ISO 18400-104:2018

Overview

ISO 18400-104:2018 - Soil quality - Sampling - Part 104: Strategies provides guidance for developing site investigation and soil sampling strategies to collect reliable information on the average properties, variability and spatial distribution of soil properties. It covers sampling for chemical testing and other properties (e.g., physical), and applies both to material taken to a laboratory and to in‑field measurements. The document also summarizes the statistical and geostatistical principles needed to design representative and defensible sampling programs.

Key technical topics and requirements

• Investigation strategy and zoning: Guidance on planning overall site investigations, defining zones of interest, and selecting appropriate types of investigation (preliminary, exploratory, detailed, supplementary).
• Sampling objectives and scope: How to define objectives (average concentration, variability, presence of hot spots) and translate them into a sampling scope.
• Sampling approaches: Descriptions of judgemental, systematic, convenience, cluster and composite sampling and when to use each.
• Sample types and sizes: Considerations for disturbed vs. undisturbed samples, spot (single), cluster, spatial (composite) and selective samples; guidance on practical sample sizes and increment design.
• Statistical and geostatistical methods: Principles for determining number of samples, spatial correlation, uncertainty estimation and design optimization (explained in informative annexes).
• Hot‑spot detection and sampling patterns: Strategies for locating and characterizing small-scale anomalies and for designing grids, transects or adaptive sampling.
• Sampling depths and relation to groundwater: Guidance on selecting depths relative to contaminant distribution and groundwater profiles.
• Uncertainty, safety and timing: Managing sampling uncertainty, health/safety and environmental protection, and scheduling investigations.
• Informative annexes: Practical tools and examples on statistics, sampling patterns, uncertainty assessment, sample size determination, geostatistics and risk‑based strategies.

Practical applications and users

Who uses ISO 18400-104:2018:

• Environmental consultants and site investigators
• Remediation contractors and project managers
• Geotechnical and environmental engineers
• Analytical laboratories and quality managers
• Regulators, risk assessors and researchers

Practical benefits:

• Design defensible soil sampling plans for contamination assessment, background surveys, waste classification and remediation validation
• Optimize number, location and type of samples to reduce cost while meeting data quality objectives
• Improve interpretation of spatial variability and reduce sampling uncertainty using statistical and geostatistical guidance

Related standards

• ISO 18400 series (e.g., ISO 18400-204 soil gas, ISO 18400-206 biological)
• Groundwater sampling: ISO 5667-11, ISO 5667-22
• Geotechnical sampling and measurements: ISO 22475-1

Keywords: ISO 18400-104:2018, soil quality, soil sampling strategies, sampling plan, site investigation, soil testing, geostatistics, sampling uncertainty.