ABC Field Test and Inspection Procedures 3

Question 1

When performing a coliform sample from a new water main before placing it into service, how many consecutive satisfactory samples are typically required by US regulations?

Accepted Answer

2

Answer

The Total Coliform Rule generally requires two consecutive satisfactory bacteriological samples before a new main is approved for service.

Question 2

Which test is performed in the field to quickly estimate the biological oxygen demand (BOD) trend without laboratory incubation?

Accepted Answer

COD rapid test

Answer

Chemical Oxygen Demand (COD) is a rapid surrogate that correlates to BOD and can be completed with field test kits.

Question 3

An operator notices the turbidity of filtered water has increased from 0.1 NTU to 0.45 NTU. Under the Surface Water Treatment Rule, the regulatory action level is:

Accepted Answer

0.3 NTU in 95% of samples per month

Answer

SWTR requires filtered water turbidity to be ≤0.3 NTU in 95% of monthly measurements for conventional filtration.

Question 4

What is the purpose of performing a chlorine demand test on a water sample?

Accepted Answer

To determine how much chlorine is consumed before a residual remains

Answer

Chlorine demand is the difference between the chlorine dose applied and the residual remaining after contact time.

Question 5

A wastewater inspector observes foam formation in an activated sludge aeration basin. The MOST likely cause is:

Accepted Answer

Excessive filamentous organism or surfactant presence

Answer

Persistent foam in aeration basins is commonly caused by filamentous bacteria (e.g., Nocardia) or surfactants in the influent.

(ABC) Association of Boards of Certification Practice Test

(ABC) Association of Boards of Certification Practice Test

ABC Field Test and Inspection Procedures 3