ISO 19258:2018

Overview - What ISO 19258:2018 covers

ISO 19258:2018, "Soil quality - Guidance on the determination of background values", provides international guidance for deriving background values for inorganic and organic substances in soils at a local to regional scale (site-scale excluded). It explains principles and main methods for sampling, sample pretreatment, laboratory analysis, data processing and statistical evaluation to produce comparable background concentrations that account for both pedo‑geochemical (natural) and anthropogenic (diffuse) contributions. The standard explicitly excludes groundwater and sediments.

Key technical topics and requirements

• Scope and definitions: Clear definitions of background concentration, pedo‑geochemical vs anthropogenic fractions, study area, variate and statistical characteristics (mean, median, percentiles).
• Objectives & technical approach: Guidance to define the “why” (regulatory baseline, soil protection, contamination assessment) and the “how/where/when” (substances, study area geometry, time period, scale of sampling).
• Evaluation of existing data: Minimum completeness and comparability checks for legacy datasets, assessment of metadata (sampling and analytical methods) and outlier examination.
• Collection of new data: Recommendations on sampling strategies at local/regional scales, handling, pretreatment and selection of analytical methods for both inorganic and organic substances.
• Data processing & statistics: Requirements for statistical evaluation, presentation and reporting of background values; includes treatment of outliers (Annex A) and examples of substances/parameters (Annex B).
• Quality control: Data handling, quality assurance procedures and traceability to ensure robust, defensible background values.
• Exclusions: Does not apply to groundwater or sediment background value determination.

Practical applications and users

ISO 19258:2018 is used to produce defensible baseline data and reference values for:

• Environmental assessment and monitoring
• Regulatory compliance and soil quality standards
• Contaminated land assessment and remediation planning
• Land reuse, excavation and waste classification
• Research in pedology, geochemistry and atmospheric deposition studies

Typical users:

• Environmental consultants and remediation specialists
• Regulatory agencies and policy makers
• Accredited soil and environmental testing laboratories
• Land‑use planners and waste managers
• Academic researchers

Related standards (if applicable)

• ISO 11074 - Soil quality: Vocabulary (normative reference used by ISO 19258:2018)

Keywords: ISO 19258:2018, soil quality, background values, soil sampling, pedo‑geochemical, anthropogenic, soil analysis, statistical evaluation, environmental assessment.