Overview
EN ISO 15175:2018 - "Soil quality - Characterization of contaminated soil related to groundwater protection" provides guidance on assessing soils and soil materials as potential sources of groundwater contamination. The standard focuses on contaminated land management, describing principles and main methods for site evaluation, monitoring strategies, sampling, and analytical approaches to understand how soils retain, release and transform contaminants that can affect groundwater.
Key topics and technical requirements
- Tiered assessment framework: a pragmatic approach from simple (Tier 1) to intermediate (Tier 2) and complex (Tier 3) evaluations to match effort with site complexity and risk.
- Site description and sampling: guidance on relevant sampling strategies and documentation needed to characterize soils, pore water, groundwater and soil gas.
- Soil processes and parameters: identification of key physical, chemical and biological processes controlling contaminant mobility (e.g., sorption, degradation, transport) and recommended parameters to measure.
- Analytical and monitoring methods: lists of analytical endpoints and methods appropriate for assessing contaminant concentrations in soil, soil water and gas, plus examples of complex assessment methods in annexes.
- Impact assessment and leaching risk: methods to evaluate direct and indirect inputs to groundwater, including substance transferability, concentration in soil water and degradation behaviour.
- Data quality and uncertainty: advice on sensitivity and uncertainty analysis, data handling and quality control to support robust decisions.
- Supplementary techniques: Tier 3 includes advanced biological, isotopic and geophysical parameters for complex investigations.
Practical applications and users
EN ISO 15175 is designed for practitioners involved in protecting groundwater from contaminated soils:
- Environmental consultants performing site investigations and risk assessments
- Regulators and public authorities setting investigation requirements or reviewing site characterisation reports
- Remediation and engineering firms designing soil management or remediation strategies
- Analytical laboratories advising on sampling and method selection for soil, pore water and soil gas
- Hydrogeologists and soil scientists assessing contaminant transport and attenuation
Use cases include preliminary screening of contaminated land, intermediate characterization to define remediation needs, and complex forensic studies to resolve pollutant sources and pathways.
Related standards
- ISO 5667 series (water sampling) - relevant for groundwater and pore water sampling guidance
- ISO 11074 (soil quality - vocabulary and properties) - terminology and property definitions
- ISO/TC 190 Soil quality documents - broader context for soil assessment standards
EN ISO 15175:2018 is a practical reference for implementing consistent, risk‑based soil characterization that directly supports groundwater protection and contaminated land management.