front 1 What are the general water quality characteristics of surface water supplies | back 1 low calcium and magnesium content (soft water), turbidity, suspended solids, some color, and microbial contamination. |
front 2 What are the general water quality characteristics of groundwater supplies | back 2 contains dissolved solids, dissolved gases, high hardness, free of suspended solids, and free of microbial contamination. |
front 3 What are the general water quality characteristics of groundwater supplies | back 3 contains dissolved solids, dissolved gases, high hardness, free of suspended solids, and free of microbial contamination. |
front 4 How can the sustained yield of an aquifer be exceeded | back 4 if a well draws out more water than is replaced, causing subsidence (settling of the ground as water is removed). |
front 5 List the three basic water rights | back 5 Appropriative, prescriptive, and riparian. |
front 6 What is the purpose of a sanitary survey | back 6 determine how much water is available and if it is safe to drink/use. |
front 7 When conducting a sanitary survey, what protective measures should be investigated regarding use of the watershed | back 7 control fishing, boating, landing of airplanes, swimming, wading, ice cutting, and permitting animals on shoreline areas. |
front 8 List the common physical characteristics of water | back 8 water color, turbidity, temperature, taste, and odor. |
front 9 What causes turbidity in water | back 9 the presence of suspended material in water. |
front 10 Chemical analysis of a domestic water supply measures what three general types of chemical concentrations | back 10 inorganic chemicals, organic chemicals, and general mineral constituents. |
front 11 Why are coliform bacteria used to measure the bacteriological quality of water | back 11 they are always present in fecal wastes and outnumber other pathogenic organisms. |
front 12 What tastes/odors are caused by algae | back 12 fishy, aromatic, grassy, septic, musty, and earthy. |
front 13 Increased organic loadings from algal blooms can cause what kinds of water quality problems | back 13 increased color and increase in chlorine demand, leading to increased costs. |
front 14 What is the influence of algal blooms on dissolved oxygen | back 14 DO increases as algae produces it via photosynthesis. |
front 15 What problems are caused by anaerobic conditions in reservoirs | back 15 hydrogen sulfide may be produced by anaerobic bacteria as they consume organic matter. |
front 16 What is the primary purpose of reaeration-destratification programs in domestic water supply reservoirs | back 16 eliminate, control, or minimize negative effects on domestic water quality that occur during periods of thermal stratification and DO depletion. |
front 17 How can water quality be improved by reaeration destratification | back 17 add DO to zones that become anaerobic during thermal stratification. |
front 18 List two basic methods of maintaining/increasing DO in reservoirs when thermal stratification occurs | back 18 destratification through aeration, and adding DO to the hypolimnion (hypolimnetic aeration/oxygenation). |
front 19 What are nonsettleable solids | back 19 also called colloidal matter, bacteria, clay/silt that does
not |
front 20 What happens in the coagulation/flocculation processes | back 20 particulates clump together in coagulation with chemicals and clump further in the flocculation process. |
front 21 What is the primary purpose of flash mixing | back 21 mix chemicals with raw water containing |
front 22 Why are both primary coagulant and coagulant aids used in coagulation | back 22 primary coagulants remove the electrical charge while aids add density and toughness to prevent floc breakdown. |
front 23 List four methods of mixing coagulant chemicals into the plant flow | back 23 hydraulic mixing using flow energy in the system, mechanical mixing, diffusers and grid systems, and pumped blenders |
front 24 Describe the results of inefficient mixing during flocculation | back 24 ineffective collisions and poor flocculation of particulates; may tear the floc apart. |
front 25 What is the minimum recommended detention time for flocculation | back 25 5-20 minutes for direct filtration and 30 minutes for conventional filtration. |
front 26 What is the advantage of vertical flocculators over horizontal flocculators | back 26 they require less maintenance as they eliminate submerged bearings and packings. |
front 27 Why are the compartments in flocculation basins separated by baffles | back 27 prevent short circuiting of water; water following a path may flow too fast, not enough time to settle/react. |
front 28 Why is coagulation-flocculation treatment important to other treatment processes | back 28 for efficacy purposes, reduce THM production, reduce pathogens. |
front 29 What is the most important consideration in coagulation-flocculation process control | back 29 selection of the proper type and amount of coagulant chemicals to be used. |
front 30 Which processes remove suspended solids after the CF process | back 30 sedimentation and filtration. |
front 31 List the typical functions performed by an operator in the normal operation of the CF process | back 31 monitor process performance, evaluate water quality conditions, check and adjust process controls and equipment, and visually inspect facilities. |
front 32 How is the effectiveness of solids removal process normally monitored | back 32 visual observations and laboratory testing. |
front 33 Which lab tests would you use to monitor the CF process | back 33 water quality indicators used to evaluate coagulant dosage and process performance include turbidity, temperature, alkalinity, pH, color, and chlorine demand. |
front 34 What would you look for when visually observing the performance of a CF process | back 34 leaves, twigs, odors, and organic matter. |
front 35 Why do many operators prepare flow v. detention time curves for basins in their plans | back 35 allows for easy selection of stirring times when performing jar tests. |
front 36 What is the goal in setting up a jar test | back 36 see how chemicals chemical doses, mixing times, and other parameters will affect the plant’s performance on a smaller scale. |
front 37 Why should jar test samples have the same temperature as water in the plant | back 37 temperature can affect floc formation; running at different temperatures can provide information on how temperature affects the process. |
front 38 Why are anionic and nonionic polymers used as coagulant aids often prepared as dilute solutions | back 38 dilution prevents a viscous material from being formed. |
front 39 List the four zones into which a typical sedimentation basin can be divided | back 39 Inlet zone, settling zone, sludge zone, outlet zone. |
front 40 What are launders | back 40 sedimentation basin and discharge channels consisting of overflow weir plates and conveying troughs. |
front 41 Three possible shapes for sedimentation basins | back 41 rectangular, circular and square, double deck. |
front 42 List advantages/disadvantages of double deck sedimentation basins | back 42 surface area is doubled, but are more costly and if an issue arises in either deck, the entire operation must be shut down. |
front 43 Why are rectangular basins preferred over circular ones | back 43 less likely to short circuit and particle removal issues. |
front 44 During operation of a solids-contact unit, what items should be of particular concern to the operator | back 44 a uniform sludge blanket is formed and maintained throughout the soldis removal process. |
front 45 How would you calculate the detention time for a sedimentation basin | back 45 dividing the volume of the basin by the flow going into the basin. |
front 46 What problems are caused by reduced effective water depth from excessive sludge buildup | back 46 high flow velocity, sludge scouring, and degradation of process efficiency. |
front 47 Name two kinds of launders used in basin outlets | back 47 V-notch weirs, and orifices in pipes. |
front 48 List two advantages of solids-contact units | back 48 capital and maintenance costs, and volume adjustment of sludge blankets. |
front 49 How can the level of the sludge blanket be determined in solids-contact units | back 49 placing sampling taps at various depths along the wall of the solids-contact reactor. |
front 50 What should be done when a rapid change in turbidity is expected | back 50 early application of an increased chemical dose. |
front 51 How is the proper chemical dose selected when operating a solids-contact unit | back 51 jar testing. |
front 52 List the devices that may be used to provide recirculation in a solids-contact unit | back 52 impeller, turbine, pumping unit, or air injection. |
front 53 How is the percentage of slurry present in the reaction zone determined | back 53 performing a volume over volume test (settled slurry/total sample volume) |
front 54 Under what circumstances are sedimentation basins needed to treat water | back 54 remove suspended solids and reduce load on the filters |
front 55 What is the difference between normal operations and abnormal operations | back 55 normal operations are within operating ranges while abnormal operations are unusual or difficult to handle operations. |
front 56 The actual performance of sedimentation basins depends on what two major factors | back 56 turbidity of the water and temperature of the water. |
front 57 How can an operator determine if sludge lines are free flowing | back 57 if sight glasses are incorporated in the sludge discharge piping. |
front 58 What should be changed if the sludge line plugs frequently | back 58 frequency of sludge removal must be increased. |
front 59 How often should visual observations of sedimentation process performance be conducted | back 59 frequently/day by day. |
front 60 In the routine operation of the sedimentation process, what types of records should be maintained | back 60 influent/effluent turbidity and influent temperature, process production inventory, and process equipment performance. |
front 61 What water quality indicator is used as a rough measure of sedimentation basin process removal efficiency | back 61 measurement of turbidity levels. |
front 62 What problems can be created by a sudden increase in settled water turbidity | back 62 filtration error. |
front 63 What actions might an operator take if the sludge is rising or floating in a sedimentation basin | back 63 observe floc settling characteristics (dispersion, size, settling rate), evaluate process performance, perform jar tests, make changes and verify response to process changes. |
front 64 Why should photographs be taken during shutdown and startup procedures | back 64 provide a visual record of events that may be difficult to illustrate when a basin is full of water. |
front 65 List steps in the shutdown process for a sedimentation basin | back 65 stop flow to basin, install isolation gates, turn off sample pumps and sludge removal, lock out and tag electric switches and equipment, dewater basin, grease and lubricate all gears, sprockets, mechanical parts that were submerged to avoid freezing/breakage. |
front 66 How frequently should turbidity be monitored | back 66 several times per shift. |
front 67 How are sedimentation process water samples obtained for analysis | back 67 immediately taken in clean plastic/glass containers and without contaminants. |
front 68 What items should an operator look for after a sludge pump has been started | back 68 check for noises, vibration, temperature, leaks, suction and discharge pressures. |
front 69 List typical functions performed as part of a sedimentation process preventative maintenance program | back 69 keep motors free of dirt and moisture, ensure good ventilation, check pumps and motors for leaks, noise, vibration, etc, maintain lubrication, inspect alignment of shafts and couplings, check bearings, check proper valve operation, check free flow of sludge in sludge removal collection and discharge systems. |
front 70 What types of safety hazards are associated with sludge removal equipment | back 70 electrical, mechanical, open surface water, valve and pump vaults, sumps. |
front 71 What is the difference between conventional and direct filtration | back 71 conventional filtration involves coagulation, flocculation, and sedimentation, while direct omits sedimentation and flocculation is reduced/omitted as well. |
front 72 List the particle removal mechanisms involved in the filtration process | back 72 sedimentation on media, adsorption, biological action, absorption, and straining. |
front 73 List the four classes of filters | back 73 gravity filtration, pressure filtration, diatomaceous earth,
slow |
front 74 Define garnet | back 74 reddish glassy mineral sands made of silicates (calcium, magnesium, iron, and manganese) |
front 75 What material is used for precoat and body feed operation | back 75 diatomaceous earth. |
front 76 What material is most often used to support granular filter materials | back 76 gravel. |
front 77 What units are commonly used to express filtration rate | back 77 gal/min/ft^2 or L/sec/m^2 |
front 78 What is the major operational difference between sand and dual media filters | back 78 sand filters have light fine grains on the top to stop floc, dual media filters have larger diameter grains in the top layer to stop larger particulates. |
front 79 What two main factors influence the time period before a filter becomes clogged | back 79 amount of suspended solids in the water, and filtration rate. |
front 80 Under what conditions is the filtration process stopped and the filter taken out of service for cleaning/backwashing | back 80 filter clogged, breakthrough occurs, or sufficient time has passed. |
front 81 List four types of surface wash systems for filters | back 81 Baylis, fixed-grid, rotary, and air scour. |
front 82 What aspects of the filtration process are controlled by the filter control system | back 82 flow rates through the filter by maintaining an adequate head above the media surface. |
front 83 What is the primary purpose of using activated carbon as filter media | back 83 remove tastes and odors. |
front 84 What is inline filtration | back 84 addition of filter aids to the filter inlet pipe. |
front 85 What water quality factors affect the floc formation during inline filtration | back 85 variable turbidity and bacterial levels. |
front 86 When is direct filtration used | back 86 when source water is low in turbidity, color, plankton, and coliform organisms. |
front 87 What factors must an operator measure to control the performance of the filtration process on a day to day basis | back 87 turbidity (influent and effluent), and filter performance. |
front 88 What is the most important water quality indicator used to monitor the filtration process | back 88 effluent water turbidity. |
front 89 How can filter effluent turbidity be measured on a continuous basis | back 89 by an in-process turbidity meter. |
front 90 List some of the typical functions performed by operators in the normal operation of the filtration process | back 90 monitor process performance, evualte water quality conditions and make appropriate changes, check and adjust process equipment, backwash filters, evaluate filter media condition, visually inspect facilities. |
front 91 What could cause a sudden increase in head loss through a filter | back 91 lack of depth penetration. |
front 92 How would you change the operation of a filter if there was a sudden increase in head loss through the filter | back 92 adjust filter aid chemical feed rate or reduce filtration rate. |
front 93 What is meant by bumping a filter | back 93 opening backwash valve during a filter run to dislodge trapped solids and increase filter run length. |
front 94 List the type of process calculations an operator is expected to perform | back 94 filter operation, backwashing, water production, and percent of water production used to backwash filters. |
front 95 How are filter backwash rates usually given | back 95 gal/min/ft^2 or L/sec/m^2 of surface area. |
front 96 Calculate the percent of water filtered used for backwashing if a filtration plant uses 0.12M gallons for backwashing during a period when a total of 5M gallons of water was filtered | back 96 2.4 |
front 97 What types of records should be kept when operating a filtration process | back 97 water quality, operation, water production, percent of water production for backwashing, and equipment performance. |
front 98 How would you identify an upset or failure in the filtration/pretreatment process | back 98 abrupt changes in turbidity, pH, alkalinity, TON, temperature, chloring demand/residual, or color. |
front 99 List indicators of abnormal filtration process conditions | back 99 mudballs in filters, media cracking/shrinkage, media boils during backwash, excessive media loss or disturbance, shorter filter runs, uncleanable filters, algae on walls and media. |
front 100 How could you make a quick determination of filtration removal efficiency | back 100 changes of source water quality, pH, and alkalinity. |
front 101 What problems may be encountered during backwash | back 101 mudball formation, filter cracks/shrinkage. |
front 102 How does a filter become air bound | back 102 release of dissolved air in saturated cold water due to a decrease in pressure. |
front 103 Under what conditions may clean filters be put back into service | back 103 when a dirty filter is removed, to decrease filtration rates, or increase production for increased demand. |
front 104 When are filters routinely taken off for backwashing | back 104 when media is clogged, turbidity breakthrough occurs, or water demand is reduced. |
front 105 Why should the surface wash system be activated just before the backwash cycle starts | back 105 aid in breakdown and removal of solids, prevent mudball development. |
front 106 What should be done if a filter will be out of service for a prolonged period | back 106 drain water to avoid algal growth. |
front 107 List types of equipment used in the filtration process | back 107 filter control valves, backwash/surface water pumps, flowmeters and level/pressure gauges, water quality monitors (turbidity meter), process monitors for head loss and water levels, mechanical and electrical filter control systems |
front 108 What should be done before starting a piece of mechanical equipment such as a backwash pump | back 108 be sure it has been serviced and operational status is positively known. |
front 109 What safety hazards may be encountered when working around mechanical equipment | back 109 rotating equipment, energized valves, pumps and other pieces of equipment, chemical spills |
front 110 What is the SWTR definition of surface water | back 110 all water open to the atmosphere and subject to surface runoff. |
front 111 What is the SWTR definition of surface water | back 111 all water open to the atmosphere and subject to surface runoff. |
front 112 Particle counts can be used as a substitute for indicating the potential removal of what two microorganisms that are a threat when found in drinking water | back 112 giardia and cryptosporidium cysts. |
front 113 Particle counters can be used to enhance the performance of which water treatment process | back 113 N/A |
front 114 What is the difference between turbidity meter and particle counter measurements | back 114 N/A |
front 115 What two factors influence the effectiveness of disinfection on microorganisms | back 115 reactions with organics and reducing agents. |
front 116 List chemical agents that have been used for disinfection other than chlorine | back 116 bromine, iodine, ozone, bases. |
front 117 What is a major limitation of the use of ozone | back 117 solubility. |
front 118 How is chlorine dosage determined | back 118 add chlorine needed for chlorine demand and chlorine residual. |
front 119 How is chlorine demand determined | back 119 chlorine does not react any longer with organic/inorganic materials. |
front 120 List two inorganic reducing chemicals with which chlorine reacts rapidly | back 120 hydrogen sulfide and ammonia. |
front 121 How do chlorine gas and hypochlorite influence pH | back 121 chlorine gas lowers pH by forming HCl, hypochlorite raises pH forming hydroxyl ions. |
front 122 How does pH influence the relationship between HCl and OCl- - HCl favors formation of hypochlorus acid, OCl- is formed from HOCl at pH 8.5 or higher. | back 122 N/A |
front 123 What is breakpoint chlorination | back 123 adding chlorine until demand has been satisfied. |
front 124 An operator’s decision to use chloramines depends on what factors | back 124 quality of raw water, plant regulations, operational practices, and distribution system practices. |
front 125 What are the three primary methods by which chloramines are produced | back 125 preammoniation followed by later chlorination, concurrent ammonia and chlorine addition, post chlorination/ammoniation. |
front 126 Why is the applied chlorine to ammonia nitrogen ratio usually greater than the actual chlorine to nitrogen ratio leaving the plant | back 126 chlorine demand will reduce amount of chlorine available from combined residual. |
front 127 Incomplete nitrification causes the production of nitrite, producing what problems in water disinfection | back 127 rapid reduction of free chlorine and interferes with measuring free
chlorine, |
front 128 What actions should an operator take when there is a sudden absence of chlorine residual in the distribution system | back 128 Retesting for chlorine residual, then checking chlorination
equipment, |
front 129 How does the length of chlorine contact time affect the disinfection process | back 129 With good initial mixing the longer the contact time the better the disinfection. |
front 130 How is the efficiency of a disinfectant measured | back 130 Time in minutes of disinfectant’s contact in the water and concentration of the disinfectant residual. |
front 131 List the two most common points of chlorination in a water treatment plant | back 131 Pre chlorination and post chlorination. |
front 132 Under what conditions should waters not be pre chlorinated | back 132 Raw water containing organic precursor compounds and tasting orders when phenolic compounds are present. |
front 133 What are the benefits of pre chlorination | back 133 Control of algae and slime growths, control of mud-ball formation, improved coagulation, reduction of tastes and odors, increased chlorine contact time, and increased safety factor in disinfection of heavily contaminated waters. |
front 134 List the major parts of a typical hypo chlorinator system | back 134 solution, pump/ejector, treated wastewater from plant. |
front 135 What are the two most common methods of feeding hypochlorites to the water being disinfected | back 135 The hypochlorites solution may be pumped directly into the water or
the |
front 136 How is the rate of gas flow in a chlorinator measured | back 136 Through use of a rotameter. |
front 137 What is the primary advantage of vacuum system chlorinators | back 137 Safety. |
front 138 What type of container is commonly used to store hypochlorite | back 138 Plastic containers. |
front 139 How large a supply of hypochlorite should be available | back 139 One week supply |
front 140 What is the purpose of the fusible plug | back 140 Prevent buildup of excessive pressures and the |
front 141 What is removed by the upper and lower valves of ton chlorine tanks | back 141 Upper valve releases chlorine gas, lower valve releases liquid chlorine. |
front 142 When are mouthbit chemical cartridge respirators used | back 142 Only for escape. |
front 143 How can copper tubing be prevented from getting kinks or dirt inside the tubing | back 143 Use of a sling to hold the tubing when disconnecting it from an empty container to prevent the tube from flopping around. |
front 144 Why are one ton tanks placed on their sides with the valves in a vertical position | back 144 So that either chlorine gas or liquid chlorine may be removed. |
front 145 What would you do before attempting to start any chlorination system | back 145 Read the manufacturer’s literature and your plant’s operation and maintenance instructions. |
front 146 What should be the chlorine residual in the most remote part of the distribution system | back 146 0.2 milligrams per liter. |
front 147 Why should a hypo chlorite feed pump be operated in the upper end of its range (at 6 or 7 in a range of 0 to 10) | back 147 So that the strokes or pulses from the pump will be close together. This way, the chlorine will be fed continuously to the water being treated. |
front 148 When starting a gas chlorinator, how is the system checked for chlorine gas leaks | back 148 With a chlorine leak detector. |
front 149 List the steps to follow when shutting down a chlorinator for a long time period | back 149 Have safety equipment available in the event of a chlorine leak,
close chlorine container gas outlet valve, Allow chlorine gas to
completely evacuate the system through the injector. Chlorine gas
pressure gauges will fall to 0PSI on the manifold and the chlorinator.
Close chlorinator gas discharge valve. The chlorinator may remain in
this condition indefinitely and is ready to be plugged back into
surface by reopening the chlorinator discharge valve and the chlorine
gas container valve. Turn off the chlorinator power switch, lock out,
and tag. Secure the chlorinator |
front 150 Normal operation of a chlorinator includes daily inspection of what facilities or areas | back 150 Container storage areas. |
front 151 What is the purpose of evaporators | back 151 Evaporators are used to convert liquid chlorine to gaseous chlorine for use by gas chlorinators. |
front 152 What abnormal conditions could be encountered when operating an evaporator | back 152 The evaporator water level is low. Low water temperature in the evaporator, no chlorine gas flow to the chlorinator. |
front 153 What are possible chlorinator abnormal conditions | back 153 Chlorine leak in the chlorinator, gas pressure is too low less than 20PSI, injector vacuum is too low, low chlorine residual. |
front 154 How can you determine if the chlorine residual analyzer is working properly | back 154 Determine the actual chlorine residual and compare it with the residual reading from the chlorine analyzer. |
front 155 What is the suggested free chlorine residual for treated water | back 155 0.5 to 1.5 mg/L |
front 156 What is the suggested free chlorine residual for the farthest points in the distribution system | back 156 0.2 mg/L |
front 157 How would you determine if you were chlorinating at the breakpoint – | back 157 Increase the chlorine dose rate. |
front 158 If chlorine is escaping from a cylinder, what would you do | back 158 turn the container so that the leaking side is on top |
front 159 How can chlorine leaks around valve stems be stopped | back 159 By closing the valve or tightening the packing gland nut. |
front 160 How can chlorine leaks at the valve discharge outlet be stopped | back 160 Replacing the gaskets or adapter connection. |
front 161 Why should a chlorinators be located in a separate room | back 161 prevent Chlorine gas leaks from damaging equipment and harming personnel. |
front 162 Why is adequate ventilation important in a chlorinator room | back 162 Remove any leaking chlorine gas that would be hazardous to personnel and damaging to equipment. |
front 163 How can chlorination rates be checked against the chlorinator setting | back 163 measuring and controlling chlorine dosage. |
front 164 When and how often should the weights of chlorine containers be recorded | back 164 At the same time every day. |
front 165 What additional equipment is necessary to use an existing
chlorination unit to produce chlorine | back 165 A diaphragm pump, solution tank, mixer, chlorine dioxide generating tower, and electrical controls. |
front 166 What hazards are associated with the handling of sodium chlorite | back 166 It is very combustible around organic compounds. |
front 167 What factors could increase the maintenance record needed on chlorine dioxide generators | back 167 Dirty water, hard water, or wet chlorine. |
front 168 How often should treated water residual chlorine measurements be made | back 168 At least three times per day on small systems and once every two hours on large systems. |
front 169 What methods are used to measure chlorine residual in treated water | back 169 amperometric titration and DPD tests |
front 170 What does an ORP probe measure in a disinfection system | back 170 A direct measure of the disinfecting power of a chlorine residual. |
front 171 What happens to a microorganism when it loses an electron | back 171 They become inactivated and can no longer transmit a disease or reproduce. |
front 172 What maintenance is required on ORP probes | back 172 Cleaning the unit’s sensor once a month. |
front 173 What properties make chlorine gas so hazardous | back 173 Flooring gas is 2 ½ times heavier than air extremely toxic and corrosive in moist atmospheres |
front 174 What type of breathing apparatus is recommended when repairing chlorine leaks | back 174 A self contained breathing apparatus |
front 175 What first aid measures should be taken if a person comes in contact with chlorine gas | back 175 leave the area and remove any clothing that might contain chlorine gas. In extreme cases call 911 then begin treating the victim. |
front 176 What happens when ultraviolet radiation is absorbed by the cells of microorganisms | back 176 It damages the genetic material in such a way that the organisms are no longer able to grow or reproduce |
front 177 What are the three types of electrode type lamps used to produce UV radiation or UV light | back 177 low pressure low intensity, low pressure high intensity, medium pressure high intensity |
front 178 What is a ballast | back 178 A type of transformer that is used to limit the currents to a UV lamp. |
front 179 How is the number of UV banks per channel determined | back 179 The required UV dosage to achieve the target effluent quality |
front 180 How are UV lamps installed when it is necessary to maintain within the water transmission system | back 180 UV lamps can be installed in a closed pressure vessel |
front 181 What kinds of damage can the light from a UV lamp do to operators | back 181 skin burns |
front 182 The UV light intensity that reaches the pathogens in the water is affected by which factors | back 182 The condition of the UV lamps and the quality of the water. |
front 183 The UV unit automatically adjusts UV dose according to which factors | back 183 Based on the received dose, derive from flow and input from the intensity sensors |
front 184 How is the UV dose calculated | back 184 The intensity of the UV radiation and the contact time |
front 185 Why do operaters need to periodically observe the UV wiping process | back 185 To ensure proper operation of the wiping action of a bank and the proper wiping cycle |
front 186 What’s preliminary steps should be followed when shutting down or starting up a UV disinfection process | back 186 Applying ahead check switches clean units prepare equipment and set |
front 187 How can UV light bulbs be cleaned | back 187 in an acid bath in a cleaning tank |
front 188 Why must operators monitor the lamp output intensity | back 188 UV lamp burn time |
front 189 What influent and effluent characteristics must be monitored | back 189 to ensure Adequate disinfection is performed by the UV lamps |
front 190 Why do UV systems require extensive alarm systems | back 190 to ensure continuous complete disinfection of the water being treated |
front 191 What tasks are included in the routine maintenance of UV disinfection systems | back 191 Cleaning the quartz sleeves and changing the lamps |
front 192 How often should quartz sleeves be cleaned | back 192 Will depend on the quality of the water being treated and the treatment chemicals used before disinfection |
front 193 What factors influence the service life of UV lamps | back 193 the the level of suspended solids in the water to be disinfected, the frequency of on/off cycles, and the operating temperature of the lamp electrodes. |
front 194 How can operators determine the proper way to dispose of used UV lamps | back 194 Contacting the appropriate Regulatory agency to determine the proper way to dispose of used UV lamps |
front 195 What factors influence the effectiveness of ozone disinfection | back 195 The susceptibility of the target organisms, the contact time, and the concentration of the ozone. |
front 196 What are the key process control guidelines for ozone disinfection | back 196 dose, mixing, and contact time. |
front 197 Why is ozone generated on site | back 197 it is very unstable and decomposes to elemental oxygen in a short time after generation. |
front 198 List the problems that can be created by corrosive waters | back 198 Rusty water stained laundry bad taste and internal corrosion of pipes |
front 199 What is an electrochemical reaction | back 199 Chemical change is produced by electricity or the production of electricity by chemical changes |
front 200 What happens to an iron water pipe when the pipe is connected to a copper pipe | back 200 The iron will corrode if water contains dissolved oxygen and the copper will be protected. |
front 201 What is the dezincification of brass | back 201 when brass corrodes leaving behind copper |
front 202 What happens when copper and lead solder are in contact | back 202 The lead becomes the anode and will corrode in preference to the copper |
front 203 What is a dangerous corrosion inhibitor | back 203 Inhibitors that act on the anode reaction because if there is not enough inhibitor added severe pitting will result and corrosion will be worse than if none had been added. |
front 204 What will happen if a copper service line is connected to a steel water main | back 204 corrosion will occur at the anode. |
front 205 What effect of stray current corrosion may be evident to homeowners | back 205 When pitting penetrates fixtures or pipes resulting in leaks. |
front 206 What causes erosion corrosion in copper tubing | back 206 High velocities |
front 207 List the chemical factors that influence corrosion | back 207 PH alkalinity chlorine residual levels of dissolved solids dissolved gases and the types and concentrations of various minerals present in the water |
front 208 Why does water with a higher dissolved solids content have a greater potential for corrosion | back 208 Solids dissolved in water are present as ions and increase salt content of the water increasing conductivity |
front 209 What is the impact of calcium carbonate on corrosion | back 209 It acts as a corrosion control measure |
front 210 What is the most common type of corrosion cell | back 210 Oxygen concentration cell |
front 211 Where can an oxygen concentration cell be started | back 211 In the dead end of a water main |
front 212 How can pits be started on a metallic surface underwater | back 212 Anything that will shield the metal surface from dissolved oxygen in the water |
front 213 What is a tubercle | back 213 A Mound of iron rust |
front 214 Why is corrosion of water system facilities a public health concern | back 214 To protect the public from the harmful effects of lead copper or other toxic metals in drinking water |
front 215 How can corrosion rates be measured | back 215 By inserting special steel specimens called coupons in the water mains. After a period of time the coupons are removed and the loss of weight and nature of corrosion damage are measured. |
front 216 How can leaks in pipes be detected | back 216 The observation of wet spots above a pipeline |
front 217 How can you detect a film of calcium carbonate that is too thin to see | back 217 when they drop of dilute hydrochloric acid is placed on an obvious cathodic area |
front 218 What does a loss of dissolved oxygen in the water flowing in a distribution system indicate | back 218 N/A |
front 219 What toxic metals may enter drinking waters from the customer’s
plumbing due to corrosive | back 219 N/A |
front 220 When is a water considered stable | back 220 When it is just saturated with calcium carbonate |
front 221 How can water be tested to determine if it is under saturated or supersaturated with calcium carbonate | back 221 The CCPP or the Langelier index |
front 222 The Langelier index is determined by what equation | back 222 Langelier index = pH - pHs |
front 223 What is the meaning of pHs | back 223 pH at which water having the same alkalinity and calcium content is just saturated with calcium carbonate |
front 224 Why do some waters not have a meaningful pHs value | back 224 They have a low calcium content and alkalinity |
front 225 What do rusty or red water complaints indicate | back 225 Where they are occurring and how they can be corrected |
front 226 How can the corrosivity of a water be reduced | back 226 Treating the water with chemicals so that it is saturated or slightly supersaturated with calcium carbonate |
front 227 What chemicals may be added to waters to reduce the corrosivity | back 227 Quicklime, hydrated lime, soda ash, and caustic soda |
front 228 What chemicals may be required for corrosion control if the product of calcium hardness multiplied by the alkalinity Is less than 1000 | back 228 Calcium and carbonate |
front 229 What chemicals will be required for corrosion control if the product of calcium hardness multiplied by the alkalinity is greater than 5000 | back 229 caustic soda or lime |
front 230 How can the proper chemical dose be determined to produce water that is just saturated with calcium carbonate | back 230 May be determined graphically or by a trial and error calculation that is practical only with the help of a computer |
front 231 List one advantage and one limitation of using zinc compounds instead of lime or caustic for corrosion control | back 231 scaling is reduced (water hardness) |
front 232 Where is the application of cathodic protection practical in water treatment plants | back 232 reduce corrosion of metal to water or soil. |
front 233 What is the best measure of the corrosivity of soil | back 233 soil resistivity measured using a soil resistance meter |
front 234 How can electrolysis of water mains be caused by other utilities | back 234 stray currents generated by cathodic protection installed by other utilities. |
front 235 How can internal pipe corrosion be detected and controlled | back 235 detected through rusty water complaints and examining the pipes for pitting/tubercles/corrosion evidence, must be treated to achieve calcium carbonate saturation. |
front 236 How can external pipe corrosion be detected and controlled | back 236 indicate by pinhole leaks or rust on outside of pipes, cathodic protection can suffice, or have the pipe replaced with PVC/plastic pipes, cement coated line |
front 237 List the important elements of the 1991 lead and copper rule | back 237 MCL goals, monitor lead, treatments for lead/copper, public notification and education, utilities record keeping and reporting, variances and exemptions regulations and compliance schedules based on population size. |
front 238 What is the definition of an action level in the lead and copper rule | back 238 value measured in the 90 th percentile at the consumer’s tap |
front 239 What are the accepted potable water corrosion control treatments | back 239 N/A |
front 240 How do chemical inhibitors control lead and copper in water distribution systems | back 240 providing s coating that prevents corrosion |
front 241 How must a utility attempt to educate the public if it fails to meet the lead action level | back 241 EPA developed public education program must be initiated |
front 242 How frequently may taste and odor problems occur at a water treatment plant | back 242 They may occur locally on a persistent seasonal occasional or infrequent basis |
front 243 What are the most common types of water quality complaints received by a water utility | back 243 Taste odor and colored water |
front 244 What is the most damaging effect of problems for a water utility | back 244 The loss of public confidence in the water utilities ability to provide a safe high quality water |
front 245 List the major causes of tastes and odors in a water system | back 245 geosmin, MIB, chlorine, chloramines, aldehydes, phenols and chlorophenols |
front 246 Where could conditions develop in a water system | back 246 Algal blooms and source waters disinfectants used and the water distribution system |
front 247 Which two compounds can produce earthy and musty odors in the water | back 247 geosmin and MIB |
front 248 Which inorganic chloramine causes the least odor problems in treated water | back 248 Trichloramine |
front 249 Name two groups of bacteria that are known to produce compounds in water | back 249 actinomycetes |
front 250 What common blue green algae are associated with odors ranging from earthy musty to septic | back 250 anabaena, aphanizomenon, oscillatoria, microcystis |
front 251 What are the two general ways in which microbial populations can contribute to unpleasant tastes and odors in water | back 251 Metabolic byproducts and cellular material of common aquatic microorganisms |
front 252 Why does water sometimes have better qualities before treatments than after treatment | back 252 When cells die they rupture and cellular material is released into the water |
front 253 When should the application of an algicide be considered | back 253 When the dominant algae is identified as a producer, when algae is not a dominant organism in the population, And sensory or chemical analysis indicates an increase in the order of the water |
front 254 What types of minerals in runoff waters can lead to oxygen depletion | back 254 Nitrogen and phosphorus |
front 255 How can the nutrient levels in a water supply be increased | back 255 reuse of sludge lagoons |
front 256 What causes the diurnal dissolved oxygen cycle | back 256 Algae that produce and consume oxygen |
front 257 What factors can cause contamination of a water supply by septic tank and leach field systems in rural areas and in resort and vacation developments | back 257 they may be located too close to rivers and improperly set |
front 258 How can industrial waste discharges cause taste and odor problems | back 258 Directly adding odorous compounds such as phenols and aromatic hydrocarbons to the water and adding nutrients that result in causing algal blooms |
front 259 What are the sources of most chemical spills | back 259 The result of accidents at industrial plants chemical storage facilities or during transportation |
front 260 Why are many municipal water intake facilities located upstream from major agricultural areas | back 260 To avoid possible termination of the water supply by fertilizers microbial contaminants pesticides and herbicides |
front 261 List some sources of agricultural wastes that may cause problems in a water supply | back 261 animal wastes, Previously applied fertilizers pesticides herbicides and the spreading agent used to apply them |
front 262 How do debris and sludge cause tastes and odors | back 262 microorganisms grow in the organic material |
front 263 What parts of the plants are likely locations for algal colonization | back 263 In the sedimentation basin and filter walls and weirs |
front 264 What are the most likely sources for the development of tastes and odors | back 264 Any part of the system that are used to store transport or regulate untreated water may provide a suitable habitat for organisms that produce objectionable tastes and odors due to an absence of chlorine residual |
front 265 What kind of survey is used to identify the sources of tastes and odors in raw water | back 265 sanitary survey |
front 266 How do the chemicals used in a water treatment plant interfere with a search for the source of tastes and odors | back 266 Treatment chemicals such as chlorine and powdered activated carbon tend to mask any changes in quality that may be occurring within the plant |
front 267 Where are the potential sources of tastes and odors within a water treatment plant | back 267 Algal growth due to poor housekeeping practices |
front 268 What are the main causes of tastes and odors in the distribution system | back 268 Microbiological activity, disinfection residuals and their byproducts, organic or mineral compounds from system materials, and external contaminants from cross connections |
front 269 What types of complaints would alert you to the potential of a cross connection | back 269 Complaints about a musty septic or other strange odor in the water |
front 270 Which two components should be incorporated into a taste and odor monitoring program | back 270 Routine counting and identification of source water algal populations and attached algae in the |
front 271 plant, and sensory analysis such as a taste threshold test of source and distribution system waters and plant profiles when needed | back 271 N/A |
front 272 What happens when settled sledges and other debris are allowed to accumulate in the bottoms of channels and tanks in a water treatment plant | back 272 these areas will become septic and impart a foul taste and odor to the water |
front 273 When are portions of water treatment plants usually taken out of service for inspection and cleaning while the remainder of the plant continues to operate | back 273 During the winter months when flows are lower and a full plant capacity is not needed to meet water demands |
front 274 Why should treatment equipment be capable of operating properly at all times | back 274 The |
front 275 What sensory method uses a trained panel to identify tastes and odors in both the treatment process and distribution system | back 275 The taste threshold test |
front 276 List the two broad categories of taste and odor treatment methods | back 276 Removal and destruction |
front 277 How does the use of chlorine influence taste and odors when water contains algae | back 277 It leads to an increase in odor to to the destruction of algal cells by chlorine |
front 278 How can tastes and odors caused by algae be removed most economically in a water treatment plant | back 278 Through the use of improved coagulation |
front 279 Aeration is best suited for treating what type of taste and odor problems | back 279 reduced inorganic compounds such as ferrous iron or manganous manganese |
front 280 What are the two basic ways that aeration systems can be designed | back 280 passing water through the air or passing air through the water |
front 281 What types of odors can often be decreased significantly by chlorination | back 281 N/A |
front 282 Under what circumstances might the use of chlorine be the wrong treatment for a taste and odor problem | back 282 N/A |
front 283 How would you respond to a permanganate overdose | back 283 Adding powdered activated carbon or increasing the pH |
front 284 Why must permanganate storage facilities be dry and well ventilated | back 284 Moisture can cause caking of the material |
front 285 Why are adequate permanganate dust control and ventilation importance for equipment protection | back 285 Prevents breathing in of the dust which is irritating to the eyes
mucous |
front 286 Why should laboratory and pilot scale testing of the effectiveness of ozonization as a taste and odor control process be conducted before full scale installation | back 286 Due to the specialized equipment requirements |
front 287 Why must chlorine dioxide be generated on site | back 287 it is highly unstable |
front 288 What types of taste and odor producing wastes have been treated successfully by using chlorine dioxide | back 288 industrial pollution |
front 289 What two forms of activated carbon are used in water treatment | back 289 Powdered activated carbon or granular activated carbon |
front 290 What terms are used to describe the adsorptive capacities or ratings of activated carbons | back 290 The basis of a phenol number or an iodine number |
front 291 Why should PAC be applied at the plant flash mixing facilities | back 291 Carbon must contact the material to be removed for adsorption to occur |
front 292 What would you do if a caked layer of carbon starts to form on the surface of the water in the slurry tank | back 292 The cake can be broken up using breaker bars or wooden paddles |
front 293 What precautions must operators take because powdered activated carbon is so abrasive | back 293 Equipment used to feed PAC often requires more frequent inspection
cleaning and |
front 294 What adjustments would you make if PAC tends to cake on the surface of the filters | back 294 adjustments to improve PAC removal in the settling process |
front 295 How can carbon penetration through a filter be detected | back 295 collect a one liter sample of filter effluent and filter it through a 0.45 picometer membrane filter |
front 296 What is empty bed contact time in a granular activated carbon filter | back 296 The time that the water is actually in the filter bed |
front 297 What information should be recorded on a water quality complaint form | back 297 name and address of complaints location and description of complaint comments of field investigator response actions and conclusions |
front 298 How should operators be kept informed of taste and odor problems | back 298 Through a standard notification procedure for complaints |
front 299 What tests can operators conduct to identify problems before they reach the consumer | back 299 Routine testing of raw and finished water for quality |
front 300 What factors could cause taste and odor complaints in the local area of a distribution system- | back 300 N/A |
front 301 Which locations in a water supply system might contribute problem | back 301 Raw water source storage facilities raw water transmission systems and facilities at a treatment plant |
front 302 Why is it important to write out an updated list of options available for treating problems | back 302 N/A |
front 303 What two analysis can be used as an early warning system for taste and odor events | back 303 Routine monitoring of algal populations in conjunction with the use of sensory analysis in the form of tastes threshold test |
front 304 List the five types of primary contaminants considered to be of public health importance | back 304 Inorganic contaminants, Organic contaminants, turbidity, microbial contaminants, and radiological contaminants |
front 305 What criteria must be met before EPA selects a contaminant for regulation | back 305 The contaminants may have an adverse effect on the health of the people, it is known to occur or there’s a high chance it will occur in PWS often enough and at levels of public health concern, And regulation of the contaminants presents a meaningful opportunity for health risk reductions for people served by PWS |
front 306 What is the purpose of a consumer confidence report rule | back 306 To improve public Health Protection by providing educational material to allow consumers to make educated decisions regarding any potential health risks pertaining to the quality treatment and management of their drinking water supply |
front 307 Why are treatment technique requirements also referred to as primary standards rather than as MCLs | back 307 Testing for certain contaminants can be expensive requiring specific treatment |
front 308 Why is arsenic listed as a primary contaminant | back 308 N/A |
front 309 Why is nitrate in drinking water above the national standard of 10 mg/L considered an immediate threat to public health | back 309 it causes blue baby syndrome |
front 310 What is the purpose of the TCR | back 310 It is the limit of total coliforms in drinking water |
front 311 What is the most basic test for bacterial contamination of a water supply | back 311 test for total coliform bacteria |
front 312 What does the final RTRC establish | back 312 MCL for E. Coli |
front 313 What Organism is most implicated in US waterborne disease outbreaks | back 313 Giardia lamblia |
front 314 How do regulation treatments techniques ensure that harmful organisms are treated | back 314 N/A |
front 315 Why substitute chlorine residual testing for some of the bacteriological testing | back 315 It could give a quicker indication of the condition of the system |
front 316 What is often the most corrosive chemical found in a water plant | back 316 N/A |
front 317 What is one important safety precaution that should be followed at a water treatment plant | back 317 N/A |
front 318 What are the symptoms of fluoride poisoning | back 318 N/A |
front 319 What is the first aid procedure for skin contact with fluoride | back 319 N/A |
front 320 What special training must be given to all operators who handle fluoride compounds | back 320 N/A |
front 321 List the compounds most commonly used to fluoridate water | back 321 N/A |
front 322 List the compounds most commonly used to fluoridate water | back 322 N/A |
front 323 Which is the easiest fluoridation chemical to feed | back 323 N/A |
front 324 List examples of solution feeders for liquid fluoridation chemicals | back 324 N/A |
front 325 What important aspects should be incorporated into the design of a water treatment plant | back 325 N/A |
front 326 Why is sodium silicofluoride not recommended to feed through a saturator | back 326 N/A |
front 327 What is a saturator | back 327 N/A |
front 328 Describe a downflow/upflow saturator | back 328 N/A |
front 329 How can you see the level of undissolved sodium fluoride in an upflow saturator | back 329 N/A |
front 330 List the types of alarms at a fluoridation plant | back 330 N/A |
front 331 List the different parts of a small hydrofluosilicic acid system | back 331 N/A |
front 332 Why should an operator avoid injecting solution into the top of a small hydrofluosilicic acid system pipe | back 332 N/A |
front 333 What type of feeding system is typically found in a large hydrofluosilicic acid system | back 333 N/A |
front 334 Why should hydrofluosilicic acid storage tanks made of plastic be housed in enclosures | back 334 N/A |
front 335 What is one result of using a closed loop control system in an unattended plant using a fluoride analyzer as one of the controls | back 335 N/A |
front 336 When performing the final equipment checkup, what must the operator be certain of | back 336 N/A |
front 337 When reviewing fluoride feeding system designs and specifications, what should the operator check | back 337 N/A |
front 338 Why must corrosion resistant drop pans and drains be provided with a fluoride feeding system | back 338 N/A |
front 339 Why use alarms with a fluoride feeding system | back 339 N/A |
front 340 Why must the proper position for all valves be determined in the industrial feeder startup procedure | back 340 N/A |
front 341 Why record the amount of chemical left in the storage bin | back 341 N/A |
front 342 After a plant shutdown, which meter provides equipment information | back 342 N/A |
front 343 What benefits do the equipment manufacturer’s manuals for procedures provide | back 343 N/A |
front 344 What are the benefits of overfeeding chemicals | back 344 N/A |
front 345 Why should fluoridation equipment be cleaned out of the equipment is going to be shut down for an extended length of time | back 345 N/A |
front 346 How can fluoride dust be removed from gears | back 346 N/A |
front 347 During maintenance of fluoridation equipment, how concerned should you be about checking the feed rate by catching a given amount of fluoride over time | back 347 N/A |