ABC Field Test and Inspection Procedures 5

Question 1

When inspecting a drinking water well, which condition is the MOST critical indicator of potential surface-water contamination of the aquifer?

Accepted Answer

Annular seal grouting that extends less than 18 feet below land surface

Answer

An inadequate annular seal allows surface water, including pathogens, to migrate directly into the well casing along the borehole.

Question 2

A flow meter at a wastewater plant effluent reads 2.8 MGD but the plant's rated permitted flow is 2.5 MGD. The inspector should FIRST:

Accepted Answer

Document the exceedance, notify the permitting authority, and initiate bypass protocols per the permit

Answer

Permit exceedances must be documented and reported to the regulatory authority; operators cannot alter meter readings to mask violations.

Question 3

What does the term 'CT value' represent in disinfection calculations?

Accepted Answer

Disinfectant concentration (mg/L) multiplied by contact time (minutes)

Answer

CT = concentration (C) × time (T) and is used to demonstrate adequate inactivation credit for pathogens under the SWTR.

Question 4

During a wastewater treatment plant inspection, the secondary clarifier shows a rising sludge blanket reaching the effluent weir. The MOST likely cause is:

Accepted Answer

Denitrification causing buoyant sludge or sludge bulking from low dissolved oxygen

Answer

Rising sludge in clarifiers is typically caused by denitrification gas lift or filamentous bulking from low DO in the aeration basin.

Question 5

An inspector must verify the accuracy of a magnetic flow meter in a water main. The most practical field verification method is:

Accepted Answer

Replacing the meter with a temporary ultrasonic clamp-on meter and comparing readings

Answer

A calibrated ultrasonic clamp-on meter installed adjacent to the magnetic meter provides a non-intrusive comparison without service interruption.

(ABC) Association of Boards of Certification Practice Test

(ABC) Association of Boards of Certification Practice Test

ABC Field Test and Inspection Procedures 5