At the end of November, the ISPRA (Italian Institute for Environmental Protection and Research) announced the publication of the “Guidelines on the monitoring of soil gas”. This document was eagerly awaited and it is the result of the work of ISPRA and ARPA (Italian Regional Agency for Prevention and Environmental Protection) within the activities of the Working Group 9 of the SNPA (National System for the Protection of the Environment), which defined and tested the procedure for control bodies to validate data deriving from the direct measurements of soil gas and field data, in the field of remediation procedures.
The sampling of the soil gas has different purposes to support of the remediation of contaminated soils:
- define the extent of the polluting source,
- identify the correct sampling points for water and land,
- assess the risk of inhalation of vapors,
- verify the effectiveness of remediation technologies.
On the contrary, the measurement of surface emissions of gases and vapors migrating towards the atmosphere are carried out in the same areas of reclamation but for assessing the risk of inhalation of vapors: the detection of contamination allows a prompt response by blocking the expansion of polluting volatile compounds.
The debate on which are the most appropriate techniques for the measurement of soil gas and the various regional protocols concerning the intrusion of vapors and the use of soil gas measurements is well-known. As these protocols often adopt different procedures in the use of methods and tools, it is thus necessary to outline a joint procedure. It is thanks to the experiments of the working groups and the experience gained by the scientific institutes and by control bodies that the guidelines for this type of monitoring can be drawn up and updated.
The documents produced by Working Group 9 have to be considered as the technical support for the Agencies and public and private sector operators for the following purposes:
- provide national technical indications for the design of experimental surveys on soil gas (soil gas survey, flow measurements) as part of the remediation procedures,
- define a national operating procedure for the use of data stemming from experimental measurements of soil gas in the Risk Analysis of contaminated sites.
Mérieux NutriSciences has participated in some sampling campaigns of the Working Group for the parallel measurement of soil gas and vapor flow with flux chamber (of different types) and ambient air. Experimental campaigns for techniques comparison and the harmonization of national guidelines enable us to trust that samples are meaningful and representative, a safe starting point for sound reasoning when assessing test results.