ISO 5667-24:2016

Overview

ISO 5667-24:2016 - Water quality - Sampling - Part 24: Guidance on the auditing of water quality sampling - provides a structured audit protocol to verify conformity with declared or assumed sampling practices. The standard covers the systematic assessment of field sampling procedures from the development of a sampling manual through sample delivery to the laboratory. It is applicable to environmental monitoring, potable water (source to tap), wastewater discharges, industrial and commercial water uses, power generation, and stored/containerized supplies. ISO 5667-24 excludes emergency chemical/microbiological incidents, radiochemical incident investigations, and calibration/maintenance of on-site test kits (see BS 1427 for field kits).

Key topics and technical requirements

The standard guides auditors on planning, executing and reporting water quality sampling audits, with emphasis on:

• Audit objectives: internal vs external audits and defining scope and priorities.
• Identification of critical factors: operational steps, audit prioritization and unscheduled observations.
• Risk-based vs judgement-based auditing: approaches for targeting audits according to risk.
• Document auditing: sampling manuals, programme documents, training policies, chain-of-custody, labels and record sheets.
• Real-time/field assessment: observation protocols, photographic evidence, temperature control monitoring and handling of nonconformities.
• Audit plan design and methodology: pre-audit questionnaires, staff competence, supervision, equipment, sample tracking and QA/QC linkages (see ISO 5667-14).
• Reporting and closure: preparing audit reports, statements of findings, recommended actions and closure meetings.
• Informative annexes: Annex A - audit forms; Annex B - temperature control procedures; Annex C - measuring uncertainty associated with sampling practices.

Practical applications

• Ensures consistency and traceability of water sampling programs.
• Verifies conformance to an organization’s sampling manual and national/regulatory requirements.
• Improves sample integrity (chain of custody, temperature control, handling).
• Identifies training needs, equipment shortfalls, and procedural gaps.
• Supports accreditation, regulatory compliance, dispute resolution and quality assurance in monitoring networks.

Who should use ISO 5667-24:2016

• Water utility auditors and quality managers
• Environmental agencies and regulators
• Laboratory QA managers receiving field samples
• Consultants and third‑party auditors performing compliance audits
• Industrial / power generation water managers and bottled water suppliers

Related standards

• ISO 5667 series (Parts 1, 3, 5, 10, 11, 14, etc.) - guidance on sampling design, preservation, specific matrices and QA/QC.
• BS 1427 - field water test kits (referenced for on-site kit use).

Keywords: ISO 5667-24, water quality sampling audit, sampling manual, audit protocol, field assessment, chain of custody, temperature control, sampling uncertainty.