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TCEQ class c water license exam with
complete solutions
State Agency responsince for enforcing the safe drinking water act in Texas
Texas Commission on environmental Quality
What minerals can cause water hardness
Calcium and magnesium
A public water system must at all times provide
Adequate quantity of water, pressure, and disinfection
A source groundwater would be
aquifer
Fecal coliform organisms sometimes found in water supplies are an indication that
Water supply is contaminated, harmful bacteria may be present, possible pathogenic organisms in the water, water is unsuitable for drinking
A disease that may be spread by inadequately disinfected water
Dysentery
A common chemical used in disinfection of small water supply is
Calcium hypochlorite
A physical connection between a potable water supply and house well would be
A cross connection
The amount of chlorine in mg/L that is used up by reacting with iron organics of bacteria is called
Demand
Which of the following is a physical characteristic of chlorine gas
Greenish-Yellow Color, heavier than air, pungent penetrating odor, corrosive
Which of the following would be considered a part of a hypo-chlorinator system
Solution feed pump
According to state requirements, all public water Supply wells should be provided with a raised concrete sealing block, screened vents, and-
A flow measuring device
Drawdown of a water well is determined by
Difference in static and pumping levels
pH of water indicates
If it's acidic or basic
The pH of water is expressed on a pH scale of
0 - 14
Water that is considered neutral is expressed on the pH scale at
Before a new or repaired water line is placed into service, it must be properly disinfected by providing a chlorine dosage of _________ and proper detention time
50 mg/L
Water bearing formations beneath the earths surface that are used as a source of water for public water supplies are
Aquifers
The purpose of an air line on a well is
Determine Water leves in the well
The mesh size is an important feature of a well screen because properly sized openings should
Reduce the amount of Sand pumped
When treating surface Water, the process of coagularon will be most affected by the
pH, alkalinity, temperature, and chemical Dosage
A rapid sand filter should be backwashed When
The loss of head gauge indicated between 6 and 10 feet
Which of the following is an acceptable disinfection residual at the far reaches of the distribution System
0.2 mg/L free chlorine residual, 0.8 mg/L chloramine residual when using chloramine treatment, 0.5 mg/L chloramine for surface water supply, 0.5 mg/L free chlorine residual for ground water Supply
What is the approximate total volume of a circular tank in gallons, if it is 30 feet in diameter, and 15 feet deep
79,300 gallons
You are using a chlorinator to provine a dosage of 4.0 mg/L. If the daily Water usage is 750, gallons, the gas chlorinator feed rate should be set at ____________ pounds per day.
25
One gallon of water weighs
8.34 lbs.
One foot of water inside a storage vessel will raise a pressure gauge at the bottom of the vessel by
0.433 lbs. (1 ft. Water creates 0.433 psi of pressure)
A raw water intake structure may not be constructed with ___________ feet of a boat ramp, dock, or marina
1,000 feet
Cause mudballs and filter plugging
A public Water system is required to take samples of water for bacteriological analysis. The organism that is used as an indicator is
Coliform
Chisine dosage is demand plus desired
Residual
A storage vessel that is the same diameter from the ground to the top and is more than 20 feet but less than 80 feet tall is called a
Stand pipe
Potable water must be stored at an elevation at least 80.85 feet above the highest known connection to provide the minimum operating pressure of _____ psi
35
Water tank that uses compressed air over water to provide pressure is called a
Hydro pneumatic tank
According to the lead and copper rule, pipe and fittings may not contain more than __________ lead or solder and flux may not contain more than 0.2% lead
8.0%
When testing for chlorine residual DPD is used as an indicator, when DPD is added to Water containing Chlorine what loser does the sample turn
Red
Most commonly used valves for isolating a water leak is the
Gate valve
In the distribution system when a valve or hydrant is opened or closed too fast it could result in a
Water hammer
The most commonly used pump in the distribution system is
Centrifugal
You are treating 21 MGD water in a surface Water plant, how many gallons per minute is this?
14,583 gallons per minute
A class D certified Operator can operate a public water system up to _________ connections
250
All state of Texas operator licenses after issue are good for _________ years
3
After analyzing monthly bacteriological samples the operator is notified that one testing point, tested positive. The operator should-
Collect another sample at the site that tested positive plus one within 5 customers upstream and one within 5 customers downstream and re-submit
Any excavation greater than _________ feet in depth requires the use of OSHA approved shoring equipment or sloping of walls to prevent cave -ins
Calcium hypochlorite (HTH) is used as a disinfectant in small systems, what percentage chorine is this material typically?
65%-75%
A certified operator doing their routine daily checks of wells, pumps, and storage facilities discovers a cut lock on the entry gate, there is also a cut lock on the roof hatch to the storage tank and suspicious looking containers lying on the ground that do not belong. What should the Operator do?
- Immediately notify TCEQ Regional office and they will notify law enforcement and investigate to determine if there is a danger or threat to public health and safety
- pull the electrical disconnect on the pumps and close valves isolating the tank until it can be analyzed
When calculating area one will use the standard for pi what is the standard numerical value for pi?
Flushing dead-end mains - current state regulations require that all public water Systems flush dead-end mains to assure chlorine residual and water quality. What is the minimum flushing requirement?
Once every month
In small systems liquid bleach is an approved method of disinfection, provided the product used meets basic industry standards. What is the current standard bleach must meet in order to be approved for disinfection in a public water system?
Must conform to the national sanitation foundation (NSF) standard 60
The process of adding enough chlorine to a water supply to complete all reactions with reducing compounds, ammonia, and organic materials so that some free Chlorine is left called -
Break point chlorine
The primary reason for main line failures in the distribution system is -
- internal and external corrosion
- improper backfill and lack of proper bedding
Check values on the discharge side of a pump are used to-
Prevent water from flowing back through the pump when the pump is off
_____________ & ____________ acids are by products of drinking water
Trinalomethanes, Haloacetic
These are ______ major underground water aquifers in Texas
7
Most common type of filter in a surface plant is _________ and is designed to treat and flow at-
Rapid sand and designed to flow 2 gpm/ft
When diluting a strong acid always add _______ to ________ rather than the reverse
Acid/Base
Normal oxygen content in the atmosphere is _______%
Any atmosphere that is less than ________% oxygen should not be entered without an approved self-contained breathing apparatus
When chlorine gas is added to water, what compounds are formed?
Hydrochloric and hypochlorous acid
The most important federal law that impacts the water utility industry is -
The safe drinking water act of 1974
An example of a non-community water system is
Rv Park, hotel/motel, Service station
The EPA requires community water systems to provide customers with an annual-
Consumer confidence report
When designing systems engineers use a rule of thumb of _______ gallons per person per day when more accurate data isn't available
130
TCEQ requires community water systems to have a minimum production capacity of _______ per connection at peak demand
0.6 gpm
The most important treatment in water is-
Disinfection
Potable water means the water is
- Safe for human consumption
- has a chlorine residual
- free of disease causing organisms
TCEQ requires notification from the operator if changes to the public water system occur such as
Change in water source, water quality, or health hazards
Public water systems in Texas are required to compile and maintain reports showing
- Pumps and chemical usage
- date of dead-end flushing and storage tanks cleared
- microbial tests and chemical tests
Physical characteristics of water include
Taste, odor, Color, turbidity, and temperature
Common gases found in water are hydrogen sulfide, Carbon dioxide, and methane. Hydrogen sulfide can be identified by its distinct smell, which is
Rotten eggs and obnoxious
3 and 25
A groundwater system that serves in excess of 1,000 connections must have at least _______ operators with _______ license to meet minimum State requirements for public water systems
2 and c
A groundwater well is currently pumping 1,000 gallons per minute. Convert 1,000 gpm to million gallons per day (MGD)
1.44 MGD
It is desirable for pH of treated water to be above _______ otherwise _______ conditions will exist
7.0 and corrosive
Fluorides are naturally occurring in some groundwater. Fluorides in drinking water should not exceed
4.0 mg/L
Red water or red stains may be caused by _________ levels in water
Iron
When chemicals are used at a water treatment plant a _______ day supply should be kept on hand at all times to comply with State standards
The presence of iron in water is most commonly treated by
Aeration
A common chemical oxidizer is
Potassium permanganate
If groundwater is to be treated for several problems, the first process should be
Aeration
Excess fluoride in water may be removed by
Activated alumina
Trihalomethanes are formed by the reaction of _______ with organic chemicals
Free available Chlorine
TCEQ requests a water system to have disinfection equipment capable of providing at least _______% greater capacity than the highest expected dosage at any time
50
The rotometer on a gas chlorinator indicates the number of _______ of chlorine fed during a _______ period
Pounds/24 hours
A dosage of 4.0 mg/l is added to 750,000 gallons of water. How many pounds of chlorine are needed?
The distance of the water level in the well to the Water level in a storage tank is
Total static head
The loss of energy which results from the movement of water through pipes and fittings is
Friction
If a water lubricated vertical turbine pump is started by dry bearings
The bearings will be damaged
Routinely measuring the static level and pumping level can
Detect problems with the pump, well screen, and/or water level
The recommended capacities for ground storage is based on providing _______ to _______ hours of apply at _______ gallons per connection
4 to 6 hours at 200 gallons per connection
Five codes require water main sizes in residential areas to be at least _______ when fire hydrants are attached
6 inch
Flow in pipes depends greatly on pipe diameter. Doubling the pipe diameter increases the carrying capacity by _______ times if friction is not considered
4 times
Unaccounted for water loss should be less than ________% of water production
15
A critical factor affecting the useful life of service lines is the ability of the pipe material to resist internal and external
Corrosion
The results of bacteriological analysis shall be kept on file and available for _______ years
5
A well pumped for 45 days. The beginning meter reading was 7,456,400 and 45 days later the same meter reading was 15,154,400. What was the average flow in gallons per day?
171,
One horsepower (1 hp) is equal to _______ feet pounds Of force per minute
33,000 feet pounds
A groundwater well is currently producing 1.4 MGD. Calculate and convent 1.4 MGD to GPM
972 gpm
Elevated storage is required for systems over _______connections
