AWWA Quality Control Procedures 2

Question 1

Which statistical tool is used to determine if a water treatment process is in a state of statistical control?

Accepted Answer

Control chart

Answer

Control charts plot process measurements over time to detect when a process drifts outside acceptable limits.

Question 2

What is the purpose of a blank sample in water quality analysis?

Accepted Answer

To detect contamination in reagents or equipment

Answer

A blank sample contains no analyte and reveals if reagents, equipment, or procedures are introducing contamination.

Question 3

Under the Safe Drinking Water Act, which agency sets maximum contaminant levels (MCLs) for public water systems?

Accepted Answer

EPA

Answer

The U.S. Environmental Protection Agency establishes legally enforceable MCLs under the Safe Drinking Water Act.

Question 4

A water utility collects duplicate samples to assess which component of data quality?

Accepted Answer

Precision

Answer

Duplicates measure precision by showing how closely repeated measurements of the same sample agree.

Question 5

What does the term 'method detection limit' (MDL) represent in water quality testing?

Accepted Answer

The minimum concentration reliably distinguished from zero

Answer

The MDL is the lowest concentration of an analyte that can be detected with 99% confidence that it is above zero.

(AWWA) American Water Works Association Practice Test