Water Treatment Exam Preparation Grade 2 with complete solution

____ and/or _________ in a water supply can discolor laundry, cause a bad taste in the water, and cause taste problems in beverages such as coffee and tea. - ANSWER Iron and/or Manganese Water systems that collect less than _____ coliform samples each month can have 1 positive sample and remain in compliance. - ANSWER 40 The maximum contaminant level for bromate is _____ mg/L. - ANSWER 0.010 mg/L Water systems must provide at least _____ removal or inactivation of Giardia lamblia cysts between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer. - ANSWER 3-log ____ _______ is the best available technology for removing radium-226 and radium-228 from a water supply. - ANSWER Lime softening Color gives the water an unappealing appearance and indicates that _______ _______ may be present. - ANSWER dissolved organics Water systems must provide at least 4-log removal or inactivation of viruses between a point where the raw water is not subject to recontamination by surface water runoff and a point downstream before or at the first customer. - ANSWER 4-log For water systems using conventional treatment or direct filtration, the turbidity level of representative samples of a system's filtered water must be less than or equal to _____ NTU in at least 95% of the samples collected each month. - ANSWER 0.3 A public water system that does not provide filtration must have a disinfection concentration in the distribution system, measured as total chlorine, combined chlorine, or chlorine dioxide, which cannot be undetectable in more than _____% of the samples each - ANSWER 5% Systems using diatomaceous earth filtration are required to have turbidity levels _____ ntu in ____% of the measurements collected each month. - ANSWER ≤1.0 ntu in 95% Lab analysis of pH, turbidity, temperature, and residual disinfectant concentrations must be performed by a person approved by the ______. - ANSWER State Either the _____ or a _____ _______ certifies water treatment plant laboratories for the measurement of total coliforms, fecal coliforms, and heterotrophic plate counts. - ANSWER USEPA or a state agency The time from sample collection to initiation of the fecal coliform analysis may not exceed _____ hours. - ANSWER 8 hours Samples to be analyzed for total coliforms by the total coliform Fermentation Technique, must be kept below _____ degrees Celsius during transit. - ANSWER 10 degrees Celsius Utilities collecting samples more frequently than annually for inorganic contaminants determine MCL compliance by calculating a ______ ______ _______ at each compliance sample point. - ANSWER running annual average A Tier _ violation poses immediate risk to public health and requires a clear notification to the public within __ ______ of learning of the violation. - ANSWER 24 hours Water systems avoiding filtration of source water must show that the turbidity of the source water immediately before the initial point of disinfection has not exceeded __ NTU in __% of the samples analyzed in the previous 6 months. - ANSWER 5.0 NTU in 90% A Tier _ violation requires the water system to notify its customers as soon as possible, but within 30 days of learning of the violation and continue ________ notifications as long as the violation persists. - ANSWER quarterly Solder or flux is considered lead free if it does not contain more than ___% lead. - ANSWER 0.2% A Tier _ violation requires the public water system to notify its customers within 12 months of learning of the violation. This may be accomplished by including the violation in the ________ _________ Report - ANSWER Consumer Confidence Repeat samples for a positive coliform sample are required to be collected within ____ hours. - ANSWER 24 hours A water system is considered public if it has at least ____ service connections or serves ____ or more persons ____ or more days each year. - ANSWER -15 service connections -25 or more persons -60 or more days each year Total _______ samples must be collected at sites which are representative of water quality throughout the distribution system according to a written ______ _____ _____ subject to state review and revision. - ANSWER -Coliform