California Wastewater Grade 4 Exam Prep FREE Sample Exam

An inspection lists a failed ventilation fan in a chlorine room and peeling paint in a break room, but funds cover only one job this month. What should the program do?

Repair the paint first because it is the cheaper and quicker job

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Split the funds so both jobs are partly completed this month

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Repair the ventilation fan first, because it controls a severe hazard, and defer the cosmetic work

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Defer both jobs until the next annual budget is approved

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A primary clarifier holds 412,000 gallons and the flow through it is 920 gallons per minute. How many hours of detention does the tank provide?

3.73 hours

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14.93 hours

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7.46 hours

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447.83 hours

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What does a routine microscopic examination program add to secondary process control?

An early warning: filament abundance and floc character can be seen trending before settleability and effluent quality deteriorate

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A replacement for settleability testing, which it makes unnecessary, and note the action in the shift log for the following crew to review

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A method for measuring the dissolved oxygen profile of the basin

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A count of the bacteria present that sets the wasting rate directly

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On afternoon rounds, a one-liter settleability sample drawn from an aeration basin settles to 310 mL after 30 minutes. The laboratory reports mixed liquor suspended solids of 2,400 mg/L for that basin. What sludge volume index do these results give?

12.92 mL/g

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77.5 mL/g

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129.17 mL/g

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155 mL/g

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An influent carries 27 mg/L of ammonia nitrogen that the plant fully nitrifies. How much alkalinity does nitrification consume?

124.20 mg/L as CaCO3

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96.39 mg/L as CaCO3

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27.00 mg/L as CaCO3

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192.78 mg/L as CaCO3

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Each backwash from one tertiary filter carries noticeably more media away than the backwash from its sister cells, and the bed level in that cell is falling month by month. What is the sound response?

Top the bed up to level on a fixed schedule and record nothing, because media loss at any rate is normal wear

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Investigate and correct the bed condition causing the loss — media loss is a recognized filter bed defect — instead of only replacing what was carried away

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Raise that cell's backwash rate further, because a stronger wash will settle the remaining media more firmly in place

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Lower the filtration rate permanently and accept the lost capacity, because a losing bed can never be returned to service, with the lost capacity written off in the annual report as a permanent reduction

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During a cold snap, gas production cannot cover both the digester boilers and the engine-generator. How should the gas be allocated, and why?

To the engine-generator first, because electricity production is the highest-value use of the gas in every season of the year

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Equally to both, because splitting a shortage evenly is the standard allocation whenever two uses compete for the same gas supply under an allocation rule the plant applies to every shared utility regardless of process criticality

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To neither, with all gas flared, because operating either use on a partial supply damages the equipment it serves

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To the boilers first, because holding digester temperature steady protects the methane formers, and generation takes what gas remains

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A plant will disinfect 0.48 million gallons of effluent at a dose of 6.2 mg/L using calcium hypochlorite that is 65% available chlorine. How many pounds of the product are required?

38.18 lb

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24.82 lb

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0.38 lb

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4.58 lb

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A long cold period is forecast for a pond plant that is already carrying a heavy load in its first cell. Which action applies seasonal capacity planning correctly?

Add the season's heaviest industrial load now, because cold water will preserve it until spring

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Wait for the effluent to fail, then judge from that single reading how much loading to remove, because a cold forecast alone never justifies changing a load

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Drain the first cell completely, because an empty cell insulates the remaining cells from the cold

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Trim and redistribute the loading ahead of the cold so the slowed biology is not asked to carry a summer load

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At a quarterly laboratory review, no single quality check has failed outright, but blanks have crept up, duplicate agreement has widened, and spike recoveries have drifted over three months. What is the program-level conclusion?

No action is warranted, because only an outright failure of a single check can ever justify a change

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Each analyst should be told privately to be more careful, with no change to methods or training made

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The quality checks should be run less often, so their trends stop suggesting problems that are not real, a step that will bring the blank, duplicate, and spike trends back into line without any change in how the work is done

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The drift across all three checks is itself the finding: the method or its execution is degrading, and retraining or a method fix is assigned before the drift produces failed results

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An effluent channel carries 11.25 cubic feet per second through a flow area of 3.0 square feet. What is the velocity in the channel?

3.75 ft/sec

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33.75 ft/sec

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0.27 ft/sec

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8.25 ft/sec

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Which description best fits supervision at the Grade IV level, beyond the shift-lead duties of assigning rounds and checking work?

Directing the laboratory's analytical methods in detail and approving each reported result personally before its release to the operating crew

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Program-level management: energy management, safety program development, operator training, and budget development and control

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Serving as the plant's purchasing agent for all of its chemicals, equipment, and contracted services

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Setting the discharge limits that the plant must meet under its waste discharge requirements

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California Wastewater Grade 4 Exam Prep FREE Sample Exam — Fixed Set

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