Class D Water License – Texas 2024-2025. Questions and Correct Verified Answers. Graded A, Exams of Water and Wastewater Engineering

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Class D Water License – Texas 2024-2025.

Questions and Correct Verified Answers.

Graded A

_____ allows uniform pump rates, supplies water for firefighting, and provides time for disinfection. - ANSStorage _____ and _____ and other minerals cause hardness in water. - ANSCalcium and magnesium _____ are underground, water-bearing formations yielding useful quantities of water. - ANSAquifers _____ can adapt to conditions that would kill a human. - ANSCockroaches _____ cause small particles in water to clot together forming floc, and this process, flocculation, forms larger particles that settle more readily. - ANSCoagulants _____ facilities equalize demand on the water supply. - ANSStorage _____ fecal matter entering a water supply transmits pathogens to healthy people. - ANSInfected _____ is a process that forces water through a membrane. - ANSReverse osmosis

_____ is a tank, usually steel, supported aboveground on a tower. - ANSElevated storage _____ is an electrochemical method of preventing corrosion of the interior of metal tanks. - ANSCathodic protection _____ is put into bacteriological sample bottles to dechlorinate the water. - ANSSodium thiosulfate _____ is the amount of suspended matter such as clay, silt, organic matter, and microorganisms in the water. - ANSTurbidity _____ is the final step in removing suspended matter and chlorine-resistant microorganisms. - ANSFiltering _____ is the force the pump works against. - ANSHead _____ must be notified about changes to public water systems involving water source, water quality, and health hazards. - ANSThe state _____ occurs inside the pump volute or casing and is caused by insufficient pressure on the suction side of the pump, which creates a vacuum and causes water vapor bubbles to form. - ANSCavitation _____ solves problems of taste, odor, red water, or bad samples. - ANSFlushing

_____ tests help the operator determine the chemical and dosage to apply. - ANSJar tests _____ valves cut off sections of a system. - ANSIsolating valves _____ water comes from rivers, lakes, and reservoirs. - ANSSurface _____ water means the water is free of disease-causing organisms, has a chlorine residual, and is safe for human consumption. - ANSPotable ________ is a buildup of oxidized iron, calcium carbonate, or other chemicals in mains. - ANSTuberculation _____% of public water systems use surface water. - ANS40% "Stuffers" sent to customers in billing statements may contain ________. a. departments to call for service b. explanations of utility policy c. a history of the utility d. tips on water conservation e. all the above - ANSe. all of the above A _____ is 1) large enough to enter and do work; 2) has limited or restricted entry or exit; and 3) is not designed for continuous occupancy. - ANSconfined space

A _____ is a physical connection between a public water supply, and 1) another supply of unknown or questionable quality, 2) any source that may contain contamination, 3) any water treated to a lesser degree. - ANScross connection A _____ is a tank resting on the ground that is greater in height than diameter. - ANSstandpipe A 100-lb container of calcium hypochlorite (65%) contains 65 lbs of chlorine and _____ lbs of lime. - ANS25 lbs of lime A common filter is the slow sand filter, having several layers of differently sized media. (true/false) - ANSfalse (the rapid sand filter) A common filter problem is ________, prevented by proper backwashing. - ANSmud balls A federal agency impacting the water utility industry is the _____. - ANSEPA A filter must be _____ when a head loss of 6 to 10 feet occurs. - ANSbackwashed A gallon of bleach containing 5.25% sodium hypochlorite contains about _____ lbs of chlorine. - ANS0.44 lbs A gallon of water weighs _____ pounds and 1 mg/L equals one ________. - ANSwater weights 8.34 pounds 1 mg/L equals one part per million

A maximum allowable slope of 45° and a run to rise of 1:1 is for soil type ________. a. stable rock b. class A c. class B d. class C - ANSc. class B A pH of _____ is neutral. - ANS7 is neutral A public water system provides the public with piped water for human consumption, serves at least _____ service connections, and regularly serves at least _____ individuals daily at least _____ days out of the year. - ANS15 service connections 25 individuals 60 days out of the year A sanitary control easement must cover land within ________ feet of a public well. - ANS150 feet A Self-Contained Breathing Apparatus (________) must be readily available for chlorine rooms. - ANSSCBA A system's filtered water must be ____ Nephelometric Turbidity Units (NTU) or less in at least _____% of the measurements taken each month, and no sample can exceed _____ NTU. - ANS0.3 NTUs

95%

1 NTU

A well may be developed by surging, overpumping, jetting, and ________. - ANSbackwashing Acute violations require public notification within 72 hours by radio and television using the words "Minor Health Concern." (true/false) - ANSfalse (it's a major health concern) After construction or maintenance of a storage tank, a _____ sample must be taken after filling the tank. - ANSbacteriological sample After contacting chlorine gas, wash in a safety shower or with ________. - ANSa garden hose After evaluation, confined spaces are designated as _____ or _____. - ANSpermit required or non-permit required All employees should be kept informed of utility plans and policies. (true/false) - ANStrue All public water systems are required to employ licensed operators even if the system only _____ treated water bought from another source. - ANSredistributes treated water

All public wells must be provided with a _____ sealing block, a meter, a screened vent, and a sampling faucet. - ANSconcrete An isolation valve is generally not used to _____. - ANSthrottle water flow Area = ____ x ____ - ANSlength x width Area of a circle = _____ x _____ x _____ - ANS3.14 x radius x radius As the force a pump works against increases, the capacity and efficiency ________. - ANSdecrease At room temperature, chlorine gas is greenish-yellow, has a pungent odor, is ________ times heavier than air. - ANS2. Average water use depends on temperature, rainfall, cost, supply, and economic level. (true/false) - ANStrue Backwashing should expand the filter bed by ________%. - ANS30 to 50 Before starting construction, the utility must submit engineering plans to the AWWA. (true/false) - ANSfalse (plans must be submitted to TCEQ) Before taking a bacteriological sample, you should _____. - ANSflush the service line

Benching is a type of sloping done by cutting stair steps in the trench wall while maintaining the maximum allowable ________. - ANSslope Besides disinfection, chlorine is used for taste and odor control and ________. a. oxidation of iron and manganese b. oxidation of hydrogen sulfide c. disinfection of repairs d. all listed - ANSd. all listed Bleach used in public water systems must be ________ approved. - ANSNSF Boat ramps, marinas, and docks should not be located within _____ feet of a water intake. - ANS1,000 feet Byproducts of chlorine reacting with dissolved natural organic matter (mostly plant life) are _____ and _____. - ANSTrihalomethanes (THM) and Haloacetic Acids (HAA). Calcium hypochlorite is made by reacting chlorine with ________. - ANSlime Calcium hypochlorite is not dry chlorine. Dry chlorine is pure chlorine, liquid or gas, containing less than _____ ppm water. - ANS150 ppm Calcium hypochlorite will cause explosions or fires if it contacts ________ material. - ANSorganic

Cave-in protection includes shoring, shielding, and ________. - ANSsloping Chain link fence material must leave a gap at the ground to trim grass. (true/false)

• ANSfalse Changes in well water levels or the volume of water produced can alert the operator to a drop in the water table, screen stoppage, or damage to the ________. - ANSpump Chemical characteristics of water include hardness, pH, solids, and ________. - ANSgases Chemically, water is made of ________. - ANS2 atoms of hydrogen and 1 atom of oxygen Chemicals used in disinfection are chloramine, chlorine, chlorine dioxide, and ________. - ANSozone Chemicals used to disinfect include chloramine, chlorine, chlorine dioxide and _____. - ANSozone Chlorination is the most important process in the production of ________ water. - ANSpotable Chlorinator rooms must have ________-level and ________-level screened vents. a. window/ceiling b. door/floor

c. high/floor d. low/window - ANSc. high/floor Chlorine and water make two acids: hydrochloric (HCl) and ________ (HOCl). a. hypochlorous b. hypochloric c. hyperclorous d. hydrachloric - ANSa. hypochlorous Closing a hydrant valve too fast can cause water ________. - ANShammer Coagulants are sodium aluminate, aluminum sulfate, ferrous sulfate, and sodium chloride. (true/false) - ANSfalse (sodium chloride is table salt) Color in a public water supply should be less than _____ units. - ANSless than 15 units Color in water can result from _____ or _____. - ANSmineral or organic matter Combustible gases include methane, hydrogen sulfide, and carbon dioxide. (true/false) - ANSfalse (carbon dioxide is not combustible) Common deep well pumps include the ________ and the vertical turbine. - ANSsubmersible

Common gases found in water include hydrogen sulfide, carbon dioxide, methane, and sodium chloride. (true/false) - ANSfalse (sodium chloride is table salt) Common pump problems include ________ and water hammer. - ANScavitation Complaints should be treated as "griping" and investigated as a last priority. (true/false) - ANSfalse Copper sulfate in dosages of ________ and approved algaecides control algae blooms. a. 10 to 50 mg/L b. 1 to 5 mg/L c. 0.1 to 0.5 mg/L d. 0.01 to 0.05 mg/L - ANSc. 0.1 to 0.5 mg/L Critical safeguards of a distribution system include a chlorine residual, adequate pressure, bacteriological sampling, and _____ control. - ANScross-connection control Deep wells are usually _____ wells. - ANSartesian wells Delinquent payment notices should be ________. a. tactful and tasteful b. mailed in an envelope c. businesslike d. all listed - ANSd. all listed

Detention time in sedimentation basins must be at least ________ hours to allow floc to settle. - ANS Detention time is calculated by dividing _____ by _____. - ANSTank capacity in gallons by flow rate Disinfection capacity for drinking water must be ________% greater than the highest expected dosage. - ANS50% Disinfection destroys disease-causing microorganisms called _____. - ANSpathogens Disinfection destroys pathogens without sterilizing the water. (true/false) - ANStrue Do not place a main into service until a bacteriological sample is tested with ________ results. - ANSnegative Do not work in a trench ________ feet or deeper unless it is protected from cave- in. - ANS5 feet Dosage is the amount of chemical applied, demand is the amount of chemical used up, ________ is the amount of chemical remaining after reacting with demand. - ANSresidual

Dose new mains with ________ mg/L or more of chlorine at least ________ hours. - ANS25 mg/L 24 hours Each water sample is tested for all waterborne diseases. (true/false) - ANSfalse (not all) EPA requires a water system to keep a copy of each consumer confidence report at least _____ years. - ANS5 years EPA requires any private, municipal, or industrial entity storing or using ________ pounds or more chlorine to have a chemical risk management program. a. 2, b. 2, c. 3, d. 3,500 - ANSb. 2, EPA requires community water systems to provide customers with a ________ report on the system's water quality. - ANSyearly Examples of community water systems include ________. a. municipalities b. municipal utility districts c. rural water supply corporations

d. mobile home parks e. all the above - ANSe. all of the above Excavation spoil must be kept at least ________ feet from the excavation. - ANS feet Excessive amounts of fluoride may cause ________ or staining of teeth. - ANSmottling Excessive nitrates in drinking water can cause ________ syndrome in infants. - ANSblue baby syndrome Factors affecting sedimentation are weight of the floc, ________, detention time, and short-circuiting. a. water temperature b. water velocity c. taste and odor d. a and b - ANSd. water temperature and water velocity Factors that make water more corrosive are low pH, dissolved oxygen, and ________. - ANSfree chlorine Fecal coliform live in the _____ of humans and warm-blooded animals. - ANSintestines

Feedlots, sewage treatment plants, and landfills must be at least ________ feet from a public well. - ANS500 feet Flushing reduces slime and scale buildup, reduces red water complaints, brings chlorinated water to contaminated areas, and removes ________ materials from the system. - ANSchlorine-reducing Follow up with a phone call or ________ to make sure everything is satisfactory. a. postcard b. email c. letter d. a and b - ANSd. postcard or email For chemical analysis, surface supplies are sampled ______ a year and groundwater is normally sampled every ______ years. - ANS1 time 3 years Future water supplies will become more plentiful according to the TCEQ. (true/false) - ANSfalse Gas chlorinators use a rotameter to meter chlorine in ________ or grams/hr. - ANSlbs/day Gases such as methane, carbon dioxide, and hydrogen sulfide are reduced by ________. - ANSaeration

Get bacteriological samples to the lab within _____ hours or they are rejected. - ANS Good treatment of employees includes fair wages, benefits, and ________ working conditions. - ANSsafe working conditions Ground storage at a surface water treatment plant is called a _____. - ANSclear well Groundwater is located above the earth's surface and tapped by wells. (true/false)

• ANSfalse (groundwater is below the surface) Groundwater usually contains more dissolved minerals and gases than surface water, but fewer ________. - ANSmicroorganisms Heat-sensitive pressure relief plugs in chlorine containers melt at about ________ degrees F. - ANS160 degrees F Hold an open bottle of ________% ammonium hydroxide under a suspected chlorine leak. - ANS10% Hydrogen sulfide is heavier than air, colorless, flammable, toxic, and has a ________ odor. - ANSrotten egg (unless you get a dose that's so heavy it numbs your sense of smell)

Hypochlorinators consist of a mixing tank, water, ________ hypochlorite, or ________ hypochlorite and a chemical pump. - ANSsodium hypochlorite calcium hypochlorite If a 30-inch diameter access opening is not provided in a storage tank, the primary roof access must not be less than _____ inches. - ANS30 inches If a ladder is used, it must extend at least ________ feet above the edge of the excavation and be within ________ feet laterally of anyone in the excavation. - ANS3 feet above 25 feet laterally If ground storage is the only storage, capacity must be _____ gallons per connection. Otherwise, total storage capacity (elevated storage included) must be _____ gallons per connection. - ANS200 gallons per connection 200 gallons per connection If the bacteriological sample from a storage tank is negative, more samples must be taken until two consecutive samples are positive. (true/false) - ANSfalse (if negative you're good to go) If the excavation is ________ feet or deeper, a means of exit must be provided. - ANS4 feet If the soil is previously disturbed, it is ________. a. stable rock b. class A

c. class B d. class C - ANSd. class C If water quality reports are attractive and easy to ________, they can build goodwill and trust with the customer. - ANSunderstand If you know the pumping level and the drawdown, how do you find the static level? - ANSSubtract the drawdown from the pumping level If you know the pumping level and the static level, how do you find the drawdown? - ANSSubtract the static level from the pumping level In a water table well, the cone of depression is a ________ area around the well. - ANSdewatered In case of leaks, the best source of help is the ________. - ANSsupplier In chlorinator rooms, ________ must be provided to determine the amount of disinfectant used and the amount remaining daily. - ANSscales In small water systems the operator is often _____, _____ and _____. - ANSmeter reader, repair crew and pump operator In storage tanks, each foot of water column produces _____ psi. - ANS0.433 psi

In Texas, all public water systems are required to have ________ facilities. a. ozonation b. chlorination c. softening d. trihalomethane - ANSb. chlorination In Texas, water operator licensing is administered by the _____. - ANSTCEQ In the event of low distribution pressure (below _____ psi), water outages, repeated unacceptable microbiological samples, or failure to maintain adequate chlorine residuals, special precautions must be instituted by the water system. - ANS20 psi In water systems using surface water (or groundwater under the direct influence of surface water) the MCL for total trihalomethanes is _____ mg/L and the MCL for HAA5 (haloacetic acids) is _____ mg/L. - ANS0.08 mg/L (THMs) 0.06 mg/L (HAAs) Install a _____ in a pump discharge line to prevent water from flowing back through the pump during shutdown. - ANScheck valve It is _____ public health risk if a positive fecal coliform repeat sample or a positive total coliform repeat sample follows a positive fecal coliform routine sample. - ANSan acute It is possible to have positive bacteriological samples removed from your record. (true/false) - ANStrue

Lime is applied to water to adjust ________. - ANSadjust pH or alkalinity Listen to special requests and seek solutions to oblige the customer within ________. - ANSutility policy Livestock and septic tanks must be no closer than ________ feet to a public well. - ANS50 feet Low _____ can cause water to be corrosive. - ANSpH Mains must be no closer than _____ feet, in all directions, from sewers or manholes. - ANS9 feet Maintenance crews can warn customers of service interruptions and provide signs and barriers to protect the public. (true/false) - ANStrue Material used in water line construction must meet OSHA specifications and should not affect the taste, odor, or quality of the water. (true/false) - ANSfalse (AWWA specifications) Meter readers are the persons with whom customers have the least contact. (true/false) - ANSfalse (meter readers often have the most contact) Meter readers can be ambassadors of goodwill. (true/false) - ANStrue

Methods for controlling taste and odor problems are _____, algae control, aeration, chemical oxidation, and activated carbon. - ANSlake destratification Minimum chlorine residuals of ________ (free) and ________ (combined) are required in the far reaches of the distribution system. - ANS0.2 (free) 0.5 (combined/total) Most groundwater is relatively free of suspended matter, but ________ can be a major problem in surface water. - ANSturbidity Most surface water is low in minerals, gases, and ________. a. algae b. turbidity c. dissolved solids d. bacteria - ANSc. dissolved solids No paint, coating, or wax containing _____ is allowed in storage tanks. - ANSlead No source of contamination is allowed within _____ feet of a public well. - ANS50 feet One bacteriological sample is required for each ________ feet of completed main.

• ANS1,000 feet

One of the causes of taste and odor problems is _____ and _____. - ANSalgae and bacteria One of the components of the Texas Hazard Communication Act is employee access to ________. - ANSSDS (formerly MSDS) One of the most important purposes of a public water supply is _______. a. swimming b. landscape watering c. car washing d. firefighting - ANSd. firefighting One way to reduce sand pumping is to _____ the pump rate and cycle more. - ANSdecrease Operators have a responsibility to provide drinking water that meets federal and state standards. (true/false) - ANStrue Operators must keep records of water usage, system pressure, sample results, chlorine use, repairs, and maintenance. (true/false) - ANStrue Organic matter includes ________. a. sand b. plants, animals and humans c. minerals

d. all listed - ANSb. plants, animals and humans OSHA classifies soil into four categories: ________ rock, class A, class B, and class C. a. hard b. stable c. soft d. sharp - ANSb. stable OSHA requires an anti-fall line if a portable ladder or ________ are not used. - ANSstairs Overpumping of groundwater can result in _____. - ANSsubsidence Overpumping of groundwater is called _____. - ANSmining Ownership signs must include the utility name and emergency phone number at each production, treatment, or storage site. (true/false) - ANStrue Physical characteristics of water are temperature, turbidity, color, taste, odor, and pH. (true/false) - ANSfalse (pH is a chemical characteristic) Place spoil banks at least ________ feet from the trench excavation. - ANS2 feet Plastic pipe must be NSF approved and have an ASTM pressure rating of at least _____ psi or a standard dimension ratio of _____. - ANS150 psi

dimension ratio of 26 Pressure from an elevated tank is maintained by the _____. - ANSheight of the water column Pressure inside a _____ tank is provided by air mechanically compressed against the water surface. - ANShydropneumatic tank Pretreatment includes lake destratification, control of algae, debris removal, presedimentation, aeration, ________, and activated carbon adsorption. - ANSchemical oxidation Prior to January 1, 2014, pipe and fittings containing more than 8.0% lead, or solders and flux containing more than 0.2% lead, are prohibited in a public water supply. (true/false) - ANStrue Private employers, such as contractors, must follow ________ excavation and trenching rules. - ANSOSHA Problems caused by _____ are declining water levels and subsidence. - ANSoverpumping Public relations (PR) is the relationship between YOU, the water utility employee, and the _____. - ANScustomer Public water systems are required to compile a monthly report showing ________. a. rate increases

b. accidents c. dates of dead-end flushing d. disciplinary action - ANSc. dates of dead-end flushing Public water systems include cities, municipal utility districts, rural water supply corporations, mobile home parks, and _____. - ANScampgrounds Quality water has low amounts of color, turbidity, solids, and ________. a. oxygen b. taste and odor c. hydrogen d. all listed - ANSb. taste and odor Red water caused by oxidized iron is in suspension (apparent color) and cannot be removed by filtering. (true/false) - ANSfalse Removing _____ from water also helps reduce pathogens that may cling to the particles. - ANSturbidity Repairing a leak under some pressure has an advantage of ________. - ANSreducing contamination risk Select pipe on the basis of strength, length carrying capacity, durability, ease of installation, availability, soil conditions, and cost. (true/false) - ANSfalse (length shouldn't be a consideration)