This document document provides guidance on the principles behind, and main methods for, the evaluation of sites, soils, and soil materials in relation to their role as a source of contamination of groundwater and their function in transporting, degrading and transforming contaminants. It is focussed on contaminated land management identifying and listing relevant monitoring strategies, methods for sampling, soil processing and analytical methods. The gui d ance p rovi d ed is applicable to the evaluation of the impact of contaminants on groundwater in relation to: çø drinking water quality; çø irrigation water quality; çø watering use; çø industrial use; çø natural base flow.