Download Texas Class C Surface Water Exam Review: Questions and Answers and more Exams Water Resources Planning and Management in PDF only on Docsity!
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Texas Class C Surface Water Exam
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A disease that cannot be contracted by drinking contaminated water is: - ANSWER Malaria
A non-permit confined space by OSHA standards means a confined space that: - ANSWER Does not contain or have the potential to contain any hazard capable of causing death
When used in connection with the Safe Drinking Water Act, the term "MCL" means: - ANSWER Maximum Contaminant Level
Examples of non-community water systems include: - ANSWER Highway rest areas
The TCEQ requires that results be recorded and submitted daily for surface water supplies for: - ANSWER Disinfectant residuals, turbidity, total solids, pH, alkalinity
tracking and maintaining an operator's training records is ultimately the responsibility of the: - ANSWER Operator
An employee without a breathing apparatus is in a room where chlorine gas suddenly begins leaking. What should the employee do first? - ANSWER Keep mouth closed, keep head as high as possible, and quickly walk out of the room, holding their breath if possible
Before changing a gas chlorine cylinder in a room, the first step should be: - ANSWER Start the exhaust vent fan
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Waterworks operator's holding grade c certificates are required to renew their certificates every three years and to: - ANSWER Inform the TCEQ of any address changes
In order to insure that the water produced meets TCEQ standards, each surface water treatment plant must have a surface water operator on duty at all times when the plant is in operation or the plant must be provided with: - ANSWER Continuous turbidity and disinfectant residual monitors, automatic alarm systems, and an automatic shutdown system
The major responsibility of a certified waterworks operator is to: - ANSWER Insure that a safe and adequate supply of drinking water is delivered to the customer's tap
According to the TCEQ, a public water system is defined as any water system that provides piped water for human consumption to at least (a) service connections on a year-round basis or regularly serves (b) individuals daily at least_(c)_ days out of the year. - ANSWER (a) 15; (b) 25; (c) 60
Most of the surface water in Texas comes from: - ANSWER Precipitation that falls within the state
The most important factor in preventing accidents is: - ANSWER The attitude of the employee
Organics in surface water will combine with halogens to form: - ANSWER Trihalomethanes
According to the average annual water budget for Texas, the majority of surface water leaves the state by: - ANSWER Evaporation and transpiration
The term water stabilization refers to: - ANSWER pH adjustment
Which pH measurements would indicate that water is basic: (6.0; 6.9; 7.0; 8.3) - ANSWER 8.
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Sedimentation is improved by: - ANSWER Uniform, horizontal, low velocity flow across the basin
The most important water quality change in filter effluent is: - ANSWER Turbidity
Soda ash is used in water treatment processes to: - ANSWER Adjust pH
A sand filter will not remove: - ANSWER Dissolved oxygen
The occurrence of mud balls in beds of filters may be prevented by: - ANSWER Proper sedimentation
The loss-of-head through a sand filter bed is influenced by: - ANSWER Sand particle size, filtration rate, water temperature, and the concentration of dissolved gas
The term floc refers to: - ANSWER The flecks of coagulant containing trapped suspended matter
The maximum flow rate through a sand filter should be: - ANSWER 2-4 GPM per square foot
Baffles are used to prevent short-circuiting in: - ANSWER Sedimentation basins
Filter underdrains or bottoms serve several important purposes including: - ANSWER Deliver the backwash water uniformly underneath the filter media
Jar tests are used to determine the: - ANSWER Correct chemical dosage
The Rules and Regulations for Public Water Systems states that minimum pressures in all water distribution systems must not be less than 20 psi and that normal operating pressures must not be less than: - ANSWER 35 psi
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The State Board of Insurance recommended capacity for ground storage includes: - ANSWER 4-6 hour supply, 130 gallons per capita, 200 gallons per connection
An altitude valve is used to: - ANSWER Control the water elevation in an elevated storage tank
Two pressure gauges at the foot of two storage tanks are at the same elevation. The water levels in the two tanks are the same, but tank X holds, 1,000,000 gallons of water and tank Y holds 500,000 gallons. The gauge on tank X will have a reading of: - ANSWER The same as that of tank Y
The capacity of a centrifugal pump will be decreased by: - ANSWER Insufficient suction head
A standpipe: - ANSWER Has a diameter less than it's height
The most effective method of cross connection control is: - ANSWER A physical air gap
If using the combined available chlorine residual (CACR) method of disinfections: - ANSWER When water temperature decreases, the CACR must be increased in order to maintain proper chlorine residuals
After installation or repair of a water line, it should be treated with: - ANSWER 50 mg/L of chlorine for 24 hours
Calcium hypochlorite: - ANSWER is 60%-70% chlorine
Chlorine gas: - ANSWER Is highly toxic and can be fatal; is corrosive in damp surroundings
The Rules and Regulations for Public Water Systems states that distributions systems must maintain a chlorine residual of: - ANSWER 0.2 mg/L of free chlorine or 0.5 mg/L of chloramines in the far reaches of the distribution system
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The volume of a 100 ft. diameter tank that is 12 ft. deep is ___ ft^3. - ANSWER 94,200 ft^
A chemical commonly used to raise pH is: - ANSWER Lime (Soda ash)
Black stains on plumbing fixtures might be attributed to what? - ANSWER Manganese
One kilogram equals ___ grams - ANSWER 1000
The indicator organisms used to determine contamination of drinking water are: - ANSWER Coliform groups
The packing around the shaft of a centrifugal pump should be: - ANSWER Tightened just enough to allow an occasional drop of liquid to escape
The chemical symbol of iron is: - ANSWER Fe
One pound of pressure will raise water ___ ft. - ANSWER 2.31 ft.
Static head is defined as the: - ANSWER Pressure due to depth or elevation of water
What is the volume of a settling tank 100 ft. long, 25 ft. wide, and 8 ft. deep? - ANSWER 20,000 ft^
What is used to detect chlorine leaks? - ANSWER 10% solution of ammonia hydroxide (ammonia)
The pressure gauge reading at the base of a tank filled to a depth of 1 ft. is ___ psi - ANSWER 0.433 psi
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The multiple-tube fermentation test consists of three distinct tests. These tests, in the order performed, are: - ANSWER Presumptive, confirmed, and completed tests
Chlorine gas is more or less dense than air? - ANSWER More dense than air
Polyphosphates may be used in water treatment to retard corrosion and: - ANSWER Calcium scale
Calcium hypochlorite is formulated as a: - ANSWER Powder
Chlorine leaks in metal containers tend to become: - ANSWER Larger
Determining the pH of water is one of the important tests of water quality. The results of the pH test indicate the: - ANSWER Hydrogen ion activity
Alkalinity is a direct measure of water's capability to resists changes in: - ANSWER pH (acidity)
Leakage form a packing gland should be approximately: - ANSWER One drop per second
A chlorine cylinder valve is thought to be leaking. If ammonia vapor is passed near the valve, the presence of a leak would be indicated by: - ANSWER White smoke
If a fire hydrant requires a nozzle pressure of 100 psi, what head of water must be used to supply it? - ANSWER 231 ft.
Which type of pipe is most likely to be damaged by corrosion? - ANSWER Steel
Carbon dioxide in water will do what to the pH? - ANSWER Lower the pH
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What is the approximate volume in gallons occupied by 15,000 ft^3 of water? - ANSWER 112,200 gallons
The difference between the amount of chlorine added to water and the amount of residual chlorine at the end of a specified contact time is called what? - ANSWER Chlorine Demand
Water that requires a large amount of soap to produce an acceptable lather is said to be what? - ANSWER Hard
A pump may be damaged if it is started with the discharge valve closed, and the pump is a(n): - ANSWER Positive displacement pump
Prepared water sample bottles used for collecting samples for bacteriological examination contain sodium thiosulfate crystals. It is important not to rinse out the sample bottle because the sodium thiosulfate does what? - ANSWER Neutralizes any chlorine present in the sample
Velocity of flow in water mains is usually expressed in terms of: - ANSWER Feet per second
A pH reading of 6.0 in raw water indicates the sample is what? - ANSWER Acidic
The temperature of water in a stream is 10 C. What is the equivalent temperature in F? - ANSWER 50 F
A grab sample represents the quality of the water when? - ANSWER Only when the sample was taken
The pH scale runs from ___ to ___ - ANSWER 0-
Five gallons of water weighs ___ lbs - ANSWER 41.7 lbs
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What is the approximate weight, in pounds, of 50,000 gallons of water? - ANSWER 417,000 lbs
The flow in 35,000 gallons per day. What is that in MGD? - ANSWER 0.035 MGD
The most important factor affecting the useful life of piping is the ability of that piping to resist what? - ANSWER Moisture of any kind
A pH value of 7.0 is considered to be what? - ANSWER Neutral
The discharge pressure gauge on a pump reads 15 psi. This is equivalent to ___ ft. of head - ANSWER 35 ft
Chlorine is very corrosive when combined with what? - ANSWER Moisture of any kind
What is the surface area of a clarifier 40 ft. in diameter? - ANSWER 1256 ft^
Chloramines are formed by the addition of chlorine and what other chemical? - ANSWER Ammonia
The purpose of a rotameter is to meter the flow of what? - ANSWER Chlorine gas (or any gas for that matter)
A valve that joins a customer's service to the water main is called the ____ - ANSWER Corporation cock
When compared to a 1-million gallon reservoir at the same elevation, how much pressure in the mains will a 100,000 gallon reservoir develop? (assume equal elevation for both) - ANSWER The same pressure
What information must be on a warning tag attached to a switch that has been locked out? - ANSWER Signature of person who locked out the switch and who is the only person authorized to remove the tag
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One of the purposes of water storage tanks is to ____ - ANSWER Supply water at peak demands
Mud, silt, clay, and other suspended matter in water that cause it to appear murky are called what? - ANSWER Turbidity
If the pressure gauge at the bottom of a 200 ft. standpipe reads 68 psi, what is the static head in feet? - ANSWER 157 ft
The volume of a sample should depend on what? - ANSWER What tests the sample will be used for
What does a pump need when the gland follower is pulled all the way down? - ANSWER A new packing
Sodium hypochlorite is a compound that can be purchased in liquid solution and be used for what? - ANSWER Disinfection
Gas chlorinators, when operated at high rates, can result in what? - ANSWER Ice formation on the chlorine cylinder
When a single water sample is reported as safe, this may be interpreted to mean what? - ANSWER That the water supply was safe at the sample point, at the time of the sampling
In loading or unloading 150 lb chlorine cylinders, hand trucks should be used that are equipped with what? - ANSWER A retaining or safety chain
What does "gpm" stand for? - ANSWER Gallons per minute
The amount of dissolved oxygen that can remain in water depends primarily on what? - ANSWER Water temperature
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A flow of 1.55 ft^3 per second is ___ gpm - ANSWER 696 gpm
What is the chlorine demand if the residual is 0.6 mg/L and 6.6 mg/L has been applied? - ANSWER 6. mg/L
The effective pH range for iron and manganese removal is ____ to ____ - ANSWER 8-
How many gallons per minute is a flow of 1.0 MGD? - ANSWER 695 gpm
Disease producing organisms are commonly called what? - ANSWER Pathogens
The DPD test method for chlorine residual usually involves using what? - ANSWER A color comparator
If a simple piezometer is inserted into a pipe containing water under a pressure of 50 psi, water would rise in the tube to a height of ___ ft - ANSWER 115 ft
Vent openings on reservoirs and clearwells should be - ANSWER screened
You are chlorinating a well supply and the chlorine demand jumps from 0.9 mg/L to 3.0 mg/L. This is indicative of ___ - ANSWER Pollution of some kind
