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CWEA Grade I Laboratory Analyst questions and answers
Chloride - Major anion found in many natural waters - Can impart salty taste in H2O What increases concentration of chloride in wastewater Chlori... [Show More] de in human diet and softeners flushed into sanitary sewer system 2 most prevalent methods of measuring chloride argentometric and mercuric nitrate Argentometric Titration of sample with standard solution of silver nitrate (AgNO3) - Indicator: Chromate ions (CrO4) - End point: reddish silver chromate Mercuric Nitrate Titration with standard mercuric nitrate solution -pH must be adjusted between 2.3 and 2.8 - Indicator: Diphenyl carbazone - End point: Change from blue to purple in presence of mercury Interference of Mercuric Nitrate Method Sulfide, bromide, orthophosphate (over 30 ppm), and iodide Why does color change in water Presence of decaying vegetable matter, metal ions (ie. iron) or industrial and domestic pollution How is color measured Measured using visual comparison method Visual comparison method Sample compared to standards using matched nessler tubes - Standards prepared with solution containing cholorplatinate and cobaltous chloride Standard units for color One unit= color resulting from 1 mg of platinum/L 2 color reporting True and Apparent True color Color from dissolved substances, determine using sample treated to remove turbidity Apparent Color Includes dissolved and suspended solids Conductivity H2Os capability to pass electrical flow Conductivity of pure water 0 Units of conductivity micromhos/cm Temperature conductivity should be read at 25 degrees Celcius How is conductivity affected Mobility of ions, conductivity is dependent on viscosity Viscosity A liquids ability to resist flow, higher the viscosity the lower the flow Relationship of temperature and viscosity Inverse Acid A compound which liberates hydrogen ions and has a pH below 7. Alkalinity: The measurement of a sample's capacity to neutralize acid. Alkalinity measures The carbonate, bicarbonate, and hydroxide ion concentration found in water Primary reason for measuring alkalinity Used in control of many water and wastewater unit processes How is alkalinity measured Titration of a sample with a standard solution of either sulfuric acid or hydrochloric acid to predetermined pH endpoint The phenolphthalein alkalinity of a water sample is zero if: The pH is greater than 8.3 Atomic Weight: The sum of the number of protons and the number of neutrons in the nucleus of an atom. Atomic weights of elements are found on periodic tables. Base: A compound which liberates hydroxide ions and has a pH above 7. Biochemical Oxygen Demand (BOD): The quantity of oxygen utilized in the biochemical oxidation of organic matter under standard laboratory procedures for five days at 20° Centigrade, usually expressed as a concentration (e.g., mg/L). BOD measurements are used to indicate the organic "strength" of wastewater. Chain-of-Custody: A legal record (which may be a series of records) of each person who had possession of an environmental sample, from the person releasing the sample, to the person who collected the sample, to the person who analyzed the sample in the laboratory, to the person who witnessed the disposal of the sample. Chemical Oxygen Demand (COD): The amount of oxygen (expressed in mg/L) consumed from the oxidation of pollutants during a specific test. As such, COD is a measure of the oxygen-consuming capacity of the pollutants present in wastewater. The results of the COD test are not necessarily related to the BOD, because the chemical oxidant responsible for utilizing the oxygen may react with substances which bacteria do not stabilize. Composite Sample: A collection of individual samples obtained at regular intervals, based either on flow or time. The individual samples are combined proportionally. .If you have been given instructions you dont understand Ask the author Mercuric nitrate titration technique for measureing chloride is falling into disuse in the lab because Mercury creates a hazardous waste problem Standard phenylarsine oxide solution (PAO) Should be handled with caution because its is a severe poison Sampling protocol for chloride includes Glass or plastic container with no preservative Incubator temperature for BOD 20 +/- 1 degrees C Laboratory mistakes may be corrected by Lining out the mistake with pen and writing the correct answer to the side of the first, with analysts initials and date The sample receiving log must record time and date sampled Sample collector, nature of sample, analyses to be performed, preservatives, condition of sample and sample recipient Hood flow should be monitored and documented at 100 linear feet per minute Normality equation (N1)(V1)=(N2)(V2) Lauryl Sulfate Broth is sterilized before use for 15 minutes at 121 degrees C Agar medium is used for Heterotrophic plate count During acid base titration, titrant is added to the sample with Buret When preparing diluted calibration standards from a stock standard, use combination of the following to get the most precise standard Class A volumetric flask and class A volumetric pipet At a given temperature, the intensity of the acidic or basic character of a solution is indicated by pH or hydrogen ion activity pH measurement requires the following voltmeter, glass pH electrode, reference electrode, and a temperature compensating device Conductance measurements are temperature compensated to 25 degrees C Conductivity meter is calibrated with 0.0100 N potassium chloride standard Alkalinity is reported as Alkalinity mg CaCO3/L The hardness determination by EDTA titration measures Calcium and magnesium The indicator for the hardness determination is eriochrome Black T EPA acceptable primary standards for the turbidity determination include formazine only BOD determination is an empirical test in which standardized lab procedures are used to determine the relative oxygen requirements of wastewaters, effluents and polluted waters Sample pretreatment for BOD assuring that the samples are neutralized to pH range between 6.5 and 7.5 and any residual chlorine has been dechlorinated Disinfection Process designed to kill most microorganisms in wastewater, including all essentially pathogenic bacteria Fecal coliform bacteria Bacteria found in feces of warm blooded animals Total coliform group All of the aerobic and faculative anaerobic, gram negative, nonspore-forming, rod shaped bacteria that ferment lactose in 24-48 hours at 35 degrees C Lab test results for an individual environmental sample within an analytical batch may be rejected when A known error has occured Precision is measured by Analyzing replicate samples Accuracy The combination of bias and precision of an analytical procedure, which reflects the closeness of a measured value to a true value Bias Consistent deviation of measured values from the true value, caused by systematic errors in a procedure Precision Measures the degree of agreement among replicate analyses of a sample, usually expressed as the standard deviation Random Error Consistent deviation of measured values from the true value, caused by systematic errors in a procedure Total Solids Well mixed sample is evaporated in a weighed dish and dried to constant weight in an oven at 103-105 degrees C Preparing Total solids evaporating dish Ignite clean evaporating dish at 550 furnace for 1 hour and store and cool in desicator Analysis procedure of total solids 1. Choose sample volume that will yield residue between 2.5 and 200 mg 2. Dry evaporated sample for 1 hour in 103-105 degree C oven 3. Cool in desicator and weigh to constant weight Constant weight for total solids Weight change is less than 4% of previous weight or 0.5 mg Total Dissolved Solids A well mixed sample is filtered through standard glass fiber filter and filtrate is evaporated to dryness in weighed dish and dried to constant weight at 180 degrees C Preparing glass fiber filter disk Apply vacuum and wash disk with 3 successive 20 mL volumes of reagent grade water Preparing evaporating dish for TDS If volatile solids, Ignite cleaned evaporating dish at 550 for 1 hour in furnace If only TDS, heat cleaned dish to 180 for 1 hour Analysis procedure of total dissolved solids 1. Stir sample with magnetic stirrer and pipet measured volume onto glass fiber filter with applied vacuum 2. Wash with 3 successive 10 ml volumes of reagent grade water 3. Suction for 3 minutes after filtration is complete 4. Transfer total filtrate to weighed evaporating dish and evaporate to dryness 5. Dry evaporated sample for 1 hour in 180 +/- 2 degree C 6. Cool and weigh to constant weight Total Suspended Solids A well mixed sample filtered through weighed standard glass fiber filter and residue retained is dried to constant weight at 103-105 degrees C Analysis procedure of total suspended solids 1. Wet filter to seat it 2. Pipet measured volume to filter 3. Wash filter with 3 successive 10 mL wash of reagent grade water and continue suction for 3 minutes 4. Dry for 1 hour in 103-105 degree C oven 5. Cool in desicator and weigh until constant weight [Show Less]
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Cwea collections Grade 1 questions and answers| all verified
Sewer maintenance vehicles are difficult to maneuver At low concentrations, hydrogen sulfide smells like Rotten Eggs which safety hazard in... [Show More] a collection system operations can be detected by an insturment? Toxic Gases What must be checked first before entering a manhole? Proper barricades or warning devices around manhole. When should field crews use signs and cones? When over half the street is blocked. The different zones of traffic control include buffer Elements of defensive driving include having your vehicle under control The primary function of an entry supervisor is to maintain overall saftey of permited confied space operations What should be the alarm set point for oxygen in an atmospheric monitoring/testing device? 19.5% Warning,caution,danger,on a label means Hazardous MSDS means Material Data Safety Sheet What is the purpose of the OSHA Hazard Communication SHeet To make sure employees know about any hazardous chemicals they may contact How can traffic be warned of your presence in the street? Signs,Cones,Flagman What check should be preformed before driving a vehicle? Mechanical/Safety Where will collection system operators most likely find black windows Spiders and scorpions. Manholes Typical safety hazards in collections system operations include Oxygen defiency You have an air compressor and you have been instructed to compact the backfill in a trench. Which of the following is the best tool to use? Tamper Which type of shovel do collection system technologist use Grit Shovel What type of saw is used to cut asphalt? Diamond bladed or toothed power saw Googles, earplugs, and glove are needed when using a Power Grinder What type of equipment should be used to excavate a broken sewer pipe? Backhoe What is a mechanical means to dislodge material from a sewer? Scraping The formula for calculating the volume of a wet well is V=WLH Tasks preformed by a collection system operator includes: Maintaining collection system equipment One cubic food per second flow is equal to 26,928 Gallons To properly operate a power rodder Make sure all the torque is out of it before handling. The diameter of a wet well is 10 feet. If filled to a depth of 10 feet, it will contain approximately Show Work = 5,872 Gallons [Show Less]
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CWEA Collection Systems Maintenance questions and answers latest updated
Why are gasoline and volatile solvents objectionable when present in a sewer? They produce an explosion hazard You should never attempt to install,... [Show More] maintain, repair or replace electrical equipment panels, controls, wiring or circuits unless You know what you are doing, are qualified and are authorized What are the different areas of traffic zones? Advance Warning Area, Transition Area, Activity Area (buffer space and work space), Termination Area. Could be 4 or 5, justify your answer on the test! why should hydrogen sulfide be controlled? to protect from corrosion and odors Personnel entering a Permit Required Confined Space must have the following training entry and rescue To find protective gear before application of a product, you should: look at the MSDS The gas most commonly associated with septic wastewater is Hydrogen Sulfide The lack of an unpleasant odor in a manhole, lift station or other structures does not always mean that dangerous gases are not present because: some dangerous gasses are odorless (for example, carbon monoxide) What are the four conditions necessary to create an explosion? combustible gas, adequate oxygen, heat and proper mixing of gas and oxygen what does the "transition area" mean in traffic control? It moves traffic out of its normal path what elements should be considered to improve worker safety in High speed Temporary Traffic control Zones? Rerouting traffic around the work site, positioning of law enforcement officers in the temporary traffic control zone, and work zone training What key features would you need to address when developing an S.O.P. for a Lift Station failure? Traffic Control Plan, By-Pass connections, and Spill containment What tools are used with a power rodder? Spring Blades Tools used for sewer rodding include: porcupine, root saw, square bar cork screw What tool would you use to cut VCP pipe? Chain Pipe Cutter Which conditions should a gas detection device test for? Hydrogen sulfide, explosive/flammable gases, oxygen What does "LEL" mean on a gas detection meter? Lower Explosive Limit The oxygen level alarm normally goes off if oxygen levels are below: 19.5 percent When developing an S.O.P. for scheduled maintenance of electrical equipment, what program should be addressed as a primary safety guideline? The L.O.T.O Program What does L.O.T.O. Stand for? Lock out tag out What document would you require to be referenced when developing an S.O.p. for hazardous substace spill clean up? M.S.D.S. in developing an S.O.P. for air monitoring in a Permit Required Confined Space you would include what two factors? Placement of the blower and a weather forecast According to the State Water Resources Control Board Order No. 2006-003-DWQ, each enrollee must develop and implement a system-specific: SSMP (Sewer System Management Plan) How long do you have to report a category 1 SSO? 2 hours To report in the Statewide SSO Data-base California Integrated Water Quality System (CIWQS) regarding the location of a Category 2 SSO, how must you report the location? Using the GPS coordinates Biological activity in long, sluggish-flow, flat grade sewer lines will likely cause: odors Flatter sewer line grades may cause added sewer maintenance expense and odor nuisance. This is caused by what? A decrease in velocity which allows organic and inorganic solids to settle out. This, in turn, allows biological activity to happen which corrodes the pipe and releases hydrogen sulfide (H2S) which smells like rotten eggs Clear water in entering a collection system is called what? infiltration Infiltration can occur in a pipe when the pipe is: cracked, broken, fractures, has roots coming into it etc. The main reason we add sodium hypochlorite to sewers is to control: BOD Roots can enter collection systems through: cracked pipes, broken pipes, fractured pipes The lowest point on the inside of a pipe is called what? the invert The very top of the outside of a pipe is called what? The crown How often must an excavation site and adjacent areas be inspected for hazardous conditions? Daily protective shoring systems options include: proper shoring or benching of the sides of the excavation, supporting the sides of a tench with shoring using a shield in an excavation area. Proper operation and maintenance of wastewater collection is defined as: keeping wastewater flowing through pipes What is minimum design velocity for a sewer? a minimum of two feet per second Vitrified clay pipe is what type of pipe? Rigid What is another name for a manhole? Maintenance hole What are the four parts of a manhole? lid, cone, barrel and base What are some sewer testing methods? Air, water, mandrill, smoke, dye, lamping What are some hydraulic cleaning methods? Flushing, balling, kites, parachutes, poly pigs (pigging), high velocity cleaning, jetting, skids and tiger tails. what is the formula for the area of a square? Length x width The main advantage of using CCTV is what? You can see and record the length and severity of defective pipe A hazard that may damage a TV camera going through a sewer is: an offset joint What is the formula for the volume of a cube? Length x Width x Height What is the formula for the area of a circle? 0.785 x Diameter x Diameter What is the formula for the volume of a pipe? 0.785 x Diameter x Diameter x Length A flow of 650 pgm would be how many mgd? 0.936 How can the members of a balling crew communicate with each other? Hand Signals Why must you always know where a cleaning tool is in a sewer? so you know where obstructions or difficulties are encountered emergency stoppages in pipelines may be cleared safely by use of: high velocity cleaners rodents and insects can be controlled by spraying manholes with an approved pesticide Sources of excessive clear water in a collection system are usually caused by: infiltration from a high water table How many types of common shoring are there? 6 What is the "dirt" formula? distance = rate x time What is the total volume (in gallons) of 1,000 feet of 8-inch pipeline? 2,611 gallons What is the most critical task in operation and maintenance of wastewater collection? Keeping wastewater flowing through pipes Once enrolled in CIWQS, the "Collection System Questionnaire" must be updated at least every: 12 Months You arrive at an SSO and relieve the stoppage 27 minutes after a call was placed to report it. You find that the spill was running at 6 gallons per minute, how much sewage went uncaptured? 162 gallons What would cause a pump to deliver less than its expected rate of discharge? clogged impeller Why are wear rings installed in a pump? To concentrate wear on rings instead of volute and impeller What control devices are used to start and stop pumps? Floats What type of pump is used in lift station wet wells? Submersible Based on new Best Practices of the Common Ground Alliance for marking underground Utilities, the Inquiry Identification Number for an Underground Service Alert (USA) is viable for how many days? 28 days A person who completes a training program in accordance with the requirements of Title 8, Calif. Code of Regulations, Minimum Guidelines of the Common Ground Alliance is considered a ______________ person Qualified Person You receive a dispatch at 4:30 pm informing you that raw sewage spewing out of a manhole onto the ground and into an adjacent small stream. The caller said the sewer has been overflowing since 2pm. You arrive at 5:15 and find that the spill is overflowing at 166 gallons per minute. You clear the problem after 22 minutes, how many reportable unrecoverable gallons of raw sewage had reached the creek? 36,022 gallons (don't be intimidated by how long these word problems are! Just find the important information and take it one step at a time.) "High priority subsurface installations ae high pressure natural gas pipelines with normal operating pressures greater than 415 kPa gauge, petroleum pipelines, conductors or cables that are potentially hazardous to employees, or the public, if damaged." This paragraph indicates that before the start date of an excavation, what should occur? An agreed upon site visit Temporary traffic control lanes created as part of a Temporary Traffic control Zone setup on a street with a 35 MPH maximum speed limit shall be a minimum width of ______ 10 ft For a nighttime Short Term Stationary Traffic Control Zone setup on low speed/ low volume street, the minimum height of the traffic cones used shall be ________ 28 inches After completing a Temporary Traffic Control setup for your work zone it is a good practice to: Observe how effective your TTC setup is working to control traffic and make the necessary changes When a citizen wants information regarding a maintenance operation you should: Give them as much factual information as you can and offer to help them further Before starting a maintenance operation in a basement located in the backyard of a residence you should: contact the resident and politely ask permission to enter their backyard Maintenance programs are based on: Preventative and corrective maintenance principles The goal of preventative maintenance is to? Avoid breakdowns, severe damage, or harmful depreciation What is the definition of a sanitary sewer system? Any system of pipes, pump stations, sewer lines, or other conveyances, upstream of a wastewater treatment plant head work comprised of more than one mile of pipes and sewer lines, used to collect and convey wastewater to a publicly owned treatment facility What is the definition of "hydraulic capacity"? The maximum flow a pipe is expected to function at without creating a back up or discharge What is the minimum velocity in a gravity sewer pipe? 2 ft/s. This speed prevents the settling of solids, which in turn prevents corrosion and odor build-up What are the access points of a gravity sewer system? Manholes, Lift stations, Building connections, junction chambers, terminal cleanouts What is an Easement? The legal right that allows placement of sewer in privately owned property What is the springline? The theoretical center of the pipe What is the top of the pipe called? The crown What is the lowest point inside of a pipe called? The invert What are some examples of rigid pipe? Vitrified clay pipe (VCP), Concrete pipe, other rigid pipe, cast iron. They can support loads without as much back fill/ side support, but cannot distort without cracking or breaking What are some examples of flexible pipe? Ductile-iron pipe, steel pipe, thermoplastic pipe (PVC, HDPE, ABS), Orangeburg What is the name of the testing that confirms your pipe was not bent under pressure from being buried? Mandrel Inspection, also know as "pigging" What is an Operating Range? It is the range in which the pump in a pump station is on What are some examples of level control devices (devices that turn a pump at a pump station on and off)? Bubbler Level Gauge, Mercury/Mechanical Float Switches, Ultra Sonic Sensor What are some common types of valves? Plug, Gate, Butterfly, Ball, Check What is infiltration? water ENTERING a sewer through pipe joints, cracks or voids what is ex-filtration? leakage OUT of pipes through joints, cracks or voids [Show Less]
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CWEA Collections System Maintenance Grade 3 questions and answers
A Flagger should Stand? A. On the shoulder adjacent to traffic being controlled B. In the closed lane before stopping vehicle traffic C. In the traffic ... [Show More] lane. D. As stated in "A" or "B" above. D. As stated in "A" or "B" above. Legally responsible officials are required to report category 1 sanitary sewer overflows? A. Within 30 days B. Before end of the day C. As soon as possible D. Within 2 hours D. Within 2 hours When working in confined spaces or sewers, what form of lighting would you use? A. Mirrors to direct the sunlight or explosion proof lighting. B. Ordinary electric lights C. Propane, Gas, or kerosene lanterns D. Special matches A. Mirrors to direct the sunlight or explosion proof lighting. What can happen if water-based substances are used to extinguish electrical fires? a. Nothing but extinguish the fire b. The fumes are not harmful c. Receive an electrical shock d. They will corrode the electrical contacts c. Receive an electrical shock When testing a manhole for explosive gases when should the first tests be made? a. After removing the manhole cover b. Before removing the manhole cover c. At any time d. After ventilation b. Before removing the manhole cover Atmospheric hazards encountered in manholes can include: a. non-explosive atmospheres. b. non-toxic atmosphere. c. lack of oxygen. d. non-flammable atmospheres. c. lack of oxygen. When setting up to ventilate a manhole, the air inlet should be how many feet above street level? a. 4.0 b. 3.0 c. 2.0 d. 1.0 c. 2.0 Which chemical may be used for odor control in a sewer system? a. Calcium chloride b. Hydrogen peroxide c. Oxidized aluminum d. Sodium chloride b. Hydrogen peroxide What information must be on a warning tag attached to a switch that has been locked out? a. Directions for removing tag. b. Name of nearest physician to call in case of emergency. c. Signature of person who locked out switch and who is the only person authorized to remove tag. d. Time to unlock switch. c. Signature of person who locked out switch and who is the only person authorized to remove tag. Under what conditions must each member of the rescue service practice permit space rescues? a. At least once a year in a simulated situation or by the satisfactory performance of an actual rescue. b. At least twice a year in simulated situations. c. At least once a year in simulated situation using non-representative space conditions d. At least four times a year. a. At least once a year in a simulated situation or by the satisfactory performance of an actual rescue. How is a permit-required space described? a. Has or may contain atmospheric, engulfment, design, or other serious health/safety hazard. b. Is large enough to enter and work in and is meant for continuous occupancy. c. Is large enough to enter and work in and has an unrestricted entry/exit. d. Never contains an atmospheric or engulfment hazard. a. Has or may contain atmospheric, engulfment, design, or other serious health/safety hazard. What are the three duties of personnel in a Confined Space entry? a. Authorized entrants, parking attendants, entry supervisors. b. Unauthorized entrants, attendants, entry supervisors. c. Authorized entrants, attendants, entry supervisors. d. Authorized entrants, attendants, evening supervisors c. Authorized entrants, attendants, entry supervisors. What is an important element of hydrogen sulfide production? a. Flow velocity. b. Pipe materials. c. Amount of odor present. d. Amount of inorganic materials. a. Flow velocity. Which of the following is the most common factor leading to the generation of hydrogen sulfide in sewers? a. Anaerobic conditions. b. Constantly high velocity of flow in sewers. c. Low concentrations of ferrous sulfide. d. Presence of highly soluble fats and oils. a. Anaerobic conditions. A category 2 SSO is: a. any SSO which does not reach surface waters. b. not reportable. c. preventable. d. any SSO which is not category 1. d. any SSO which is not category 1. Which tool would you use for cleaning under a pipe, or hard dirt near a pipe? a. Miner's pick. b. Wrench. c. Drill. d. Hammer. a. Miner's pick. A torque wrench is used to tighten which device? a. Pipe clamp. b. Drill chuck. c. Light bulb. d. Sheet metal screw a. Pipe clamp. Which unit uses high water pressure and a vacuum to clean sewer lines? a. Jetter b. Mechanical rodder c. Combination unit d. Bucket machine c. Combination unit In sewer maintenance, what is a pig? a. A ball forced through a sewer line. b. A power rod. c. Any foul smelling equipment. d. The hydraulic rodding truck. a. A ball forced through a sewer line. When pouring a concrete slab, which of the following tools is used to finish the concrete? a. Grasshopper. b. Tamper. c. Trowel. d. Vibrator. c. Trowel. What tool is used to snare a broken section of sewer rod? a. Square stock corkscrew. b. Auger. c. Pickup tool. d. Pull out tool. c. Pickup tool. Why is the replacement of wastewater collection systems in some downtown streets difficult? a. Crowding of other underground utilities. b. Records have not been maintained properly and the collection system is lost. c. Some people have landscaped their backyards over the collection system and do not want their yards dug up. d. The streets will have to be paved again a. Crowding of other underground utilities. How can the velocity of water flowing in a sewer be estimated? a. Driving between manholes and reading the speedometer. b. Measuring the Manning's roughness coefficient for the sewer. c. Measuring the time it takes for the dye to be carried by the wastewater between the two manholes. d. Measuring the time it takes to run between the two manholes. c. Measuring the time it takes for the dye to be carried by the wastewater between the two manholes. Drawings which are considered "As Built" would be? a. Construction drawings issued to the contractor. b. Corrected construction drawings showing changes made in the field installation. c. Detailed drawings of proposed construction. d. Sectional maps on file. b. Corrected construction drawings showing changes made in the field installation. In lieu of a shorting system, the sides or the walls of an excavation, or trench, may be: a. sloped 3:1. b. sloped 1:3. c. sloped 2:1. d. sloped 1:1. a. sloped 3:1. When a water main must be laid under a sewer main, the sewer pipe must be: a. lined with epoxy. b. cleaned carefully. c. replaced with water type pipe with pressure tight joints. d. taken out while the water main is being installed. c. replaced with water type pipe with pressure tight joints. Hydrogen peroxide controls odors in sewers by: a. decreasing the dissolved oxygen. b. neutralizing the PH. c. oxidizing sulfide compounds. d. providing a source of hydrogen ions. c. oxidizing sulfide compounds. Construction of a wastewater pipeline under a highway or railway without disrupting the traffic is done by? a. Drag lining. b. Dredging. c. Embankment excavation. d. Boring and jacking. d. Boring and jacking. When a grade conflict exists between a water main and a sewer main, which of the following is the best solution? a. Build a manhole around the sewer main and continue the water main through the manhole. b. Drop the sewer service under the water main and let it work like a siphon. c. Have the water main adjusted and hold the grade on the sewer main. d. Raise the sewer over the water main and install a sewer pump station. c. Have the water main adjusted and hold the grade on the sewer main. The reason newly constructed collection system sewers should be inspected is to: a. determine if the contractor has complied with plans and specifications. b. determine if smoke tests will be successful. c. determine if dye tests will be successful. d. determine if the streets are paved. a. determine if the contractor has complied with plans and specifications. A source of infiltration in a collection system is: a. new pipes. b. proper joint pipes. c. pipe liners d. broken pipe joints d. broken pipe joints What are the advantages of a video tape recording system? a. Cheaper than a Polaroid camera. b. Record and play private video tapes. c. The ability to see what's happening when the camera is underwater. d. The length and severity of defective areas that can be recorded for later study. d. The length and severity of defective areas that can be recorded for later study. Before conducting smoke testing you should: a. warn the public after smoke testing is completed. b. notify local police and fire departments only if a fire is started. c. notify local animal control departments in advance of testing. d. notify public, local police, and fire departments in advance of testing. d. notify public, local police, and fire departments in advance of testing. Manholes are installed in sewer lines for the access of: a. backflow devices. b. personnel and materials c. traffic control devices. d. survey equipment. b. personnel and materials Anaerobic wastewater is frequently corrosive to materials it contacts, especially: a. coal tar enamel. b. concrete. c. stainless Steel. d. plastic. b. concrete. [Show Less]
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CWEA E/I Level 3, questions and answers with rated solutions | graded A+
If the potential difference across the coil is low, the coil will: A-draw too much current B-become too hot C-Produce too much magnetic force D-not hea... [Show More] t up D-not heat up The NEC identifies environments that contain flammable vapors and gases as which class of hazardous location? A-Class I B-Class II C-Class III D-Class IV A-Class I Which of the following reduces high voltages and currents to save values for measurements? A-auto transformer B-megohmmeter C-instrument transformer D-variable transformer C-instrument transformer In a three wire control circuit, when a power failure occurs: A-The interlock contact will close the circuit B-The operator can restart the meter automatically C-The motor can restart unexpectedly D-The operator must restart the meter manually D-The operator must restart the meter manually Push buttons are classified as standard duty or heavy duty according to the: A-Kind of enclosure B-Service conditions C-frequency operation D-Current carrying ability D-Current carrying ability He push to test pilot light is used in applications where the pilot light is: A-rarely needed B-A neon bulb C-used in DC applications D-in constant use A-rarely needed The advantage of LCDs over LEDs is: A-accuracy B-better visibility C-lower power consumption D-sensitivity C-lower power consumption Shielding protects an analog meter from: a. damage due to careless handling. b. harmful UV rays. c. over-current and surges. d. stray magnetic fields. d. stray magnetic fields. An ammeter should be connected: a. across the line. b. around an inductor. c. in parallel with the load. d. in series with the load. d. in series with the load. Bar graphs and wave forms can be displayed on a LCD screen when the multimeter has: a. analog/digital circuits. b. microprocessor circuitry. c. opposing coils and a commutator. d. parallel ports. b. microprocessor circuitry. The difference between the squirrel-cage rotor and the wound rotor is in: a. their pole-phase groups. b. how the conductors are connected. c. how the current is induced in the conductors. d. all of the above. b. how the conductors are connected. The frame, the core, the winding, and the end plates are all parts of the: a. rotor. b. stator. c. alternator. d. induction motor b. stator. Which of the following is a sign of overheating rotor bars? a. Reduced starting torque. b. Noise. c. Discoloration. d. All of the above. c. Discoloration. Two sources of power, one AC and one DC, are required for running a(n): a. induction motor. b. squirrel-cage motor. c. synchronous motor. d. wound-rotor motor. c. synchronous motor. Modern synchronous motors have: a. both brushes and slip rings. b. brushes, but no slip rings. c. slip rings, but no brushes. d. neither brushes nor slip rings. d. neither brushes nor slip rings. All the following are true of 240-volt systems compared to 480-volt systems, except: a. they cost more to operate. b. they require more current per unit of power. c. they require smaller circuit breakers. d. they are safer. c. they require smaller circuit breakers. If a charged capacitor is removed from a circuit, the capacitor: a. retains its charge. b. loses some of its charge. c. loses most of its charge. d. loses all of its charge. a. retains its charge. Control systems are usually designed so that each individual circuit controls: a. all functions of the machine. b. at least two functions. c. only one function. d. only one device. c. only one function. A 115-volt, 2-KVA, single-phase generator operating at full load will deliver how many amperes? a. 0.23 b. 17.4 c. 57.5 d. 230 b. 17.4 What is the current when a circuit has a 1,500- watt load and a power factor of 86%, and operates from a three-phase 230-volt source? a. 9.7 amps b. 6.5 amps c. 4.4 amps d. 3.8 amps c. 4.4 amps What is the amp-load of a three-phase, 0.5-hp, 230-volt motor with an efficiency rating of 92% and a power factor of 80%? a. 1.27 amps b. 1.19 amps c. 2.55 amps c. 4.41 amps a. 1.27 amps A three-phase, 460-volt motor draws a current of 52 amperes. The motor has an efficiency rating of 94% and a power factor of 80%. What is the horsepower? a. 24.1 hp b. 41.7 hp c. 50.0 hp d. 73.8 hp b. 41.7 hp A 120-volt AC circuit draws a current of 5 amperes. Determine the power consumption. a. 60 watts b. 120 watts c. 4.8 watts d. 600 watts d. 600 watts In a simple ratio system, the independent variable is: a. both measured and controlled. b. controlled but not measured. c. measured but not controlled. d. neither measured nor controlled. c. measured but not controlled. The root-mean-square method is used to calculate: a. integral and derivative action. b. proportional band or gain. c. system accuracy. d. transducer bias c. system accuracy. To simulate an RTD input, you use a: a. digital VOM. b. potentiometer. c. resistance decade box. d. wally box. c. resistance decade box. SCADA systems typically span: a. an entire plant. b. many miles. c. part of the plant. d. up to 5,000 feet. b. many miles. In the ISA tag PIC-21, the P stands for: a. Positive. b. Pressure. c. Process. d. Proportional. b. Pressure. The outputs of a digital transducer are in the form of: a. 1 to 5 mv. b. 4 to 20 ma. c. digital computer words. d. on or off signals. c. digital computer words. A shield around the signal lead is the most effective protection against: a. impedance. b. unwanted conductance. c. noise. d. inverted sources. c. noise. The most important consideration in loop control is: a. accessibility. b. accuracy. c. cost. d. response. d. response. Which element makes a programmable logic controller system flexible? a. Memory. b. I/O. c. Program. d. Power supply. c. Program. Local I/O expansion involves the addition of: a. a second processor. b. a shift register. c. data-handling capabilities. d. I/O points within the rack. d. I/O points within the rack. A major cause of problems in multi-layer printed circuit boards is: a. age. b. corrosion. c. interlayer separation. d. overheating. c. interlayer separation. A software problem that causes incorrect results is called a: a. bug. b. crash. c. glitch. d. spike a. bug. The CPU of a microcomputer is a(n): a. ALU. b. microcontroller. c. microprocessor. d. printed circuit assembly. c. microprocessor. Where is a computer's start-up program usually stored? a. In RAM b. In ROM c. On disk d. On magnetic tape b. In ROM How many signal conditions can digital I/O devices have? a. One b. Two c. Eight d. An infinite number b. Two A CDU (Command and Display Unit) computer screen that senses finger pressure is: a. a digitizer. b. an intelligent terminal. c. a scanner. d. a touch screen. d. a touch screen. [Show Less]
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CWEA E1 Study Set questions and answers latest updated
Confined Space A space that: -is large enough to enter and work. -has limited or restricted means for entry. -is not designed for continuous occupancy.... [Show More] Hot Work Permit An employer's written authorization to perform work capable of providing a source of ignition. Inerting A form of purging or ventilating a confined space where an inert gas (such as nitrogen, carbon dioxide or argon) is used to displace the atmosphere in a confined space to remove fire or explosion hazards. Causes oxygen levels to become unstable for re-entry. Oxygen Safe Zone 19.5% to 23.5% Below 19.5=unsafe for breathing Above 23.5=explosive Leader Line The part or area of a drawing to which a number, note or other reference applies. They are solid lines and usually terminate in a single arrowhead. Hydraulic Term: "Resistance" A construction in the bore of the pipe which requires more pressure to pass the same amount of water. Hydraulic Term: "Voltage" (Assume water is flowing horizontally so gravity isn't a factor) Electric potential is equivalent to pressure and the voltage (or voltage drop/potential difference) is the difference in pressure between two points. Hydraulic Term: "Current" Equivalent to a hydraulic volume flow rate; that is the volumetric quantity of flowing water over time. Ohm's Law Current through a conductor between two points is directly proportional to the voltage across the two points. S.O.P. Standard operating procedure. N.E.C. National Electrical Code. N.F.P.A. National Fire Protection Association NPT National pipe thread. Tapered pipe. Compound Gauge Displays negative AND positive pressure measurements Cat1 Meter Measures electronics Cat2 Meter Measures single-phase receptacles. Cat3 Meter Measures 3 phase distribution and single phase lighting equipment. Cat4 Meter Measures 3 phase at utility connection and any outdoor connections. L.O.T.O. Lock out tag out is an osha regulation. 3 elements needed to start a fire. Heat, oxygen and fuel. Class C fire. Electrical fire What is Rust Combination of water, oxygen and iron. Micrometer Torque Wrench does what when setting is reached? Clicks. V.F.D. Variable frequency drive used for AC motor speed in hertz. Bourdon Tube Gauge shape C shaped. 1 PSI = ? feet of water. 2.31 Partial Flume A device used to measure the flow in an open channel. The flume narrows to a throat of fixed dimensions and then expands again. The rate of flow can be calculated by measuring the difference in head (pressure) before and at the throat of the flume. Measuring at sea level and 8000' does an O2 sensor need recalibration. Yes, because of pressure difference. Hysteresis Input ascending and descending Turbine Flow Meters provide what kind of signal? Provide a frequency or pulse output signal What happens to wire resistance when temperature rises 10 degrees Celsius? It decreases 10%. Inductor Coil of wire that opposes any change in current. Magnetic Flow Meters show what when the water is low in conductivity? 0 reading if the fluid is low in conductivity. "Empty Meter" Purple U.S.A. marking. Reclaimed water. Orange U.S.A. marking. Telecommunication, alarm or signal lines conduit. Red U.S.A. marking. Electric power lines, cables or conduit. What happens when a motor loses one phase out of 3? Single phasing will cause the motor to trip the overload heaters. What does a Pitot tube do? Measures velocity of low to medium gas flow applications. PH range? 0-14 7 is neutral. Less than 7 is acidic. More than 7 is base (alkaline) How long is a confined space permit valid for according to OSHA? No longer than it takes to get the work done. Entry permits are valid for more than one shift if permit info contains provisions covering shifts. The voltage from phase to ground in a 480v transformer is? 277 volts. Signal range for pneumatics? 3-15psi. 3-6-9-12-15 Intrinsic safety is? Barrier preventing excess voltage or current from reaching in hazardous area. How do you add capacitors in series? Same as resistors. [Show Less]
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Grade 1 Mechanical Technologist Study Guide questions and answers 2023
Which welding process is most commonly used for small pipe maintenance welding? Oxyacetylene gas welding What is the proper definition of an engine... [Show More] ? It is a machine designed to convert energy into useful mechanical motion What is wet stacking and how can it be prevented? It is unburned fuel collecting in the exhaust due to light or no load conditions. To check flywheel face runout, where should the dial indicator be positioned? The base on the bell housing and pointer on the flywheel face. If a 38-tooth gear running at 360 rpm is driving another gear at 144 rpm, what is the number of teeth on the driven gear? Solution: driver Gear x Driver RPM=Driven Gear x Driven RPM 38 x 360 = N x 144 13,680 = 144N 13,680 / 144 = 144N / 144 95 = N (95 Tooth Gear Which of the following is required for a sealed ball bearing? It does not need to be lubricated under normal use. A DAFT is an acronym meaning: Dissolved Air Flotation Thickener. What is the governing agency that permits odor control systems? AQMD: Air Quality Management District At what pressure rating would you use a blower instead of a fan? 7 PSI Which of the following valves is unsuitable for high-pressure flow? A needle valve A sodium hypochlorite tank's full working capacity is 23,000 gallons. Its current level is at 1,200 gallons. How many gallons does the delivery driver need to add to bring it to 70% capacity? Solution: 23,000 gallons max capacity x 70% desired capacity = 16,100 gallons desired. 16,100 gallons desired - 1,200 gallons current level 14,900 gallons needed to add What is the result if 6/8 " is converted to decimal form? 6 / 8 = 0.75 or .75 What is the conversion of 212 degrees Fahrenheit into Celsius? What is the conversion of 100 degrees Celsius into Fahrenheit? C° = (F° - 32)/9 x 5 •Begin by subtracting 32 from the Fahrenheit number. •Divide the answer by 9. •Then multiply that answer by 5. To convert from Celsius to Fahrenheit: F° = (C° x 9/5) +32•Begin by multiplying the Celsius temperature by 9. •Divide the answer by 5. •Now add 32. =212 degrees F [Show Less]
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CWEA E/I 2 Study Guide Quest 100% accurate answers
Receiving job instruction and planning equipment use are part of: a. craft data. b. job preparation. c. work factors. d. leveled time. b. job prepara... [Show More] tion Anticipating other tasks or problems: a. usually creates additional problems. b. wastes time. c. sharply reduces the number of emergencies. d. often is not worth the effort. c sharply reduces the number of emergencies Making job planning a group effort: a. wastes time. b. improves productivity. c. causes confusion. d. All the above b improves productivity Rubber safety gloves should be tested how often? a Every 12 months b. Every 9 months c. Every 6 months d. Every 4 months a Every 12 months Rubber safety blankets should be tested how often? a. Every 6 months b. Every 9 months c. Every 12 months d. Every 18 months b Every 9 months What is the interrupting current of a GFIC receptacle? a. 20 VAL b. 5 MA c. 10 UDL d. 20 MA b 5 MA What type of stepladder is forbidden while working on electrical equipment? a. Wood b. Fiberglass c. Aluminum d. Ceramic c Aluminum What is the killer of electrical shock? a. Voltage b. Current c. Resistance d. Ohms b Current The relationship between an electric current and a magnetic field is called: a. matter. b. atoms. c. electromagnetism. d. element c electromagnetism Electrons flowing from one place to another make a: a. current. b. track. c. circuit. d. channel a current Between two objects, the development of static charges creates a: a. potential difference. b. battery. c. thermocouple. d. resistance a potential difference A coil of wire that carries an electric current is called a: a. conductor. b. thermocouple. c. electrocurrent. d. electromagnet d electromagnet Metals are good conductors because they have many: a. insulators. b. free electrons. c. resistors. d. inductors. b free electrons The amount of potential difference a layer of insulation can withstand without breaking down is: a. resistance. b. voltage drop. c. dielectric strength. d. ampacity c dielectric strength What is the property of a coil of wire that opposes any change in the current in the coil? a. Inductance b. Resistance c. Impedance d. Watts a Inductance What is the correct name for "voltage" or electromotive force? a. Element b. Electron c. Circuit d. Potential difference d Potential difference A rate of flow of one coulomb per second is called one: a. ampere. b. joule. c. volt. d. olhum. a ampere What is the name for the proportional relationship between potential difference and current? a. Voltage drop b. Voltmeter c. Ampmeter d. Watt meter b Voltmeter What is the unit of measurement for capacitive reactance? a. Volts b. Ohms c. Amps d. Power factor b Ohms Power companies use AC generators because AC can be sent over long distances: a. at high cost. b. at low cost. c. slower. d. faster. b at low cost What device changes alternating current to a different combination of voltage and current? a. Generator b. Capacitor c. Alternator d. Transformer d Transformer How does the power going into a transformer compare to the power coming out? a. Lower b. Equal c. Double d. Higher b Equal What changes continuously around the conductor when current changes continuousl in AC circuits? a. Voltage b. Current c. Magnetic field d. Amps c Magnetic field Wires and cables can be classified according to their: a. color. b. size. c. covering. d. shape. c covering. What kind of starter provides full-voltage starting? a. Across-the-line b. Synchronous start c. Reactor starter d. Reduced-voltage start a Across-the-line The choice between across-the-line starting and reduced-voltage starting depends in part on the size of the: a. starter. b. wire size. c. motor. d. breaker. c motor. The most important requirement for good maintenance of motor starters is: a. good record keeping. b. safety of personnel. c. proper lubrication. d. clean, dry insulation c proper lubrication A reversing starter reverses a three-phase motor by interchanging: a. main contacts. b. two of the line leads. c. all of the line leads. d. control voltage. b two of the line leads What kind of protection is provided in a manual across-the-line three-phase motor control? a. Overload protection only b. Ground-fault protection only c. Short-circuit protection only d. All of the above a Overload protection only Commonly used instead of fuses in industrial power distribution systems are: a. disconnects. b. motor starters. c. overcurrent relays. d. circuit breakers. d circuit breakers. Distribution protection usually consists of two elements, protection of both: a. equipment and circuit. b. personnel and equipment. c. wire and control relay. d. ground fault and current. a equipment and circuit What is the current in amperes of a 120-volt circuit with a resistance of 60 ohms, using Ohm's Law? a. 0.5 amperes b. 2.0 amperes c. 30 amperes d. 10 amperes b 2.0 amperes Solving for I: I = ER Substituting values into the equation: I = 120 volts/60 Ohms = 2 amperes What is the current for a 120-volt circuit with a 1440-watt load? a. 0.083 amperes b. 10 amperes c. 12 amperes d. 15 amperes c 12 amperes Since P = EI, current can be determined as I = P/E Substituting values into the equation: I = 1440 watts /120 volts = 12 amperes What is the current of a circuit that consumes 625 watts through a 12.75-ohm resistor? a. 3.8 amperes b. 7 amperes c. 49 amperes d. 175 amperes b 7 amperes E = IR and P = EI Substituting the first equation into the second: P = (IR)I P = I Squared x R Solving for I: I Squared = P / R I = SqRt P/R I = SqRt 625/12.75 I = SqRt 49 I = 7 amps What is the ampere load of a single-phase 1/2 horsepower 115-volt motor, if the motor has an efficiency rating 92% and power factor of 80%? a. 9.5 amperes b. 2.4 amperes c. 4.4 amperes d. 78.1 amperes c 4.4 amperes Use the formula I = 746 x horsepower / voltage x efficiency x power factor, where I is the current. I = 746 x 0.5 / 115 x 0.92 x 0.80 = 4.4 amperes A 230-volt single-phase circuit has a 12-kilowatt power load and operates at 84% power factor. What is the current? a. 43 amperes b. 52 amperes c. 62 amperes d. 70 amperes c 62 amperes the formula I = kilowatts x 1.000 / voltage x power factor where I is the current. I = 12 x 1.000 / 230 x 0.84 = 62 amperes The difference between the measurement signal and the set point is called the: a. gap. b. error. c. feedback. d. span. b error The signal pressure is usually directly proportional to the process: a. span. b. level. c. variable. d. loop. c variable Offset is the difference between the actual maintained value of the measured variable and: a. the set-point. b. the span. c. zero. d. the level. a the set-point Another name for built-in error that usually occurs in a proportional control system is: a. deadband. b. offset. c. set point. d. span. b offset An automatic controller always compares a measured variable to: a. zero. b. span. c. reset. d. set point. d set point. The specific value at which an automatic control holds a process variable is called the: a. span. b. variable. c. control point. d. set point. c control point The drawing that provides a view of the entire system in process control is the: a. P&ID drawing. b. I/P drawing. c. element drawing. d. primary drawing. a P&ID drawing A tag number with a code reading FRC identifies a. field recording controller. b. flow recorder controller. c. temperature controller. d. pressure recorder. b flow recorder controller The most commonly used type of diagram in process control is: a. a loop diagram. b. an installation drawing. c. a piping and instrument drawing. d. a location drawing. c a piping and instrument drawing A signal from a measuring device to the controller is called: a. zero. b. correcting. c. span. d. feedback. d feedback. In a closed loop control system, the control process of measuring, comparing, computing and connecting goes on: a. continually. b. intermittently. c. never. d. whenever the operator takes some action. a continually A control system in which the output is regulated only by changes from outside the process is called: a. open loop. b. closed loop. c. set point. d. measuring. a open loop. A common converter used in process control is the I/P converter, which converts ________ signals to ________ signals. a. zero, span b. analog, digital c. current, pneumatic d. linear, nonlinear c current, pneumatic [Show Less]
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