconut shell, bituminous coal
The minimum treatment required for a surface water system is to treat the water for:
Coliform bacteria and turbidity
What are the two major classifications of membrane processes?
Electric driven, pressure driven
How often should greased bearings be lubricated when in full service?
Every 3-6 months
According to the Surface Water Treatment rule, how often must a system serving more than 500 people sample their filtered water for turbidity?
Every 4 hours
What is used to transfer power from an electric motor to a centrifugal pump?
Flexible coupling
Sodium flouride
Has no odor
For direct filtration or conventional treatment the turbidity level must be:
Less than or equal to 0.3 ntu in at least 95%
Turbidity in a slow sand filter must be:
Less than or equal to 1.0 NYU in 95%
What are the turbidity requirements for the diatomaceous earth filtration?
Less than or equal to 1.0 ntu in 95%
What principle does the turbidimeter operate on?
Light deflection
Which chemical used in water treatment will increase pH, hardness, and alkalinity?
Lime
Raw water can usually be softened by only using lime when it contains:
Little or no non-carbonate hardness
What hazardous condition can be created when activated carbon inside a tank gets wet?
Low oxegen atmosphere
For public water systems operating without filtration, the surface water treatment rule requires them to:
Maintain a CxT value above the minimum required
The most common solution feeder used for liquid coagulants and coagulant aids is the:
Metering pump
From the following list which is an indication of bearing failure?
Noise coming from pump
What agency is responsible for establishing regulations to ensure the health and safety of employees?
OSHA
What action should you take before beginning work on a chemical feed pump?
Open the breaker and lock it out
When you are working on a piece of electrical equipment, what should you do to the circuit breaker?
Open the breaker and lock it out
In a micro-filtration facility, which membrane material is most resistant to strong oxidants and acids?
PVDF
Which aeration method is most commonly used for volatile organic chemical removal?
Packed tower Aeration
A pump that delivers a fixed volume of liquid with each stroke, regardless of system pressure is a:
Piston type pump
Calcium hypochlorite usually comes in what form?
Powder
Which of the following list of tests is used to determine compliance for total coliforms?
Presence-Absence method
From the list below, choose the aeration method that is not a water into air type of aerator:
Pressure
What is the function of sodium thiosulfate in the coloform sample bottle?
Remove chlorine residual prior to analysis
What is the cause of pressure head?
Water elevation
How does water temperature impact the solubility of gases in water?
Water temperature and solubility are inversely related
If ammonia vapor combines with chlorine gas leaking from a cylinder, what will appear?
White cloud
How would you describe the appearance of sodium hypochlorite?
Yellow liquid
