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

Pump motor temperature above ambient

Answer

Submersible pump rated below design flow

Answer

Pressure tank pre-charge below system pressure

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

Shut down influent pumps immediately

Answer

Add chemical treatment to reduce flow volume

Answer

Recalibrate the flow meter to match the permit limit

Question 3

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

Accepted Answer

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

Answer

Chemical treatment dose times turbidity

Answer

Chlorine residual times temperature correction factor

Answer

Contact tank volume divided by flow rate

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

Excessive return activated sludge (RAS) rate

Answer

High influent alkalinity

Answer

Over-chlorination of the effluent

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

Measuring pipe diameter and water velocity with a pitot tube

Answer

Checking the meter's firmware version against manufacturer specs

Answer

Testing the meter with deionized water

Question 6

What is the primary reason for collecting a field blank sample during a water quality sampling event?

Accepted Answer

To detect contamination introduced by the sampling equipment or process itself

Answer

To verify the lab's analytical accuracy

Answer

To measure background levels in the source water

Answer

To confirm the holding time is adequate

Question 7

Under the Lead and Copper Rule, first-draw lead samples must be collected after water has stood motionless in the plumbing for at least:

Accepted Answer

6 hours

Answer

30 minutes

Answer

12 hours

Answer

24 hours