Texas Class D Water Distribution Study Guide 100% Correct

Texas Class D Water Distribution Study Guide 100% Correct What is the name of the State Agency responsible for enforcing the Safe Drinking Water Act? Texas Commission on Environmental Quality what Minerals are associated with water hardness? Calcium and magnesium A public water system MUST at all times provide? A. Adequate quantity of water B. Adequate water pressure c. Adequate disinfection D. All of the above D. All of the above A Source of groundwater would be? Aquifer Fecal Coliform organisms sometimes found in water supplies are an indication that? A. The water Supply is Contaminated B. Harmful Bacteria may be present C. Possible pathogenic organisms are in the water D. The water is unsuitable for drinking E. All of the above E. All of the above A disease that may be spread by inadequately disinfected water is Dysentery A Common Chemical used in the disinfection of a small water Supply is Calcium hypochlorite A public water Supply system should maintain a system residual pressure of 20 psi and a minimum normal operating pressure of _____ 35 psi The amount of chlorine in mg/L that is used by reacting with iron, organics or bacteria is called Demand The MOST important treatment in water is Disinfection Which of the following would be considered part(s) of a hypo-chlorinator system Solution feed pump According to state requirements all public water supply wells shall be provided with a raised concrete sealing block screen vents and Flow Measuring Device One method to determine the drawdown of a water well is An air line The pH of the water indicates If it is more acid or base Assuming you collect more than 1 bac-t sample monthly and your system receives notification from the lab that one of the samples taken in the distribution system comes back positive your repeat sample(s) must be taken within _____ hours and a total of _____ repeat samples must be collected for each positive? 24 hours and 3 repeat samples Water that is considered neutral is expressed on the pH scale at 7 Which of the following is a required step in collecting a routine distribution sample for bacteriological testing? Use an approved, sterile sample container Potable water means that the water is A. Maintained at adequate pressure B. Pathogen free C. Contains a chlorine residual D. All of the above E. B & C only All of the above 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 Should a public water supply systems distribution system drop below 20 psi, what is required of the operator? A. Nothing 20 psi is simply a goal B. Immediately correct the problem or cause of low pressure C. Notify the mayor and city council D. Notify the Regional TCEQ office and issue a "Boil Water Notice" E. Both B and D Both B and D In a groundwater system if the operator knows the " standing" water level in the well when the pump is off and they know the water level in the well during "pumping", they can determine the ________________ of the well. Drawdown TCEQ requires community water systems to have a minimum production capacity of _________ per connection at peak demand .06 gpm The mesh size is an important feature of a well screen because properly sized openings should Reduce the amount of sand pumped Which of the following is an acceptable disinfection residual at the far reaches of the distribution system? A. 0.2 mg/L free residual B. 0.5 mg/L chloramines residual for a surface water supply C. 0.8 mg/L chloramines residual when using chloramines treatment D. 0.5 mg/L free chlorine residual for a ground water supply E. All of the above All of the above 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 .433 lbs Common type(s) of pump(s) for use in water wells are A. Proportion pumps B. Split case C. Vertical turbine D. Submersible E. Both C and D Both Vertical turbine and Submersible ___________________________ is the natural exchange of water between earth and air. Hydrological cycle If and when a health hazard contamination event occurs in a public water system the operator must contact the state regulatory authority within _______ hours by phone 24 hours A physical connection between a potable water supply and a house well would be A cross connection Excessive nitrates in drinking water can cause a condition that affects infants under the age of 6 months the condition is called Blue Baby A public water system is required to take samples of water for bacteriological analysis. The organism that is used as an indicator is called Coliform Chlorine dosage is demand plus desired _______________ Residual A storage vessel that is the same diameter from the ground to the top and is more that 20 feet but less that 85 feet tall is called Stand Pipe A water tank uses compressed air over water to provide pressure is called a Hydro pneumatic tank According to the lead and copper rule pipe and fitting 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 color does the sample turn? Red The most common valve used for isolating a water leak is the _________________ valve Gate Valve In the distribution system when a valve or fire 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 A Texas Class D Certified operator can Operate a public water system up to ______ connections 250 All state of Texas operator licenses after issuance are good for ________ years 3 Waterline should be installed no closer than _______ feet to any sewer lines 9 Calcium hypochlorite (HTH) is used as an disinfectant in small systems what percentage of chlorine is typical? 65% - 75% Flushing dead end mains - what is the minimum Flushing requirements per TCEQ? Once a month The process of adding enough chlorine to a water supply to complete all reaction with reducing compounds, ammonia and organic materials so that some free chlorine is left is called Breakpoint chlorination The Primary reason(s) for main line failures in the distribution system is? A. internal and external corrosion B. Defective materials C. Lake of routine maintenance D. Improper backfill and lake of proper bedding E. Both A and D Both A and D Check valve on the discharge side of a pump are used to Prevents water from flowing back through the pump when the pump is off After disinfection and Flushing of super chlorinated new lines and service, but prior to placing the line into service bacteriological samples are required. The current standard is _____ sample for every _________ feet of main 1 sample for every 1000 feet For cross connection control the TCEQ's preferred method is Physical air gap One microorganisms found in water that is resistant to chlorine is Cryptosporidium 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 would be? A. RV Park B. Hotel/Motel C. Service Station D. A, B, and C E. None of the above RV Park, Hotel/Motel, Service Station The EPA requires community systems to provide customers with an annual? Consumers Confidence Report A Groundwater well is currently producing 820 gallons per minute. Convert 820 gpm to Million Gallons per Day MGD 1.18 In the distribution system where would a person expect to find a valve commonly referred to a curb stop? At the property line and immediately in front of the water meter Public water system in Texas are required to compile and maintain reports showing A. Pumpage and Chemical used B. Date of Dead end Flushing & storage tanks cleaned C. Microbiological test and Chemical analysis D. A & C only E. A, B & C E. A, B & C Groundwater is generally well filtered and free of turbidity, color and organics. however it may be high in Hardness, minerals and inorganics Livestock and septic tanks must be no closer than __________ to a public well 50 feet Feedlots, sewage treatment plants and landfills must at least ______ feet from a public well 500 feet Red water or red stains may be caused by ______ levels in the water. Iron A pinging sound or "rocks bouncing" sound coming from the pump typically indicates a pump is Cavitating In the distribution system where would you find a corporation stop At the providers main line You are treating 21 MGD water. how many gallons per minute is this? 14,583 What is the approximate total volume in gallons of a circular tank if it is 30 feet in diameter and 15 feet deep 79,300 In a groundwater system according to the well drillers report the hole was drilled 338 feet deep - the static level of water in the well is 108 feet - the pumping level is 171 feet. what is the drawdown? 63 feet At the base of an elevated storage tank, a pressure gauge reads 72 psi. How far above the gauge is the water's surface? 166 feet How many pounds of a 70% chlorine (HTH) will be needed to treat the same amount of water as 9.0 lbs of 100% chlorine gas? 12.85 lbs System is pumping 1.4 MGD and using 9.0 mg/L chlorine. The residual at the far end of the distribution system is 0.4 mg/L. What is the Demand? 8.6 mg/L The system is installing 6 miles of 10 inch class 150 pvc water line. The pipe comes in 20 foot sections. How many sections are needed? 1,584