Technical Proficiency and Best Practices Flashcards
7 cards from real ABC practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Technical Proficiency and Best Practices flashcards as text
When calibrating a dissolved oxygen meter, which action ensures the most accurate reading before field use?
Answer: Allow the probe to air-equilibrate at ambient temperature and pressure
Air-equilibrating at ambient conditions accounts for local barometric pressure and temperature, ensuring accurate dissolved oxygen calibration.
A wastewater plant operator notices the return activated sludge (RAS) rate is too high. What is the most likely operational consequence?
Answer: Washout of mixed liquor suspended solids from the secondary clarifier
Excessive RAS flow can hydraulically overload the secondary clarifier, causing MLSS washout and poor effluent quality.
In a water distribution system, the purpose of a pressure-reducing valve (PRV) is to:
Answer: Protect downstream piping from excess upstream pressure
PRVs maintain downstream pressure within safe limits, protecting pipes, meters, and fixtures from overpressure damage.
Which safety practice is most critical when entering a confined space at a water treatment facility?
Answer: Testing the atmosphere for oxygen, flammable gases, and toxic vapors before entry
Atmospheric testing is the primary safety requirement before confined space entry to detect oxygen deficiency, flammable, or toxic hazards.
What does a high turbidity reading in treated drinking water most directly indicate?
Answer: Possible passage of pathogens through filtration
High turbidity in finished water suggests filtration inefficiency, which can allow pathogens including Cryptosporidium to pass through.
An operator observes a sudden drop in filter run time. Which of the following is the MOST likely cause?
Answer: Coagulation or flocculation process upset
Poor coagulation or flocculation results in poorly formed floc that penetrates and prematurely clogs filter media, reducing run time.
When collecting a bacteriological sample for compliance monitoring, the operator must:
Answer: Use a sterile container with sodium thiosulfate for dechlorination
Sodium thiosulfate neutralizes residual chlorine, preventing continued disinfection that would kill bacteria during transport and falsely lower counts.