Class B Groundwater Operator Exam

Successive raw-water analyses from a groundwater well show a meaningful upward nitrate trend. What is the most appropriate Class B operator response?

Increase well pumping rate because higher production will remove nitrate from the aquifer

Stop recording raw-water data so only finished-water results remain in the operating record

Verify the monitoring results and evaluate the source-water, compliance, and treatment implications of the trend

Ignore the trend until customers report a change in taste

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A pump delivers 850 gpm against 180 ft of total dynamic head. Pump efficiency is 75% and motor efficiency is 90%. Approximately how much motor input horsepower is required, ignoring service factor?

57.2 hp

28.9 hp

51.5 hp

38.6 hp

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A laboratory analyst dilutes 25.0 mL of a groundwater sample to a final volume of 250.0 mL. The diluted sample measures 18 mg/L of the analyte. What was the concentration in the original sample?

1.8 mg/L

18 mg/L

180 mg/L

1,800 mg/L

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A supervisor finds that different shifts document preventive maintenance on well pumps in different ways, making equipment history difficult to evaluate. What is the best corrective management action?

Standardize the maintenance record, assign responsibility, train the operators, and review compliance with the procedure

Stop recording preventive maintenance and document only complete equipment failures

Have only one employee remember the maintenance history instead of maintaining written records

Allow each shift to keep separate undocumented practices as long as the pump remains in service

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A public water system plans a significant modification to an existing well facility that will change production capacity. What regulatory action should occur before the modification is made?

Make the modification first, then notify TCEQ only if finished-water quality changes

Notify TCEQ and obtain the required approval, including plan review when required, before making the significant change

Proceed without TCEQ notification if the existing well permit remains unchanged

Obtain approval only from the licensed operator in responsible charge

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A main break causes distribution pressure to fall below normal. At a nearby facility, an unprotected hose connected to the potable system is submerged in a chemical solution tank. What is the principal public-health concern?

The submerged hose will prevent any reverse flow because liquid covers the hose end

The main break will automatically sterilize the chemical solution

Backsiphonage through the cross-connection can contaminate the potable system

The chemical tank will increase well specific capacity

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An experienced maintenance mechanic who is not a licensed water operator repairs a chemical-feed pump. The supervisor then proposes allowing the mechanic to independently change the treatment dose in response to water-quality results. What is the key licensing concern?

Independent treatment process-control duties require appropriate operator licensing unless a specific exemption applies

Licensing is unnecessary whenever a treatment adjustment is made during a maintenance shift

Licensing applies only to laboratory employees and never to treatment-process decisions

Anyone permitted to repair a chemical feeder may automatically make independent treatment decisions

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A groundwater sample is expected to have a pH near 7.7. Which two calibration buffers are the most appropriate for a two-point pH-meter calibration?

pH 4 and pH 7

pH 7 and pH 10

Distilled water and a pH 7 buffer

Two separate pH 4 buffers

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A groundwater system applies 3.2 mg/L chlorine and measures a 1.1 mg/L residual after the applicable reaction period. What is the chlorine demand under these conditions?

3.5 mg/L

0.34 mg/L

4.3 mg/L

2.1 mg/L

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A supervisor must verify two issues: whether a proposed modification to a public-water well facility meets Texas public-water-system requirements, and whether an employee is qualified to perform licensed process-control duties. Which pairing identifies the primary Texas rule chapters to consult?

Chapter 502 for both issues

Chapter 30 for the public-water-system issue and Chapter 290 for the licensing issue

29 CFR Part 1910 for both issues

Chapter 290 for the public-water-system issue and Chapter 30 for the licensing issue

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A vertical-turbine pump shaft begins spinning backward after the pump shuts down. Which component should the operator suspect first?

The laboratory pH electrode

The well vent screen

The discharge check valve

The raw-water sampling tap

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An operator is investigating groundwater stability and possible corrosion concerns. Which pair of routine water-quality measurements most directly describes acidity and buffering capacity?

Water level and chlorine-cylinder weight

Specific conductance and motor amperage

pH and alkalinity

Turbidity and pump discharge pressure

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A chloraminated groundwater system observes declining total-chlorine residual, increasing nitrite, and reduced ammonia in a low-turnover storage zone. What process should the operator investigate?

Well drawdown caused by excessive pumping

Nitrification

Hardness precipitation caused only by calcium

A pH-buffer calibration error that cannot affect distribution water

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Two equivalent production pumps operate in a lead-lag arrangement, but the same pump is always assigned as the lead unit. What operational change can improve long-term reliability?

Keep the lag pump permanently idle so it cannot wear

Close the discharge valve on the lag pump while it is running

Periodically alternate which pump serves as the lead unit

Disable automatic controls and operate both pumps continuously

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Raw-water hardness remains nearly unchanged, but after a corrosion-control adjustment raises finished-water pH, operators begin observing substantially more mineral scale. What is the best interpretation?

Scale can increase only if total hardness increases by the same percentage

The higher pH may have increased calcium-carbonate scaling tendency even though measured hardness remained similar

The increased scale proves that the well pump is operating below design horsepower

Chlorine residual is the only water-quality factor capable of producing mineral scale

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An operator suspects that a production pump is no longer delivering its historical capacity. Which combination provides the most useful direct operating evidence for evaluating the change?

Pump-room temperature and the number of customers billed that month

Only the elapsed-time meter without checking flow or pressure

Finished-water pH and the chlorine solution-tank level

Flow rate, discharge pressure, historical operating data, and the pump curve

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A groundwater well varies between 350 and 700 gpm, but its chemical feeder delivers nearly the same pounds per hour at all flows. Finished-water results are consistently high at low flow and low at high flow. What is the most likely control problem?

The chemical feeder is not being properly paced to the changing water flow

The aquifer is automatically increasing chemical concentration whenever the pump slows down

The feeder is correctly compensating for flow because pounds per hour should remain constant

The storage tank is increasing well drawdown at low flow

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A groundwater plant introduces a hazardous treatment chemical that employees have not previously handled. What should the supervisor ensure before employees begin routine work with the chemical?

Only the plant manager is given the safety data sheet because operators should follow verbal instructions

The chemical is used for several weeks before training so actual operating hazards can be observed

The original container label is removed after the chemical is transferred into plant inventory

Employees receive hazard information and training and can readily access the chemical safety data sheet

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A storage tank remains nearly full throughout the day, turnover is very low, and disinfectant residual leaving the tank is consistently lower than residual entering it. What operational change should be evaluated first?

Increase well drawdown because storage turnover is controlled by aquifer level

Close the tank outlet so no disinfectant can leave the tank

Keep the tank permanently at its maximum level so the water remains undisturbed

Adjust tank operation to improve turnover while preserving required storage and pressure

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What is the most useful purpose of a tailgate safety meeting before maintenance on groundwater-production equipment?

Review only production totals from the previous shift

Review the job-specific hazards, controls, protective equipment, and employee responsibilities

Assign the work first and discuss hazards only if an employee reports a problem

Replace written procedures with an informal discussion whenever the crew has performed the job before

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After changing to a new batch of treatment chemical, what should the operator do to confirm that the feed system is still delivering the intended dose?

Stop recording chemical usage until the new batch has been completely consumed

Assume the old feed rate is unchanged because the control dial has the same setting

Verify the chemical feeder calibration and actual feed rate

Increase the well pump discharge pressure until the chemical tank empties faster

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A chemical feeder starts whenever the well-pump motor starter is energized, but there is no device proving that water is actually flowing. What is the principal operational concern?

The arrangement eliminates the need to verify chemical-feed rate

Chemical could be fed into stagnant piping if the pump is energized but no water is moving

The feeder will automatically determine the correct dose from motor temperature

The arrangement will always reduce chemical concentration below the target dose

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A well normally pumps 600 gpm with a static level of 90 ft and a pumping level of 125 ft. During a prolonged dry period, the static level falls to 110 ft and the pumping level falls to 145 ft while flow remains 600 gpm. What is the best interpretation?

The pump efficiency has doubled because both water levels became deeper

The aquifer water level has declined while well drawdown at the stated flow remains essentially unchanged

The well screen has become completely plugged because drawdown doubled

The well is developing positive pressure and should immediately be throttled

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A groundwater plant uses the well flow meter to pace a chemical feeder. Tank-level measurements indicate that the actual well production has increased, but the indicated flow on the meter has not changed. What should the operator do before changing the chemical-feed setting?

Reduce the well-pump discharge pressure until the indicated flow matches the old value

Increase the chemical feeder to maximum output until the flow meter changes

Ignore the discrepancy because tank-level changes cannot provide useful operational information

Verify actual flow and check the flow-measuring system before changing the chemical feed

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Finished-water iron has increased significantly. The operator wants to determine whether the change originates in the groundwater source or in treatment performance. Which sampling approach provides the most useful initial diagnostic comparison?

Collect only a customer sample because source-water data cannot help distinguish a treatment problem

Measure only motor amperage because iron concentration can be inferred from pump load

Sample only the chemical solution tank because finished-water iron must originate in the feeder

Compare a representative raw-water sample collected before treatment with a finished-water sample under comparable operating conditions

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A newly constructed screened well continues to produce excessive fine sand, and its performance has not yet been established. Before selecting the permanent pumping equipment, what is the most appropriate sequence of actions?

Increase chlorination until the fine sand disappears, then select the permanent pump from the chlorine-feed rate

Develop the well to remove fines and stabilize the formation, then perform a yield-and-drawdown pumping test

Install the permanent pump first, then use customer demand to determine whether well development was necessary

Perform only a static-water-level measurement because well yield and drawdown should not be tested after development

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Well No. 1 produces 620 gpm for 14 hours in one day. Well No. 2 produces 480 gpm for 10 hours. Approximately how many million gallons do the two wells produce that day?

8.09 MG

0.809 MG

0.404 MG

1.10 MG

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A repair crew is scheduled to reenter a trench after a heavy rainstorm. What should the supervisor require before employees reenter?

A competent-person inspection and correction of any newly created hazards before entry

Only a check of the excavation depth because rainfall does not affect protective systems

Immediate entry if the trench was acceptable before the rain

Entry by one employee first to determine whether the trench still appears stable

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A groundwater plant relies on a chemical-feed process that must remain available for proper treatment. A single feeder failure would stop the process. Which improvement most directly increases treatment reliability?

Operate the feeder continuously at maximum output to reduce the chance of failure

Depend on customer complaints to identify when the feeder has stopped

Provide suitable feeder redundancy or critical spare parts and maintain the equipment preventively

Eliminate routine maintenance so the feeder is disturbed as little as possible

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A groundwater plant treats 1.80 MGD and needs a chlorine dose of 2.60 mg/L. Approximately how many pounds of chlorine are required per day?

65.0 lb/day

3.90 lb/day

39.0 lb/day

18.0 lb/day

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Raw-water alkalinity falls from about 180 mg/L as CaCO3 to about 45 mg/L as CaCO3 while other operating conditions remain similar. What operational consequence should receive particular attention?

The water has less buffering capacity and its pH may respond more strongly to chemical addition

The water automatically has four times as much hardness

The well pump will require four times as much horsepower

The chlorine demand must be exactly 135 mg/L higher

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A hydropneumatic system begins cycling its well pump much more frequently even though customer demand has not increased. Inspection shows unusually little air space in the pressure tank. What is the most likely condition?

The distribution system has developed excessive alkalinity

The tank contains excessive usable air volume

The well screen has necessarily become bacteriologically contaminated

The hydropneumatic tank is waterlogged

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A well historically produces 700 gpm with a static water level of 110 ft and a pumping water level of 145 ft. Several months later, the static level is still about 110 ft, but the pumping level at 700 gpm is 165 ft. What does this trend most strongly indicate?

The well is producing more efficiently because drawdown has increased

Well or pumping performance has deteriorated and should be investigated

The aquifer static water level has declined by approximately 55 ft

The change proves that the discharge flow meter is over-registering

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A vacuum gas chlorinator suddenly stops feeding chlorine. The chlorine cylinder contains product, but injector-water pressure has fallen substantially. Why can low injector-water pressure stop the gas feed?

The chlorine gas becomes nonreactive whenever water pressure decreases

Low injector pressure automatically closes the well casing vent

The injector may no longer create enough vacuum to draw chlorine gas through the feeder

The pressure change converts chlorine gas into calcium hardness

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Specific conductance from a well has historically been about 650 µS/cm but is now repeatedly near 1,050 µS/cm. After confirming instrument calibration, what can the operator reasonably conclude from this result alone?

The result proves that bacterial contamination is present

The result proves that nitrate alone has increased to an unsafe concentration

The result directly measures the chlorine residual in the well

The dissolved ionic character of the water has changed, but additional testing is needed to identify the cause

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A pressure zone has normal pressure at the pump station, but customers beyond a recently operated sectional valve report unusually low pressure and hydrant flow in that portion of the system. Storage level and pump discharge are normal. What should the operator investigate first?

Verify the sectional valve position and check for a localized restriction downstream

Increase disinfectant feed because low chlorine residual is the usual cause of reduced hydrant flow

Increase the well-pump pressure setting before checking the affected part of the distribution system

Lower the storage-tank operating level because high storage normally causes localized low pressure

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Why does a bacteriological sample bottle used for chlorinated drinking water normally contain sodium thiosulfate?

To raise sample turbidity so the laboratory can detect coliform organisms

To preserve pump lubricants that may be present in the sample

To neutralize residual disinfectant so it does not continue acting after sample collection

To increase chlorine demand so bacteria grow more rapidly during transport

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A well's pumping water level is currently 185 ft below the measuring point, and the pump intake is 200 ft below that point. Operators expect the pumping water level may decline another 20 ft during the dry season. What is the primary operational concern?

The additional decline would automatically increase the pump's available submergence

The static water level would necessarily rise by 20 ft at the same time

The change would affect only laboratory pH calibration and not well operation

The pumping water level could fall below the pump intake, causing loss of submergence or dry running

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Historical raw-water results show that iron and manganese concentrations from a well are increasing. What is the best Class B operational approach?

Immediately double every chemical-feed rate without checking finished-water results

Ignore raw-water changes as long as the well motor amperage remains normal

Confirm the analytical trend and evaluate treatment performance before making a controlled operational adjustment

Increase pump speed because higher velocity removes dissolved iron and manganese from groundwater

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A contact tank has 450,000 gallons of usable operating volume. The plant flow is 1.25 MGD. What is the theoretical detention time in the tank?

8.64 hours

2.88 hours

15.0 hours

0.36 hour

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A normally smooth-running well pump suddenly develops excessive vibration, unusual heat, and a burning odor. What is the best operator response?

Continue operating the pump until its discharge reaches zero

Remove the unit from normal service as appropriate and investigate the mechanical and electrical condition promptly

Reduce recordkeeping because the symptoms are normal signs of a loaded motor

Increase the pump speed until the vibration becomes less noticeable

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A Texas groundwater system using free chlorine measures 0.18 mg/L at the entry to the distribution system and 0.25 mg/L at a distribution monitoring site. Which statement is correct?

The entry-point residual is below the required minimum for free chlorine

Both values are acceptable because only the distribution sample is regulated

The entry-point result is acceptable whenever the distribution result is higher

The system must maintain at least 0.5 mg/L free chlorine at every location

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Why should deterioration of a groundwater well casing or grout seal receive prompt attention?

The casing and grout affect only electrical efficiency and not source-water protection

Deterioration normally improves recharge by allowing more surface water into the casing

The condition matters only when the well pump is physically removed

Deterioration can create a pathway for contamination to enter the well

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Operators hear a sharp pressure surge in the distribution piping whenever a large pump stops rapidly. Which corrective approach most directly addresses the hydraulic cause?

Increase the speed at which all major valves close

Use controlled pump transitions or appropriate slow-closing valve and timing controls

Increase chlorine dosage whenever the pump shuts down

Remove the pressure-relief and surge-control devices

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A well continues to produce approximately the same flow, but its pumping water level has gradually fallen farther below the static water level. What operating information should be trended to investigate the change most effectively?

Only the daily chlorine-cylinder weight

Customer meter readings without any well operating data

Only the finished-water storage level at midnight

Static water level, pumping water level, discharge rate, and drawdown over time

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Two waters have the same free-chlorine residual and contact time, but one has a substantially higher pH. All other important conditions are comparable. Why may free chlorine be less effective in the higher-pH water?

Higher pH eliminates chlorine demand regardless of water quality

Higher pH shifts more free chlorine from hypochlorous acid toward the less effective hypochlorite ion

Higher pH converts all free chlorine directly into dissolved oxygen

Higher pH prevents chlorine from reacting with water at all

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A pressure zone maintains normal pressure during average demand, but pressure falls sharply every morning while the supply pump runs continuously and storage level continues to decline. What should the operator evaluate first?

Whether the chemical feeder is using the correct pH buffer

Whether the bacteriological sample bottle contains thiosulfate

Only the color of the well casing

Peak demand compared with available pumping and usable storage capacity

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A turbidity result is unexpectedly high even though the sample appears clear, and duplicate readings vary widely. What should the operator do first?

Check the instrument and sample cell for calibration or measurement problems and repeat the test

Assume the well has failed because clear water cannot have measurable turbidity

Report the highest reading and discard the inconsistent duplicates

Immediately increase every treatment-chemical feed rate

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A Texas public-water-supply well has been reworked by cleaning and jetting. After the well is disinfected and the disinfectant has been flushed out, what bacteriological condition must be satisfied before the well is returned to service?

One distribution-system sample must be free of coliform organisms

Three successive daily raw-water samples must be free of coliform organisms

No bacteriological sampling is required after the disinfectant has been flushed

One raw-water sample is sufficient for every type of well reworking

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Before an employee enters a permit-required confined space, in what order should the atmosphere normally be tested for the principal atmospheric hazards?

Flammable gases and vapors, then toxic contaminants, then oxygen

Toxic contaminants, then oxygen, then flammable gases and vapors

The sequence does not matter as long as one atmospheric test is made

Oxygen, then flammable gases and vapors, then toxic contaminants

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