Texas Class D Water Distribution study guide with Questions and Correct Solutions

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