Water Treatment Operator Level 1 Sample Questions (Water Operator Certification Study Guide) Already Passed

Water Treatment Operator Level 1 Sample Questions (Water Operator Certification Study Guide) Already Passed What are the two important factors impacting the effectiveness of chlorination? ✔✔Concentration of chlorine ...

Water Treatment Operator Level 1 Sample Questions (Water Operator Certification Study Guide) Already Passed What are the two important factors impacting the effectiveness of chlorination? ✔✔Concentration of chlorine and contact time The treatment process that controls corrosion or scaling is known as what? ✔✔Stabilization Permanganate reactions are highly dependent on what factor? ✔✔pH It is hardest to kill the organism that causes what illness? ✔✔Cryptosporidiosis Disinfection of water wells with free chlorine requires exposure for how long and at what concentration? ✔✔12 to 24 hours; 50mg/L Flocculation basins are usually designed to provide for detention times of how long? ✔✔15 to 45 minutes Alum works best in a pH range of what? ✔✔5.8 to 7.5 What has little effect on colloidal particles because of their small size? ✔✔Gravity What natural electrical force keeps colloidal particles apart in water treatment? ✔✔Zeta potential What does the zeta potential measure? ✔✔The number of excess electrons found on the surface of all particulate matter What device collects the settled water as it leaves the sedimentation basin? ✔✔The effluent launder In solid-contact basins with fairly constant water quality parameters, how often should the solids concentration be determined? ✔✔At least twice per day What is the definition of decant? ✔✔To draw off the liquid from a vessel of any size without stirring up bottom sedimentation How often should sedimentation basins with mechanical sludge removal equipment be drained and inspected? ✔✔Once a year What is the most important reason to reduce turbidity? ✔✔To remove pathogens What is the filtration flow rate through a manganese greensand pressure filter at 10 degrees C? ✔✔2 to 3 gpm/sq ft When is a filter ripening? ✔✔When it becomes more efficient in particle removal Virgin greensand can be regenerated by soaking the filter bed for several hours in a chlorine solution of what? ✔✔100 mg/L What precipitates can foul a cation exchange resin? ✔✔Iron and manganese What process works best for sequestering manganese? ✔✔Polyphosphates and chlorine Adding CO2 to water is known as what? ✔✔Recarbonation What must be done in the ion-exchange softening process once the resin can no longer soften water? ✔✔Regeneration What type of analysis, under no circumstances, should a composite sample be collected? ✔✔Bacteriological The number of monthly distribution system chlorine residual samples required is based on what? ✔✔System size What is the ideal indicator for pathogens? ✔✔Coliform group bacteria When one substance is dissolved in another and will not settle out, what is the product called? ✔✔A solution Acids, bases, and salts lacking in carbon are known as what? ✔✔Inorganic compounds What type of violation requires an all clear notification to the public? ✔✔Tier I How many coliform positive samples are allowed each month from water systems that collect less than 40 samples per month? ✔✔1 If a water sample tests positive for coliforms, the system must collect a set of repeat samples within how many hours? ✔✔24 What are the minimum number of service connections/people/days to make up a public water system? ✔✔15/25/60 Where are the sampling points located for required sampling of coliform bacteria in community water system? ✔✔At consumers' faucets The main purpose of mechanical seals is to do what? ✔✔Control water leakage from the stuffing box The purpose of packing is to do what? ✔✔Control water leakage along the pump's shaft What part of a pump houses the packing or mechanical seal? ✔✔The stuffing box What is the only type of pump that can be operated against a closed valve? ✔✔A centrifugal pump What is a principal problem associated with the preliminary treatment screening? ✔✔Clogging What is the most important thing to consider in automatic startup after a power failure? ✔✔Operator safety At what range of temperature will fusible plugs on chlorine cylinders melt? ✔✔157 to 162 degrees F When should a new gasket be used when a chlorine cylinder is changed out? ✔✔Every time What is the best type of gasket to be used when connecting a chlorine cylinder or container to the chlorine feed system? ✔✔Lead gasket What part of the human body is the most vulnerable to allowing microorganisms to enter? ✔✔Eyes What are the organisms used to indicate the likelihood that pathogenic bacteria may be present? ✔✔Coliform bacteria What adverse effects does the secondary contaminant manganese have? ✔✔Discolored laundry and changed taste in water, coffee, tea, and other beverages In general, what causes an increase in taste and odors when natural waters lack dissolved oxygen? ✔✔Anaerobic decomposition What physical property, as opposed to a chemical property, is important to water treatment? ✔✔Turbidity What are the two principal chemicals that cause water hardness? ✔✔Calcium and magnesium