Which of the following describes how field sampling frequency should be documented?

• A. Document sampling frequency for each load or per project requirements.
• B. Sampling frequency is optional and not recorded.
• C. Document sampling frequency monthly only.
• D. Document sampling frequency in a central report monthly.

Answer: (D)

Documenting field sampling frequency in a central monthly report creates a single, authoritative record that’s easy to review, audit, and reference over time. This centralized approach ensures everyone uses the same frequency, makes trends and changes visible, and supports consistent QA and regulatory compliance across loads and projects. When sampling frequency is kept in a central monthly report, it avoids fragmentation from recording per load or project separately, reduces the risk of gaps if records are optional, and aligns with regular reporting cycles so stakeholders can easily monitor how often sampling occurs and adjust as needed.