ABC Field Test and Inspection Procedures 2

Question 1

When collecting a water sample for bacteriological analysis, what is the minimum flush time before sample collection from a chlorinated distribution tap?

Accepted Answer

2–3 minutes

Answer

Taps must be flushed 2–3 minutes to clear standing water and obtain a representative distribution sample.

Question 2

A Hach DR spectrophotometer reads a chlorine residual of 0.00 mg/L in a distribution sample. The first troubleshooting step should be:

Accepted Answer

Replace the reagent powder pillow and re-test

Answer

Depleted or expired DPD reagent is the most common cause of a falsely zero chlorine reading.

Question 3

What field parameter is used to estimate the carbonate-bicarbonate equilibrium and corrosivity of a water supply?

Accepted Answer

Langelier Saturation Index (LSI)

Answer

The Langelier Saturation Index indicates whether water will tend to deposit scale or corrode pipe materials.

Question 4

Which instrument measures the dissolved oxygen concentration directly without the need for chemical titration?

Accepted Answer

Membrane electrode DO meter

Answer

A membrane electrode (polarographic or galvanic) DO meter measures oxygen electrochemically in the field.

Question 5

During a wastewater effluent inspection, the inspector notices a persistent oily sheen on the receiving stream. The FIRST regulatory concern is:

Accepted Answer

Violation of oil and grease discharge limits

Answer

An oily sheen indicates a possible oil and grease permit exceedance and must be documented and reported.

(ABC) Association of Boards of Certification Practice Test

(ABC) Association of Boards of Certification Practice Test

ABC Field Test and Inspection Procedures 2