4. Sampling

During drilling or after piezometer installation, sampling is a key stage in information gathering. The following four paragraphs describe sampling methods adapted to each medium: soil, soil gas, groundwater or free phase. The aim of any sampling campaign is to obtain a sample that is as representative as possible, at a given point in time, of the medium from which it is taken, in order to assess the quality of that medium.

Given the importance of sampling procedures for obtaining representative samples, Afnor has developed standards for detecting and characterizing pollution.

These standards cover the sampling of soil, soil gas and groundwater (see ).