Basic Water Works Operations Exam Quuestions and Complete Solutions

Basic Water Works Operations Exam Quuestions and Complete Solutions Water covers what percent of the Earth's surface? - Answer: 75% Excluding outside water use, the average household uses about _______ gallons of water per month for inside use - Answer: 2000 only about ______gallon of tap water per person per day is used for drinking and cooking - Answer: 1 monitoring what enables us to plan ahead for growth? - Answer: average and maximum daily water demand The Texas State board of Fire Insurance requires utilities that provide fire protection to have a minimum amount of water available based on _____ gals per person per day - Answer: 130 In Texas, about _____% of all water used is for commercial, industrial, or agricultural purposes - Answer: 75 Only about ___% of all fresh water on earth can be easily accessed for use - Answer: 1 The most common types of desalination/demineralization treatment technologies include: - Answer: RO (reverse osmosis) and EDR (electrodialysis reversal) The city of El Paso is treating about ____ MGD of raw sewage to drinking water quality - Answer: 70 True or false: PWS officials should be pro-active in their approach to terrorism - Answer: true Nature's way of recycling out water is a process called the ___________cycle - Answer: hydrologic Precipitation that trickles into the ground recharging aquifers is called _______________ - Answer: percolation Water is called the ____________________and is not found pure in nature - Answer: universal solvent examples of organic matter found in water include: - Answer: bacteria, viruses, and protozoa Examples of inorganic matter found in water include: - Answer: rock, sand, metals, and minerals The physical characteristics of water are: - Answer: color, taste, odor, temperature, and turbidity ___________________ color is dissolved in water and cannot be removed by filtration - Answer: true true or false: the red color caused by iron is an example of suspended or apparent color and it can be removed by filtration - Answer: true the state recommends ____________ color units or less for a quality water - Answer: 15 (good tasting) - Answer: palatable taste and odor can come from organisms such as: - Answer: vegetation, bacteria, and algae, and from certain chemicals and metals Threshold odor number (TON) - Answer: Relates to the number of dilutions needed for the water to be odorless The state recommends a TON of ____ or less - Answer: 3 the deeper the well, the ____________the water - Answer: warmer the amount of suspended matter in water and causes the water to be cloudy - Answer: turbidity The state requires filtered water to be equal to or less than ___turbidity units in at least ____% of the monthly samples - Answer: 0.3 / 95% why must turbidity be limited? - Answer: it shelters and nourishes bacteria and interferes with disinfection chemical characteristics of water include: - Answer: solids, water hardness, Ph, and gasses mg/L is interchangeable with what term? - Answer: ppm one ppm or 1 mg/L means that for every ____pounds of water there is one pound of material in it - Answer: 1,000,000 Dissolved solids are _______ and cannot be filtered out - Answer: in solution The state recommends a maximum total dissolved solids content of ________mg/L - Answer: 1000 what are the primary causes of hardness in water? - Answer: excessive calcium and magnesium An alkaline or basic solution has a pH greater than - Answer: 7 the State recommends a water pH or greater than ______ be maintained at all times - Answer: 7 what are 3 common gasses found in water? - Answer: methane, carbon dioxide, and hydrogen sulfide potable water means it is safe to drink and has a measurable _____________ - Answer: chlorine residual true or false: The state must be notified after an existing facility is changed or after construction of a new facility - Answer: true the plant operator is responsible for a sufficient supply of safe, __________ drinking water - Answer: palatable a distribution operator may: - Answer: repair leaks, make taps, flush mains, and take bacteriological samples meter readers bring in operating revenue and profoundly impact ___________Relations - Answer: public a class D license is valid for ____years at ground and purchase water systems with ___ connections or less - Answer: 3/250 The federal regulator of drinking water is the - Answer: EPA sets standards for drinking water including physical, chemical, bacteriological, and radiological characteristics - Answer: Safe Drinking Water Act the primary state regulator of water utilities - Answer: TCEQ Sets standards, reviews construction plans, administers licensing, conducts sanitary surveys, and enforces the Safe Drinking Water Act - Answer: the TCEQ To be classified as a public water system, the system must have at least ___ service connections or serve at least _____individuals at least _____days out of the year - Answer: 15/25/60 TCEQ requires chemical analyses and sanitary survey reports to be kept at least ___yrs - Answer: 10 examples of transient, non-community PWS - Answer: highway rest stops, campgrounds, RV parks, motels, churches, and restaurants examples of nontransient-noncommunity PWS - Answer: Factories, industries, office buildings, daycare centers, and rural schools pathogens - Answer: Disease causing microorganisms pathogens and diseases found in water are called - Answer: waterborne true or false: if fecal waste from an infected person gets into a water supply, the illness cannot be transmitted to a healthy person - Answer: false a waterborne disease that threatens humans is - Answer: typhoid A certain group of bacteria is used to indicate the possible presence of a pathogen --the _________group - Answer: total coliform true or false: the presence of fecal coliform in a water sample indicates fecal contamination from a human or warm-blooded animal - Answer: true true or false: the term "total coliform" means fecal and non-fecal coliform - Answer: true samples must be taken in sterile containers containing __________ which neutralizes chlorine - Answer: sodium thiosulfate purpose of the sample site plan - Answer: to assure bacteriological samples are collected from active service connections which are representative of the distribution system when selecting a sample site, choose a non-leaking faucet at least ____inches above the ground and made of material that can be heated or can withstand a chlorine solution or alcohol - Answer: 18 if there is no __________at a faucet, do not sample, flush longer - Answer: chlorine residual bleach or alcohol require ________contact time than flaming to disinfect a faucet - Answer: more true or false: fill the sample container completely full of water to be analyzed - Answer: false (needs headspace) get the sample to the lab within _____or it will be rejected - Answer: 30 hours possible causes of bad samples can be - Answer: improper flushing, soil entry during repairs, failure to disinfect new construction, careless sampling technique, cross-connections in the area In the event of distribution pressure below ___ psi, _______ outages, repeated bad samples or chlorine _____ below minimum, special precautions must be instituted. - Answer: 20/power/residual a by-product of chlorinated drinking eater, a suspected carcinogen when consumed in water over a lifetime - Answer: trihalomethane to prevent formation of THMS in surface water, chlorine is combined with ____________forming chloramine, combined chlorine residual - Answer: ammonia primary limits refer to chemicals with maximum contaminant levels that _____________be exceeded - Answer: can not at 8.0 to 1.0mg/L, flouride reduces dental cavities, but in higher doeses (>2.0 mg/L) can cause _____of teeth over time - Answer: mottling high nitrate or nitrite levels put infants at risk of - Answer: "blue baby" syndrome true or false: low doses of heavy metals such as lead, and copper can cause damage to the central nervous system over time - Answer: true the action level for lead is - Answer: 0.015 mg/L the action level for copper is - Answer: 1.3 mg/L the destruction of disease causing microorganisms - Answer: disinfection true or false: all public water systems must have chlorination facilities - Answer: true in addition to disinfection, chlorine is used to - Answer: remove taste, odor, and color in water, oxidize iron and manganese, control algae, and oxidize hydrogen sulfide gas in water the amount of chlorine applied in mg/L or ppm - Answer: dosage the amount of chlorine used p by inorganics (minerals) or organics - Answer: demand the amount of chlorine left after the demand is met - Answer: residual three types of residual - Answer: free, combined, and total The state requires within the distribution system a minimum chlorine residual of ___mg/L free or ___mg/L combined if ammonia is added - Answer: 0.2/0.5 DPD reacts with chlorine producing a pink to ____ color. - Answer: red utility operators use chlorine in three commercial forms: - Answer: pure chlorine in the liquid or gas state, bleach solutions, and granular/tablet compounds at room temperature chlorine is a greenish-yellow gas that is ___________ times heavier than air - Answer: 2.5 the maximum sustained gas withdrawal rate for presure transmission 150 lb cylinders is ____lbs/day - Answer: 40 hypochlorous acid is the disinfectant and the _________ residual - Answer: free Liquid bleach used in PWS must be ______ approved. - Answer: NSF the state requires _____ to be kept in stock for disinfecting new water lines - Answer: calcium hypochlorite primary components of a gas feed chlorinator include: - Answer: injector, flowrate controller, rotameter, and vacuum regulator The rotameter indicates the feed rate in _____ per day - Answer: pounds hypochlorinators consist of - Answer: mixing tank and chemical solution feed pump chlorinator rooms must be provided with facilities for determining the amount of disinfectant used ___________ - Answer: daily A full-face self-contained breathing apparatus or supplied air respirator must be readily accessible outside the ___________when chlorine gas is used. - Answer: chlorinator room If a major chlorine leak occurs, call the supplier and the _____. - Answer: TCEQ most leaks occur at the container valve and can usually be stopped by - Answer: closing the valve, tightening the packing nut, or applying the outlet cap with gasket over the outlet If chlorine enters the eyes, flush with running cool water for at least ___ minutes and seek medical attention. - Answer: 15 water in an aquifer is called - Answer: artesian water impermeable rock overlays ________aquifers - Answer: artesian a well drilled into a water table aquifer is usually a ___________well - Answer: shallow Wells dug into artesian aquifers are considered _____ wells. - Answer: deep porosity - Answer: the percentage of openings or pores within a formation permeability - Answer: the ability to transmit water through the aquifer no public well can be within ________ft of livestock, sewer lines, septic tank, storm sewers, or cemeteries - Answer: 50 No public well can be within ____ft of a septic tank drainfield, improperly constructed water well, or underground fuel or chemical tank - Answer: 150 a sanitary control easement covering land within _______ft of a public well must be recorded in county courthouse records - Answer: 150 Abandoned wells, not plugged, within ___ mile of a proposed well site must be reported to TCEQ. - Answer: 1/4 well casing - Answer: supports the bore hole and helps protect the aquifer from contamination the casing must extend atleast ____in above the floor of the pump room or ground surface - Answer: 18 the well screen prevents ________ from entering the well - Answer: sand in all cases TCEQ requires a concrete sealing block extending at least _______ft from the well casing in all directions - Answer: 3 the _____________ acts as a vacuum breaker - Answer: well casing vent true or false: TCEQ requires a faucet for raw water sampling on the discharge pipe of each PWS well - Answer: true TCEQ requires a ____________ on the discharge side of each well to measure yields for water production data - Answer: meter two types of well pumps in common uses are - Answer: line shaft vertical turbine and the submermisble driven by a motor located above the pump at ground level - Answer: line shaft turbine driven by a waterproof motor located under the pump - Answer: submersible pump static level - Answer: the water level in the well casing when the pump is off pumping level - Answer: the water level in the well casing when the pump is on drawdown - Answer: difference between static water level and pumping water level three ways to measure water levels - Answer: wetted tape, electric sounder, and the air line a bacteriological sample taken from a newly constructed well on ___________ successive days, must show negative results - Answer: 3 the state requires a physical and chemical analysis of the new well water after _____ hours of pumping - Answer: 36 the state requires wells be protected by - Answer: intruder-resistant fences or locked well houses ground water has _____ minerals and dissolved solids than surface water - Answer: more groundwater is usually clear and void of - Answer: bacteria most groundwater requires only ________, Mandated by the state - Answer: disinfection treatment for excessive mineral content includes: - Answer: softening, ion exchange, EDR, and RO Hydrogen sulfide gas can be removed by - Answer: an aeration process a type of polyphosphate can be used to ____ clear water iron before it is oxidized and becomes red, suspended iron - Answer: sequester treatment of corrosive groundwater can be accomplished by: - Answer: adding orthophosphates as caustic soda or soda ash to adjust the pH The Rio Grande River is the longest river in Texas, stretching __________miles along the Mexico border - Answer: 1250 largest lake entirely in texas - Answer: Sam Rayburn reservoir Raw water intakes must not be located within ________ ft of boat ramps, marinas, docks, or fishing piers - Answer: 1000 a restricted zone of __________ feet radius from the raw water intake must be established and recreational activities and trespassing shall be prohibited - Answer: 200 surface water is usually low in - Answer: minerals and gasses can be a problem in surface water as well as municipal, industrial, and agricultural pollution - Answer: bacteria, algae, and turbidity Complete Treatment as defined by TCEQ - Answer: Pretreatment disinfection, taste and odor control, continuous coagulation, sedimentation, filtration, terminal disinfection, and covered storage destratification - Answer: mixing of lake water by compressed air to prevent layers of different temperature from developing Certain types of organic matter cause algae to bloom and can result in taste and odor problems which are ______________to treat - Answer: difficult commonly used to treat iron and manganese - Answer: Chemical oxidizers (potassium permanganate) the primary goal of coagulation, sedimentation, and filtration is to remove _________ - Answer: turbidity true or false: turbidity can shelter bacteria From the disinfection process - Answer: true the two pathogenic protozoans resistant to chlorination are ___________and ___________ - Answer: giardia and cryptosporidium coagulation works by the bonding of __________ charged turbidity to ________charged chemical coagulants - Answer: negatively / positively Chemical dosage, water temperature, pH, _______, and the characteristics of the raw water all have an effect on the coagulation process. - Answer: mixing true or false: operators must run jar tests to select the most effective coagulant and dosage - Answer: true the process of separating floc from water by gravity is called - Answer: sedimentation true or false: most solids should be removed in the filtration step - Answer: true Filtration is the last barrier between the public and _______ or ________. - Answer: giardia/cryptosporidium TCEQ requires filtered water to be ____NTUs or less in at least 95% of measurements each month. - Answer: 0.3 filter problems include: - Answer: air binding, mudballs, media cracks and media loss if the media collects in the wash water troughs, the wash rate is too __________ - Answer: high All public water systems in Texas are required to use _____ as the final disinfectant. - Answer: chlorine treated water is stored at the plant in a tank called: - Answer: a clear well water is stored to meet peak demand and to allow production facilities to operate at _________rates - Answer: uniform Stored water can meet sudden demands such as fire, absorb pressure surges, provide detention/contact time for ________, and allow for expansion of the distribution system. - Answer: chlorination pressure from an elevated tank is caused by the height of the column of water in _________ - Answer: pounds per square inch true or false: the wider the column, the more pressure per square inch it will provide - Answer: false the primary advantage of elevated storage is that pressure is _____when supply pumps are off or electrical power is lost - Answer: maintained true or false: the diameter of the standpipe is greater than the height - Answer: false the water column must be at least _____ feet higher than the highest service connection to be considered elevated storage - Answer: 80 true or false: roof vents must be screened with 16 inch mesh or finer corrosion-resistant material - Answer: true all roof hatches must be _____ - Answer: locked true or false: ground water systems serving more than 50 connection must have a ground (total) storage capacity of 200 gallons per connection and elevated storage capacity of 100 gallons per connection or pressure tank capacity of 20 gallons per connection - Answer: true a ______________, internal, and documented inspection of al storage tanks is required - Answer: yearly potable water storage tank inspection results must be maintained at least ______ year(s) - Answer: 5 all community systems must post at each production and storage site a sign stating the name of the water system and _____________ - Answer: emergency telephone number true or false: an intruder-resistant fence with lockable gates must enclose the storage site - Answer: true The system must maintain a minimum pressure of ____ psi under normal conditions and at least _____ psi during emergencies. - Answer: 35/20 Pipe and fittings must not contain more than ____% lead or solder/flux containing more than ___% lead. - Answer: .25/0.2 true or false: meter designs include turbine, propeller, and compound, but a common design for residential service is the positive replacement meter - Answer: true a ______ valve is the most common isolating valve in the distribution system - Answer: gate true or false: a check valve located on the discharge side of a pump is an isolating valve that allows water to flow one direction only - Answer: true dead-end mains must be provided with - Answer: Flush valves Service tap components usually consist of a tapping saddle, corporation stop, service line tubing, curb stop and a _____. - Answer: meter when trenching, the spoil bank should be more than ____ feet from the excavation - Answer: 2 trenches or ditches ____ feet or deeper should be shored - Answer: 5 TCEQ requires at least 1 Bac-T sample for each ____ ft of new main - Answer: 1000 for a new main, hold a chlorine dose of ____mg/L or more for ____hours - Answer: 50/24 If a repaired main line must be returned to service quickly, dose it with ____mg/L Chlorine, for ___minutes. - Answer: 500/30 dead-end mains must be flushed at least ___________ - Answer: monthly close a fire hydrant slowly or a water ____ could occur - Answer: hammer corrosion results in tuberculation, a mineral buildup usually of oxidized __________ - Answer: iron backflow prevention measures include: - Answer: approved backflow prevention assemblies, vacuum breakers, and air gaps the ________is the operator's first choice to be used for backflow prevention when health hazards are involved - Answer: air gap common cross connections include: - Answer: a garden hose connected to a potable water source and submerged in a stock tank, a home served by a city water supply and private well, and a chemical container connected to a potable water supply The 2 primary categories of pumps are: ____ and _____. - Answer: centrifugal and positive displacement the force a pump works against is called ____ and is measured in feet of water or ___ - Answer: head/psi true or false: the total dynamic head a pump must overcome is the distance from the water level on the suction side of the pump to the top of the water level on the discharge side of the pump and includes any friction and head loss encountered - Answer: true A good safety program should have management leadership, employee participation, hazard identification, training, and ____________. - Answer: equipment true or false: Personal protective equipment is unlimited; it makes the wearer invulnerable to all injury - Answer: false The Texas Hazard Communication Act is know as the ___________ - Answer: "Right to Know Law" The Texas Hazard Communications Acts requires employers to provide Material Safety Data Sheets for hazardous _____ used in the workplace - Answer: chemicals True or false: Training in the use of hazardous chemicals must be repeated as needed - Answer: true To help safeguard against electrocution or machine injury, a safety program should have a ___________ policy. - Answer: lockout/tagout policy true or false: before digging, notify underground utilities - Answer: true Methods to protect workers from cave-in include: - Answer: sloping, benching, shoring, and shielding install all _____ from the top down and remove from the bottom up - Answer: shoring true or false: a competent person should inspect the cave-in protection at least daily - Answer: true The spoil should be placed no closer than _____ feet from the edge of the excavation - Answer: 2 A confined space is dangerous primarily because of the _____ - Answer: atmospheric conditions oxygen deficiency is considered to be less than ____% oxygen - Answer: 19.5 a confined space entry program should: - Answer: identify confined spaces, establish a permit system, train personnel, provide safety equipment and develop rescue procedures A confined space entry team consists of : - Answer: a supervisor, an attendant, and an authorized entrant The State allows utility works to use _______ control devices at work sites provided the devices conform to current manual criteria. - Answer: traffic For day or night work, a flaggers clothing should be: - Answer: orange, yellow, or green the STOP/SLOW paddle should be the _______ traffic control device - Answer: primary true or false: limit flag use to emergency situations and at locations controlled by a single flagger - Answer: true Generally, signs should be located on the right-hand side of the road and mounted on supports, posts, or __________ - Answer: barricades Barricade stripes must slope downward at ___ degrees in the direction the traffic is to pass - Answer: 45 flashing lights must be ______ and are excellent for attracting a driver's attention toward a potential hazard - Answer: yellow