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Class "C" Water Exam | Answered with a
Guaranteed Pass| 2025- 2026
Calcium Hypochlorite A common chemical used in the disenfection of a small water supply is- A Cross Connection A physical connection between a potable water supply and a house well would be- Demand The amount of Chlorine in mg/L that is used by reacting with iron, organics, or bacteria is called? Greenish Yellow color Heavier than air Pungent, Penetrating odor Corrosive All of the following are Physical characteristics of Chlorine gas- Solution feed pump Which of the following would be considered a part of a hypo-chlorinator system?
Flow measuring device According to state requirements, all public water supply wells should be provided with a raised concrete sealing block, screened vents and- The difference in static and pumping levels The drawdown of a water well is determined by- If it is more acidic or base The pH of water indicates- 0 - 14 The pH of water is expressed by a scale of numbers ranging from-
Water that is considered neutral is expressed on the pH scale at- Use of an approved, sterile container Which of the following is a required step in collecting a routine distribution sample for bacteriological testing? Turbidity Sand filtration will remove which of the following from surface water?
A public water supply system should maintain residual pressure of 20 psi and a minimum normal operating pressure of- 50 mg/L 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. Aquifers Water bearing formations beneath the earth's surface that are used as a source of water for public water supplies are- Determine water levels in the well The purpose of an air line on a well is- Reduce the amount of sand pumped The mesh size is an important feature of a well screen because property sized openings should- pH, alkalinity, temperature, and chemical dosage When treating surface water, the process of coagulation will be most affected by the-
When the loss of head gauge indicated between 6 and 10 ft. A rapid sand filter should be backwashed when- 0.2 mg/L free chlorine residual 0.5 mg/L chloramine residual for a surface water supply 0.8 mg/L chloramine residual when using chloramine treatment 0.5 mg/L free chlorine residual for a groundwater supply Which of the following is an acceptable disinfection residual at the far reaches of the distribution system- 8.34 lbs One gallon of water weighs- .433 lbs One foot of water inside a storage vessel will raise a pressure gauge at the bottom of the vessel by- 1000 ft A raw water intake structure may not be constructed within _____ feet of a boat ramp, dock, or marina
Coagulation In surface water treatment the process of causing the fine particles in the water to join together to form larger heavier particles that settle in a clarifier is called- Jar test The test commonly used to determine the chemical dosage for the surface water plant is the ___ test. Can be filtered with additional treatment Cause mud balls and filter plugging Suspended solids are the solids portion that- Coliform A public water system is required to take samples of water for bacteriological analysis. The organism that is used as an indicator is called- Residual Chlorine dosage is demand plus desired ___ Stand pipe
A storage vessel that is the same diameter from the ground to the top and is more than 20 feet but less than 85 feet is called a- 35 psi 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- Hydro pneumatic tank A water tank that uses compressed air over water to provide pressure is called a- 8.0% 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. Red When testing for chlorine residual DPD is used as an indicator, when DPD is added to water containing chlorine what color does the sample turn? Gate valve The most common valve(s) used for isolating a water leak is the ___ valve. Water hammer
Call for assistance and wait Put on a self contained breathing apparatus and attach lifeline Once assistance arrives-enter the room and shut off the valve on the cylinder and wait for exhaust fan to evacuate chlorine from room If an operator discovers a chlorine leak on a 150 lb. cylinder inside a room he/she should immediately- 9 feet Waterlines should be installed no closer than___ feet to any sewer lines or other possible contaminate lines. 65 - 75% Calcium Hypochlorite (HTH) is used as a disinfectant in small systems, what percentage chlorine is this material typically? 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
A certified operator is doing his/her routine daily check 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 does not belong. What should the operator do?
When calculating area, one will use the standard for pi, what is the standard accepted numerical value for pi? Once every month 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? Must conform to the National Sanitation Foundation (NSF) Standard 60 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? Breakpoint chlorination
The maximum safe withdrawal rate of chlorine for a 150 pound cylinder is- Acid/Base When diluting a strong acid, always add ___ to ___ rather than the reverse.
The normal oxygen content of the atmosphere is ___ %
Any atmosphere that is less than ___ % oxygen should not be entered without an approved self-contained breathing apparatus. Hydrochloric acid Hypochlorous acid When chlorine gas is added to water, what compounds are formed? The Safe Drinking Water Act of 1974 The most important federal law that impacts the water utility industry is? RV Park Hotel/Motel Service Station
An example of a non-community water system would be? Consumer Confidence Report The EPA requires community water systems to provide customers with an annual? 130 gallons When designing systems engineers use a rule of thumb of ___ gallons per person per day when more accurate data not available. 0.6 gpm TCEQ requires community water systems to have a minimum production capacity of ___ per connection at peak demand. Disinfection The most important treatment in water is? Safe for human consumption Free of disease causing organisms Has a chlorine residual Potable water means the water is- Change in water source, Water quality, or Health hazards
Livestock and septic tanks must be no closer than ___ to a public well. 150 feet Underground fuel tanks and septic drainage fields must be at least ___ feet from a public well. 500 feet Feedlots, sewage treatment plants, and landfills must be at least ___ feet from a public well. 12 inches Trenches for laying 6 inch and larger pipe must be at least 18 inches wide and or ___ inches wider than the pipe diameter. 24 to 36 inches The top of a pipe in a trench must be at least ___ from the top of the ground. 4 feet In an excavation ___ feet or deeper a means of exit must be provided. 3 feet above and 25 feet laterally
In an excavation if a ladder is used as a means of exit, it must extend ___ feet above the ground and be secured and within ___ feet laterally of anyone in the excavation. 2 operators with "C" license A groundwater system that serves in excess of 1,000 connections must have at least ___ operator(s) with ___ license to meet minimum state requirements for public water systems. 7.0 and Corrosive It is desirable for the ph of treated water to be above ___ , otherwise ___conditions will exist. 4.0 mg/L Fluorides are naturally occurring in some groundwater. Fluorides in drinking water should not exceed ___ mg/L Iron Red water or red stains may be caused by ___ levels in the water. 30
The rotometer on a gas chlorinator indicates the number of ___ of chlorine fed during a ___ period. 400 lbs. Using a ton cylinder or container, the maximum withdrawal rate should not exceed- Cavitating A pinging sound or rocks bouncing sound coming from the pump typically indicates the pump is ___.
