Irrigation System Design and Components, Exams of Water and Wastewater Engineering

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Texas Irrigator License

2024 - 2025 Final Exam Comprehensive

Review Questions and Answers

100%Pass

David Mungai [Date] [Course title]

Texas Irrigator License 2024 - 2025

Final Exam Comprehensive Review

Questions and Answers 100%Pass

Gear rotor model B Spray with X nozzle Spray with Y nozzle Spray with Z nozzle 1" valve model Q Backflow device

Controller Legend To convert psi to feet Multiply by 2. To convert feet to psi Multiply by 0.433 psi Precipitation Rate Formula GPM (Full Circle Head) X 96. -------------- = PR Head Spacing X Row Spacing (Divide) Precipitation Rate for Drip GPH (one emitter) X 231 ------------ = PR Head Spacing (inches) X Row Spacing (inches) Runtime Formula I x 60 RT ----=Runtime PR

Calculating Drip Flow Zone Total Linear feet of drip /emitter spacing x GPH of emitter/ 60 = GPM for that zone Or DMDMD Slope formula Rise S = ----------- Run Triangular Head Spacing Multiply spacing by .866 to get row spacing Efficiency of System Example if 50% efficiency with 1.12 Precipitation rate Divide 1.12 by .50 to get 2.3/PR Design Pressure DP = = Recommended head pressure + total losses Actual Head Pressure AHP == Static Pressure - Total losses D - DIVIDE THE FIRST STEP TELLS YOU HOW MAY ROWS.....DIVIDE THE WIDTH BY EMITTER SPACING IN FEET (EX; 18" = 1. FEET) ALWAYS ADD 1 M -MULTIPLY THIS STEP TELLS YOU HOW MANY TOTAL FEET...MULTIPLY THE TOTAL ROWS BY THE LENGTH D - DIVIDE THIS STEP TELLS YOU HOW MANY TOTAL EMITTERS..DIVIDE THE TOTAL LENGTH BY THE EMITTER SPACING IN FEET M -MULTIPLY THIS STEP TELLS YOU HOW MANY TOTAL GALLONS PER HOUR..MULTIPLY THE TOTAL EMITTERS BY THE GPH GIVEN FOR EACH EMITTER D - DIVIDE

RP

If there is an on-site sewage facility on site, which backflow is approved? RP If major Maintenance has to be performed,which backflow device has to be properly installed prior to the repair work being performed? An approved backflow device If including a master valve,where does it have to be installed? Downstream from the PVB,DCA,or RP Which devices have to be tested upon installation and annually? Devices used in applications designated as health hazards Which backflow device has to be tested upon installation? All Backflow devices If a DCA is installed below ground,what device is required? A Y-Strainer installed on inlet side of the DCA If there is an additional water source supplying water to a system being supplied by potable water supply,what device has to be used on with the potable water supply? RP What device cannot be used when there is health hazard? DCA An AVB and PVB can be used in health hazard situations,if the following conditions are not present: Backpressure,There is pump downstream,Chemicals added An Atmospheric Vacuum Breaker Has to be installed 6'' higher than the highest head or outlet in the retracted position,will not handle constant pressure,and will stop backsiphonage What is the unwanted reversal of water flow in an irrigation system? Backflow A cross connection is any actual or potential connection between a potable water supply and:

Any source that has the possibility to introduce polluted or contaminated water back into the potable water that is supplying it Backsiphonage is caused by? Negative or sub-atmospheric pressure Backsiphonage can be caused by: A break in the City Main or The fire department using water from the city fire hydrant to put out a fire.. If the pressure in the sprinkler system(or downstream side)exceeds the pressure in the supply side,what phenomenon can occur? Backpressure What can cause backpressure? Gravity or a pump How many total ways are there to protect against backpressure and/or backsiphonage? 5 total What is the unobstructed vertical distance through free atmosphere between the lowest point of a water supply outlet and the flood level rim of the fixture or assembly into which the outlet discharges? An air gap The vertical,physical separations,of an air gap, must be: At least twice the diameter of the water supply outlet,but never less than 1 inch What is typical example of an air gap? Kitchen sink

GPM

When using drip irrigation,the water volume of individual drip emitters is generally expressed in: GPH If the plant watering requirement is .5 for a week,precipitation rate is .75,how many minutes of watering will be needed per week? .5 divided .75 x60=40minutes per week The science of applying the required amount of water to promote or maintain the healthy growth of plant material or turf is: Landscape irrigation What is required upon completion of an irrigation? Final walkthru,, Maintenance checklist, A permanent sticker affixed to the controller,An as-built plan...ALL OF THE ABOVE Upon completion of an irrigation system,the irrigation contractor must furnish the owner with: A written warranty covering materials and labor When two,or more,valves are located in the same location or valve box,it is referred to as: A Manifold The TECQ refers to: Texas Commission on Environmental Quality A licenced irrigator can: Sell,design,consult regarding installs,maintenance,alterations,repairs,services What more can a licensed irrigator do than a licensed technician? Sell,design,and consult Sprinkler heads cannot be placed closer to the hardscape than: 4 inches

What is the minimum distance of turf(between the street and the side walk)that you can use above-ground spray emmission devices: 48 inches An irrigator is required to maintain records of irrigation installations for a period of: 3 years A licensed irrigator inspector cannot engage in irrigation services that include: Selling,Designing,Installing,Repairing/ All the above Landscape irrigation,as we know it,has been around since: The turn of the 20th century The issue of top priority in irrigation today is: Water conservation The shortage of water is the result of: Water being a fixed resource Pressure compensating devices help save water because they: Help eliminate misting or fogging at the sprinkler heads Water conservation(with irrigators)starts with: A great design For a irrigation system to work,actual head pressure has to be:

Slow application rates expressed in GPH are usually referring to what type of irrigation: Drip irrigation Water in motion is: Dynamic water Water at rest is: Static water To gain .866 PSI,your piping would have: Elevation loss of two feet An loss of .433 PSI is the result of: An piping elevation gain of 1 foot What is an emitter? A small mechanical device used to limit water flow to a very low drip or trickle What happens when water flows through the irrigation components? You encounter friction loss as water flows through all piping and irrigation components Waste water, such as from bath,sink,or washing machines,is called: Greywater

A permanent assembly of irrigation components for the purpose of watering the landscape or for the purpose of dust reduction or erosion control is: An irrigation system A method of maintaining a constant discharge pressure regardless of inlet pressure is called: Pressure compensating A motorized device which creates,or boost pressure,is: A pump PVC represents what type of irrigation piping? Poly vinyl chloride The reuse of water that has been used previously for some other purpose is called: Reclaimed or recycled water A drawing of an installed irrigation system showing major components is: Called an as-built plan Run-off can occur when: The precipitation rate exceeds the infiltration rate of the soil Calculating and managing the time and amount of water to apply to the plant material is referred to as: Scheduling

Sprinkler heads that are more suitable to larger,more open landscape areas are: Rotary heads To get matched precipitation, with gear-driven rotary heads ,you must select and match the correct nozzles from the: Nozzle tree Bubblers would need to be installed in an area that is: Level and bordered The slow application of water directly to the root zone,using very low pressure,is referred to as: Drip irrigation A filter,flush valve,and pressure regulator would typically be used with: Drip irrigation What is not an advantage of drip irrigation? Checking for proper operation A drain valve will help protect the irrigation system from: Pipe freezing and breaking What does a check valve do? Allows water to go in only one direction PVC pipe: Is not UV resistant What is PVC pipe that is classified by its working pressure? Class pipe What are some characteristics of poly pipe?

UV resistant / Flexible/ Used with drip irrigation/ Connected with insert fittings (ALL the above) What types of copper pipe are available and which has the heaviest wall thickness? K,L,and M with K having the heaviest wall thickness How is the smoothness on the inside of the pipe rated? C-Factor What device would be used if the pressure in a system is to high? Pressure regulator What are three accepted means to control pressure in the heads? Pressure regulator,Pressure compensating device, and the valve flow control ET based controllers regulate the irrigation schedule based on what? Evaporation, Transpiration, Evapotranspiration, (A,B,and C)answer If your watering 30 minutes three times a week and are having a run-off problem, how can this be solved? Water 10 minutes, three times a day, three times a week To save water and prevent liabilty issue to possible injuries from accidents involving ice,what type of sensor would you use? Freeze

the solvent(D)Wiping off the excess solvent Answer (All of the Above ) What is/are some characteristics of an isolation valve? (A)Allows for repairs without shutting the water off to the building (B) Typically,it is a gate or ball valve (C)It serves as a manual shut-off valve for entire irrigation system (D)It is state mandatory on all systems Answer (All of the above) What is the piping between the backflow device and the zone valve called? Main line What is the piping between the zone valve and the sprinkler heads called? Lateral piping Which of the following is not acceptable? (B)Threading a metal into a plastic fitting In wiring, larger the number: (D)Smaller the wire size Watering early morning: (A)Allows for better pressure(B)Has less evaporation (C)Has less wind distortion(D)Encourages healthier plant material Answer is (All of above) What happens if two different types of metal pipes are connected together? Electrolysis

An engineer scale is: A measuring device that has measurements as a given number of feet per inch In calculating the available water capacity,pressure loss through the water meter should not exceed what percentage of the minimum static water pressure available? 10 The maximum water flow through the water meter should not exceed: 75% of the safe flow of the meter What is the maximum acceptable velocity of the water flow through the copper service line? 9 fps (feet per second) Water loss in plant material is a combination of: Evaporation and transpiration Evapotranspiration is a combination of: Evaporation and Transpiration What is capillary action? The main effect distributing water horizontally through the soil Which soil type has the slowest infiltration rate? Clay