Which sampling approach is described as periodic for monitoring water quality?

Which sampling approach is described as periodic for monitoring water quality?

• A. Grab sample
• B. Composite sample
• C. Periodic grab sample
• D. Integrated sample

Answer: (C)

Periodic grab sampling means taking grab samples at regular, predefined times to monitor water quality. This approach gives time-based snapshots, letting you see how parameters change at set moments and identify patterns or events. It’s used when you want periodic data without continuous monitoring. A single grab sample captures just one moment; a composite sample combines many samples over a period to give an average, which can hide time-specific fluctuations; an integrated sample collects over a continuous interval to produce a time-weighted or flow-weighted average, smoothing out changes rather than preserving discrete time points.

Periodic grab sampling means taking grab samples at regular, predefined times to monitor water quality. This approach gives time-based snapshots, letting you see how parameters change at set moments and identify patterns or events. It’s used when you want periodic data without continuous monitoring. A single grab sample captures just one moment; a composite sample combines many samples over a period to give an average, which can hide time-specific fluctuations; an integrated sample collects over a continuous interval to produce a time-weighted or flow-weighted average, smoothing out changes rather than preserving discrete time points.