Class D Water Operator License Exam TCEQ 2024-2025. Questions and Verified Correct Answers, Exams of Water and Wastewater Engineering

Download Class D Water Operator License Exam TCEQ 2024-2025. Questions and Verified Correct Answers and more Exams Water and Wastewater Engineering in PDF only on Docsity!

Class D Water Operator License Exam TCEQ 2024-

2025. Questions and Verified Correct Answers.

Graded A

_______ is the last treatment step before storage. - ANSDisinfection _________ permits the owner of a well to pump as much water as desired, even if the water is drained from beneath the land of others. - ANSRule of Capture "Potable" means water is safe to drink and has a measurable chlorine ________. - ANSResidual A BacT sample, taken from a newly constructed well, on ____ consecutive days, must show negative results. - ANS A certain group of bacteria is used to indicate the possible presence of a pathogen--- the ________ group. - ANSColiform A common chemical used for disinfecting a small public water supply is: a) soda ash b) copper sulfate c) sodium hypochlorite d) fluoride e) sodium chloride - ANSc) sodium hypochlorite

A common type of oxidant that is used at most SW treatment plants to kill bacteria and to prevent trihalomethane formation is: a) total chlorine b) combined chlorine c) chlorine dioxide d) free chlorine e) ozonation - ANSb) combined chlorine A confined space entry team consists of a supervisor, an attendant, and an authorized _________. - ANSentrant A full-face self-contained breathing apparatus or supplied air respirator must be readily accessible outside the fire station when chlorine gas is used. - ANSFalse (A full-face self-contained breathing apparatus (SCBA) or supplied air respirator that meets OSHA standards shall be readily accessible outside the chlorinator room when chlorine gas is used.) A good safety program should have management leadership, employee participation, hazard identification, training, and ____________. - ANSequipment A potable water supply: a) is free of pathogenic organisms b) has an adequate chlorine residual c) contains a safe level of chemicals d) all of the above e) is found only in community type water systems - ANSd) all of the above

A PWS is responsible for providing: a) potable water b) adequate water pressure c) an adequate quantity of water d) all of the above e) soft water - ANSd) all of the above A restricted zone of ______ ft radius from the raw water intake must be established and recreational activities and trespassing shall be prohibited. - ANS A service area has 1000 service connections. What can we estimate the population of this service area to be? - ANS3,000 (multiply connections x 3) A well drilled into a water table aquifer is usually a ______ well. - ANSShallow Abandoned wells, not plugged, within ___ mile of a proposed well site must be reported to TCEQ. - ANS1/ According to state rules, all PWS wells must be provided with concrete sealing slabs, screened casing vents, raw water sampling taps and: a) liquid level indicators b) surge suppressors c) flow measuring devices d) fluoridation injection equipment

e) pressure gauges - ANSc) flow measuring devices All PWS in Texas are required to use ________ as the final disinfectant. - ANSchlorine An alkaline or basic solution has a pH greater than ____. - ANS An elevated storage tank should be protected against corrosion by: a) painting b) cathodic protection c) water stabilization d) all of the above e) galvanizing - ANSd) all of the above (painting, cathodic protection, and water stabilization) An intruder-resistant fence with lockable gates must enclose the storage site. - ANSTrue At 0.8 - 1.0 mg/L, fluoride reduces dental cavities, but in higher doeses (>2. mg/L) can cause _____ of teeth over time. - ANSmottling At room temperature chlorine is a greenish-yellow gas that is ___ times heavier than air. - ANS2. Before a new main is placed into service, it must be properly disinfected with a minimum chlorine dosage of:

a) 50 mg/L b) 30 mg/L c) 40 mg/L d) 75 mg/L e) 25 mg/L - ANSa) 50 mg/L Chemical dosage, water temperature, pH, _______, and the characteristics of the raw water all have an effect on the coagulation process. - ANSmixing Chlorinator rooms must be provided with facilities from determining the amount of disinfectant used _______ - ANSdaily Dead-end mains must be provided with ________ - ANSFlush valves Destratification is the mixing of lake water by compressed air to prevent layers of different __________ from developing. - ANStemperature Disinfection is the destruction of disease-causing microorganisms called ______. - ANSPathogens DPD reacts with chlorine producing a pink to ____ color. - ANSred Drought is an extended period when a region receives a deficiency in its ________ water supply. - ANSatmospheric, ground, or surface

Excessive calcium and _____ are the primary cause of hardness in water. - ANSMagnesium Excluding outside water use, the average household uses about _______ gallons of water per month for inside use - ANS2, Filtration is the last barrier between the public and _______ or ________. - ANSgiardia / cryptosporidium For day or night work, a flagger's clothing can be blue or brown. - ANSFalse Generally, signs should be located on the right-hand side of the road and mounted on supports, posts, or __________ - ANSbarricades Get the sample to the lab within ___________ or it will be rejected. - ANS30 hours (for BacT samples) Gravity filters will remove which of the following from surface water supplies: a) turbidity b) taste and odors c) nitrates d) hardness e) chlorides - ANSa) turbidity Groundwater is usually clear and void of __________. - ANSbacteria

Hypochlorous acid is the disinfectant and the _____ residual. - ANSFree If a major chlorine leak occurs, call the supplier and ______. - ANSTCEQ If a routine sample is positive, flush the positive sample point, check the chlorine residual, then resample within 24 days of notification. - ANSFalse (If a routine sample is total coliform-positive, the PWS should flush the positive sample point, check the chlorine residual, then resample within 24 hrs of notification) If chlorine enters the eyes, flush with running cool water for at least ___ minutes and seek medical attention. - ANS15 minutes If there is no chlorine ______ at a faucet, do not sample, flush longer. - ANSresidual If you added 3.5 mg/L of chlorine to your storage tank and 30 minutes later measured the residual at 1.2 mg/L, what was the chlorine demand in the tank? a) 4. b) 2. c) 0. d) 2. e) 4.7 - ANSd) 2. In Texas, agricultural water demand accounts for about ___% of the total water used. - ANS57%

In the event of distribution pressure below ___ psi, _______ outages, repeated bad samples or chlorine _____ below minimum, special precautions must be instituted. - ANS20/water/residual Install all _______ from the top down and remove from the bottom up. - ANSshoring Liquid bleach used in PWS must be ______ approved. - ANSNSF Meter readers bring in operating revenue and profoundly impact _____ relations.

• ANSPublic Monitoring average and maximum daily water ______ enables us to plan ahead for growth. - ANSDemand One part per million or 1 mg/L means that for every ____ pounds of water there is one pound of material in it. - ANS1 million Oxygen deficiency is considered to be less than ____% oxygen. - ANS19. Permeability is the ability to _____ water through the aquifer. - ANStransmit Pipe and fittings must not contain more than ____% lead or solder/flux containing more than ___% lead. - ANS0.25% 0.2%

Repeat samples must be taken at (a) the _______ ______ (b) within 5 connections upstream and (c) within 5 connections downstream. - ANSpositive point Service tap components usually include a tapping saddle, corporation stop, service line tubing, curb stop, and _______. - ANSmeter Solids, water hardness, pH and gases are ____ characteristics. - ANSChemical 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. - ANSchlorination Surface water is usually low in ________ and ________. - ANSminerals / gases Suspended solids in water cannot be filtered out. - ANSFalse (they can) T/F: A check valve located on the discharge side of a pump is an isolating valve that allows water to flow one direction only. - ANSFalse (it is a controlling valve) T/F: A Class "D" license is valid for 2 years at ground and purchase water systems with 250 connections or less. - ANSFalse (3 years) T/F: A competent person should inspect the cave-in protection at least daily. - ANSTrue

T/F: A confined space entry program should identify confined spaces, establish a permit system, train personnel, provide safety equipment and develop rescue procedures. - ANSTrue T/F: A distribution system without dead ends is called an open system - ANSFalse (looped system) T/F: A sanitary control easement covering land within 1500 feet of a public well must be recorded in county courthouse records. - ANSFalse (150 feet) T/F: All community and non-transient non-community PWS, regardless of source of water, must be under the supervision of a licensed water works operator. - ANSTrue T/F: All public water systems must have chlorination facilities. - ANSTrue T/F: All repeat samples must be collected on successive days. - ANSFalse (Collect all repeat sample on the same day) T/F: An example of a non-transient non-community PWS is a rural school. - ANSTrue T/F: Aquifers sandwiched between impermeable layers of rock or clay are called confined aquifers or artesian aquifers. - ANSTrue T/F: Bacteria, algae, and turbidity can be a problem in surface water as can be municipal, industrial and agricultural pollution. - ANSTrue

T/F: Barricade stripes must slope downward at 30 degrees in the direction the traffic is to pass. - ANSFalse (45 degrees) T/F: Before digging, notify underground utilities. - ANSTrue T/F: Bleach or alcohol require less contact time than flaming to disinfect a faucet. - ANSFalse (flaming requires less contact time) T/F: Chlorine reacts with hydrocarbons producing heat or fire - ANSTrue T/F: Close a fire hydrant slowly or a water log could occur. - ANSFalse T/F: Coagulation works by the bonding of negatively charged turbidity to positively charged chemical coagulants. - ANSTrue T/F: Common cross connections include 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. - ANSTrue T/F: Dosage is the amount of chlorine applied in milligrams per liter or parts per billion. - ANSFalse (parts per million) T/F: Duties of distribution operator include repairing leaks, making taps, flushing mains, and taking radiological samples. - ANSFalse (Repair leaks, Make taps, Flush mains, Operate pumps, Take bacteriological samples)

T/F: Examples of inorganic matter found in water include rock, sand, metals, and minerals. - ANSTrue T/F: Filtration is the first step in the removal of suspended solids. - ANSFalse (Sedimentation) T/F: Flashing lights must be yellow and are excellent for attracting a driver's attention toward a potential hazard. - ANSTrue T/F: Ground water supply systems serving more than 50 connections 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. - ANSTrue T/F: Hypochlorinators consist of a mixing tank and chemical solution feed pump. - ANSTrue T/F: If a repaired main must be returned to service quickly, does with 50 mg/L for 30 minutes. - ANSFalse (500 mg/L) T/F: If chlorine contacts the skin, flush with an emergency shower or garden hose for at least an hour. - ANSFalse (15 minutes) T/F: If the media collects in the wash water troughs, the wash rate is too high. - ANSTrue

T/F: If you do not fill out the submission form completely, you risk losing credit for the sample. - ANSTrue T/F: In 1978, the Texas Department of Health (TDH) assumed primacy over the Safe Drinking Water Act from the EPA. - ANSTrue T/F: In Texas, about 75% of all water is used for commercial, industrial, or agricultural purposes. - ANSTrue T/F: Keep the sample in ice or in a cooler prior to and during lab transport because heat stimulates bacterial growth. - ANSTrue T/F: Limit flag use to emergency situations and at locations controlled by a single flagger. - ANSTrue T/F: Low doses of heavy metals such as lead and copper can cause damage to the central nervous system over time. - ANSTrue T/F: Methods of fighting corrosion include coatings, temperature adjustment, and cathodic protection. - ANSFalse (pH adjustment, Orthophosphates, Poly-pigs) T/F: Most solids should be removed in the filtration step. - ANSFalse (Sedimentation) T/F: One by-product of chlorinated drinking water is trihalomethane, a suspected carcinogen. - ANSTrue

T/F: Only 3% of all the fresh water on earth can be easily accessed for use. - ANSFalse (only 1%) T/F: Only about 1 gallon of tap water per person/day is used for drinking and cooking - ANSTrue T/F: Pathogens are disease-causing microorganisms. - ANSTrue T/F: Powdered activated carbon (PAC) is commonly used to treat iron and manganese. - ANSFalse (removes the tastes and odors usually caused by dead and decaying algae and vegetation) T/F: Primary components of a gas feed chlorinator include an injector, flowrate controller, rotameter, and mixing tank. - ANSFalse (injector, vacuum regulator, flowrate controller, rotameter- not a mixing tank) T/F: PWS officials should be pro-active in their approach to terrorism. - ANSTrue T/F: Residual is the amount of chlorine left after the demand is met. - ANSTrue (Dosage: How much Cl you put in the system, Demand: How much Cl is used by the system, Residual: How much Cl is left over) T/F: Some artesian aquifer recharge areas (outcrop) are located many miles away from the well development site. - ANSTrue (Artesian Wells can be recharged from many miles away)

T/F: Taste and odor can come from organisms such as vegetation, bacteria, and algae, and from certain chemicals and metals. - ANSTrue T/F: TCEQ requires a faucet for raw water sampling on the discharge pipe of each PWS well. - ANSTrue T/F: TCEQ requires at least 1 BacT sample for each 1000 ft of new main. - ANSTrue T/F: TCEQ requires filtered water to be 0.3 NTUs or less in at least 95% of measurements each month. - ANSTrue T/F: The "primary limits" refer to chemicals with maximum contaminant levels that can be exceeded. - ANSFalse (refers to chemicals with maximum contaminant levels (MCLs) that CANNOT be exceeded.) T/F: The curb stop connects the main service line and the corporation stop isolates the meter for repair or replacement - ANSFalse (The corporation stop connects to the city main and the curb stop is used to isolate the meter for repair) T/F: The deeper the well, the warmer the water. - ANSTrue T/F: The difference between the static level and pumping level is call the drawdown. - ANSTrue T/F: The line shaft turbine is driven by a motor located above the pump at ground level. - ANSTrue

T/F: The most common design for residential service is the positive replacement meter. - ANSFalse T/F: The physical characteristics of water are color, taste, odor, temperature, and turbidity. - ANSTrue T/F: The presence of fecal coliform in a water sample indicates fecal contamination from a human or warm-blooded animal. - ANSTrue T/F: The primary state regulator of water utilities is the TCEQ. - ANSTrue T/F: The red color caused by iron is an example of suspended or apparent color and it can be removed by filtration. - ANSTrue T/F: The Rio Grande River is the longest river in Texas, stretching 250 miles along the Mexico border. - ANSFalse (1250 miles) T/F: The Safe Drinking Water Act sets standards for drinking water including physical, chemical, bacteriological, and radiological characteristics. - ANSTrue T/F: The State must be notified after an existing facility is changed or after construction of a new facility. - ANSFalse (must notify before) T/F: The State recommends 20 color units or less for a quality water. - ANSFalse (The state recommends 15 units of color or less for drinking water.)

T/F: The State recommends a maximum total dissolved solids content of 500 mg/L

• ANSFalse (The state recommends that TDS not exceed 1000 mg/L) T/F: The State recommends a water pH of less than 7 to be maintained at all time.
• ANSFalse (The state recommends a pH slightly greater than 7 and for the water to be non-corrosive.) T/F: The State requires a physical and chemical analysis of the water after 24 hours of pumping. - ANSFalse (36 hours) T/F: The term "total coliform" means fecal and non-fecal coliform. - ANSTrue T/F: The terms mg/L and ppm are not interchangeable. - ANSFalse (they are interchangeable) T/F: The Texas Hazard Communication Act is known as the "Right to Risk Law" - ANSFalse ("Right to Know") T/F: The Texas State Board of Fire Insurance requires utilities that provide fire protection to have a minimum amount of water available based on 30 gals per person per day. - ANSFalse (130 gals per person per day) T/F: The threshold odor number (TON) relates to the number of dilutions needed for the water to be tasteless. - ANSFalse (It reflects the number of dilutions needed for water sample to be odorless) T/F: 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. - ANSTrue T/F: There are 2 hydrogen atoms and 1 oxygen atom in each water molecule. - ANSTrue T/F: Training in the hazardous chemicals must be taken only once a year. - ANSFalse T/F: Treated water is stored at the plant in a tank called a clear well. - ANSTrue T/F: Treatment of corrosive groundwater can be accomplished by adding alkalinity as lime or soda ash to adjust the pH. - ANSTrue T/F: Turbidity can shelter bacteria from the disinfection process. - ANSTrue T/F: Turbidity must be limited because it shelters and nourishes bacteria and interferes with disinfection. - ANSTrue T/F: Utility operators use chlorine in three commercial forms:

1. pure chlorine in the liquid or gas state
2. bleach solutions
3. granular/tablet compounds - ANSTrue T/F: Well casing supports the bore hole and helps protect the aquifer from contamination. - ANSTrue

TCEQ defines "complete treatment" as the following sequence of processes: pretreatment disinfection, taste and odor control, continuous coagulation, filtration, sedimentation, terminal disinfection, and covered storage. - ANSFalse (1. Pretreatment disinfection

2. Taste and odor control
3. Continuous coagulation 4. Sedimentation 5. Filtration
4. Terminal disinfection
5. Covered storage) The _________ is TCEQ's first choice to be used for backflow prevention when health hazards are involved. - ANSair gap The action level for lead is _______ mg/L and for copper it is _____ mg/L. - ANS.015 / 1. The amount of chlorine in mg/L that is used up by reactions with organics and inorganics is called: a) dosage b) demand c) total chlorine d) residual e) free chlorine - ANSb) demand

The casing must extend at least ____ inches above the floor of the pump room or ground surface. - ANS The drawdown of a well is determined by: a) a properly installed air line b) the difference between the static and pumping level c) a psi gage calibrated in feet of water d) a tape measure e) an electronic sounder - ANSb) the difference between the static and pumping level The federal regulator of drinking water is the _____. - ANSEPA The least stable soil type is _________ - ANSType C The maximum sustained gas withdrawal rate for pressure transmission 150 lb cylinders is ____ lbs/day - ANS The pH of water indicates whether it is acidic or basic and is expressed by a scale of numbers ranging from: a) 0 - 7 b) 0 - 14 c) 1 - 7 d) 1 - 14 e) none of the above - ANSb) 0 - 14

The plant operator is responsible for a sufficient supply of safe and ________ drinking water. - ANSPalatable The primary advantage of elevated storage is that pressure is ___________ when supply pumps are off or electrical power is lost. - ANSmaintained The process of separating floc from water by gravity is called: __________ - ANSsedimentation The purpose of an air line on a well is to: a) aerate the well b) determine the depth of the aquifer c) inject chlorine into the well d) allow the well to breathe e) determine the water level - ANSe) determine the water level The purpose of the sample site plan is to assure bacteriological samples are collected from ______ service connections which are representative of the distribution system. - ANSactive The rotameter indicates the feed rate in _____ per day - ANSpounds The spoil should be placed no closer than ___ft from the edge of the excavation. - ANS2 ft

The State allows utility works to use _______ control devices at work sites provided the devices conform to current manual criteria. - ANStraffic The State recommends a TON of ___ or less. - ANS3 The State requires ________ to be kept in stock for disinfecting new water lines. - ANSCalcium hypochlorite The State requires filtered water to be equal to or less than ____ turbidity units in at least 95% of the monthly samples. - ANS0.3 The State requires wells be protected by ______-______ fences or locked well houses. - ANSIntruder-resistant The STOP/SLOW paddle should be the ______ traffic control device. - ANSprimary The system must maintain a minimum pressure of ____ psi under normal conditions and at least _____ psi during emergencies. - ANS35 / 20 The Texas Hazard Communication Act requires employers to provide Safety Data Sheets (SDS) for hazardous ______ used in the workplace. - ANSchemicals The two pathogenic protozoans resistant to chlorination are: ________ and _________ - ANSgiardia / cryptosporidium The well screen prevents _____ from entering the well. - ANSsand

There are 3 common gases found in water: methane, carbon dioxide, and __________ ___________. - ANShydrogen sulfide Three ways to measure water levels is the wetted tape, electric sounder, and the ______. - ANSairline (most often used) To help safeguard against electrocution or machine injury, a safety program should have a ___________ policy. - ANSlockout / tagout To prevent the formation of THMS in surface water, chlorine is combined with _____ forming chloramine, combined chlorine residual. - ANSAmmonia Water covers approximately ________ of Earth's surface. - ANS71% Water in an aquifer is called _____ water. - ANSground Wells dug into artesian aquifers are considered _____ wells. - ANSdeep When fecal coliform organisms are found in a water supply, it is an indication that: a) the water supply is contaminated b) pathogenic organisms might be present c) the water may be unsuitable for drinking d) follow-up sampling must take place e) all of the above - ANSe) all of the above

Which of the following is an acceptable level of residual chlorine in the far reaches of a distribution system? a) 0.2 mg/L of free chlorine for a small GWS b) 0.5 mg/L of chloramine for a large SWS c) 1.0 mg/L of combined when using ammoniation facilities d) 1.0 mg/L of total for a large SWS e) all of the above - ANSe) all of the above Which of the following is part of a hypochlorination system? a) solution feed pump b) gas cylinder c) rotameter d) injector/ejector e) all of the above - ANSa) solution feed pump Your ground storage tank is 15 feet high and 30 feet in diameter. About how much water can it hold? a) 31,700 gallons b) 79,270 gallons c) 50, 490 gallons d) 25,150 gallons e) 10,600 gallons - ANS...