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Illinois Class D Water License Exam|
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Two Towers are both 125 feet high, when full, contain 122 feet of water. Tower 1 holds 150,000 gallons. Tower 2 holds 500,000 gallons. Each has a pressure gauge at the base. Which will register the most pressure in psi? Both will be equal If the water level in tower 1 is 118 feet what will the pressure reading be at the base 51.1 psi What is the definition of potable water Water that does not contain objectable pollution, contamination, or infective agents and is considered safe for drinking What is the first item used when installing a service line to a customer? Corporation stop If a meter to a residence is located in the basement what should be located between the water main and the house
curb stop A 5/8" x 3/4" water meter serves a residence. Over a period of years the meter __________ in recording actual water used Decreases To isolate part of a distribution system what type of valve is commonly used? Gate valve Trihalomethanes (THMs) are caused by? Reaction of chlorinated water with numeric materials found in surface water sources The longer the contact time water and chlorine residuals enjoy the ________ the THM level will probably be Higher THM's should be eliminated from finished water because they cause? Cancer The maximum contaminant level for THM's is? .080 mg/l
A boil order should be issued for? Until further notice Upon the issuance of a boil order the IEPA regional office should be notified of the order because ________________? It's a state regulation The "C" factor of a pipe is _______________? The smoothness of the interior of a pipe The higher the "C" factor of a pipe the _____________ the pipe and the greater the carrying capacity of the pipe Smoother A distribution system that is "looped" instead of having dead ends will help prevent Tastes and odors, "dirty" water, and chlorine depletion Chlorine tablets (calcium hypochlorite) should be used for the disinfection of newly installed water main. These tablets should be ________________ Glued to the top of each section
What is the definition of a water main? Any line that passes one property to reach another parcel of property What is the minimum size of a water main required by the IEPA 4 inches in diameter Is a construction permit from the IEPA permit section required for the installation of a water main? Yes Is a construction permit from the IEPA permit section required for the installation of a water service? No A three-quarter inch service line is tapped on a water main. The corporation stop should be installed__________________ At an angle between the top and side of the main A 6 inch PVC Watermain is installed what should be installed at the end of the main Concrete thrusting block
Trees Three waterborne diseases are? Typhoid, infectious hepatitis, and cholera 9,500 gallons too million gallons per day (MGD) .0095 MGD 98,000 gallons too million gallons per day (MGD) .098 MGD 678,000 gallons too million gallons per day (MGD) .678 MGD 1,245,000 gallons too million gallons per day (MGD) 1.245 MGD .895 MGD too gallons per day 895,000 gallons 2.20 MGD too gallons per day 2,200,000 gallons .019 MGD too gallons per day
19,000 gallons .999 MGD too gallons per day 999,000 gallons How much pressure (in psi) does 1 foot of elevation offer? 2.31 psi Velocity of flow in a water main is expressed in? Beat per second A public water supply purchases 4,500,000 gallons of water from a parent supply in a 30 day period in the same period the public water supply sells 3,900, gallons of water to its customers. What is the amount in gallons of unaccounted for water? What is the percentage of an accounted for water? 600,000 gallons, 13.3% What is the industry standard for acceptable water loss in a public water supply? 10% or less If the pH of a water sample is below seven units it is considered? Acidic
High level of lead and potable water may cause? Mental impairment in children and infants What is the required range of fluoride in mg/l to be in compliance with Illinois Department of public health regulations? .7 to 1.2 mg/l Bacti samples show the absence or presence of coliform. If present the sample contains? Animal and human feces The number of bacti. samples collected in a public water supply distribution system is based on? The population at the supply services Routine bacti. samples are collected on __________ faces at a water supply which buys its water or uses a groundwater source not under the influence of surface water. Monthly What type of test is commonly used for testing fluoride levels?
SPADNS Test What type of test is most commonly used for testing chlorine residuals in a small system or in a distribution system DPD Test Sodium thiosulfate is added to a bacti sample bottle to? Remove any chlorine residual from the sample Bacti. Sample bottle should be? Build completely so no errors present in the bottle after the cap has been replaced To collect bacti. Sample The collector must be? Trained in the proper collection procedures When collecting a bacti. Sample The lit of the sample bottle should be Help bottom down with your fingers on the outside of the rim Bacti. Samples must be analyzed no later than___________ hours after collection 30 Testing for THM's can be performed By the IEPA lab or certain private certified labs
What is the percentage of available chlorine and chlorine gas 100% What is the percentage of available chlorine in calcium hypochlorite 65 to 70 % What is the percentage of available chlorine and sodium hypochlorite 10 to 15% If an operator has total chlorine residual of 1.6 mg/L and the sample has a free chlorine residual of. 9 mg/l what was the chlorine demand in the sample water? .7 mg/l If calcium hypochlorite and oily rags are allowed to come into contact with each other what will occur? Ignition and flash fire will occur When collecting a bacti. Sample The water should be collected after the Fossett has run for at least? A period long enough to adequately flush out the service line to the main
Poly-pigging of a water main forms what purpose? Disinfected the water main, seals the inside of the main with a smooth coding, both, or neither? Neither If a small public water supply pumps 3,000,000 gallons of water in a 30 day period. It's expenses total $8770. How much does it cost this public water supply to produce 1000 gallons of water? And is this, compared to the national average, considered high? $2.92 per thousand gallons. And yes it is a high cost An elevator water tank sits on a bluff overlooking a river valley. The water level in this tank is 144 feet above the base of the tower. A part of the distribution system serves homes along the banks of the river. These homes are 102 feet lower than the base of the water tower. What is the average system pressure in psi at these homes 106.5 psi If a home has a higher pressure than 80 psi what should they install? A pressure reducing valve on their service lines
It allows air to enter well during drawdown to prevent vacuum conditions, vents excess air during well recovery Sounding tube Permits insertions of water lever measuring device device, also used to add cleaning agents Gravel tube Permits operator to see level of gravel and add gravel as necessary Pump pedestal Supports the weight of the pumping unit Pump motor base seal Provides water tight seal between the motor base and the concrete support pedestal Sampling taps Permits sampling if pumped water Air-release vacuum breaker valve Permits discharge of air in column pipe during start up and admits air during shutdown
Valve pump blowoff Used to remove first water pumped at start up Air line water level measuring device Permits measurement of water level by mean of air pressure measurements What is the purpose of a check valve? Acts as an automatic shut off valve when a pump stops, acts to keep water that's has already entered the system from flowing back into the well casing, and helps prevent system pressure from decreasing due to backsiphonage. If a well pump motor is wired backwards the well pump will ______________? Still pump some water A water plant has a lineshaft well. The operator replaces the packing in the packing gland on the motor. After the packing has been replaced there should be ___________? A small trickle of water when the pump is operating. A pump housing which obtains its power from a side shaft electric motor airlocks. The pump itself is extremely hot to touch. How do you correct this problem?
Electrical thawing A meter located in a mirror pit freezes in winter. what is the best option that the operator has in thawing the line Use hot air heated obtained from the tailpipe of a vehicle What is the minimum flow velocity that hydrant should be flushed to adequately flush the line 100 gallons/minute Fire hydrants in Eleanor Maine are of the dry barrel type. Why does a dry barrel hydrant have to be completely opened when operating To get the maximum flow from the hydrant and to run the water from flowing from the weep hole during use which can saturate the drainfield. The minimum vertical gap in an air gap should never be less than________________? Twice the diameter of the discharge pipe All water towers, standpipes, and other types of vessels which store potable water are required to be airtight?
No Performing a water audit can be beneficial to a public water supply by ______________? Reducing water losses, improving the supplies financial status, and increasing the operators knowledge of the system.
