Soil analysis and sampling are important in contaminated sites to verify their degree of contamination, and in uncontaminated areas to verify the possible reuse of the soil obtained by excavation works.
Soil analysis plays an extremely important role in environmental investigations aimed at the characterization of sites for commercial/industrial use, but also for residential/public-private green areas, thus conditioning the construction of infrastructural works or the startup of land reclamation or disposal activities.
Soil: What is contamination?
A site is contaminated when, due to previous or ongoing human activities, an alteration of the qualitative characteristics of the soil has been ascertained and poses a risk to human health.
The investigation includes chemical and biological analysis of organic and inorganic compounds, including pesticides, heavy metals (such as zinc, cadmium, chromium, etc.), BTEX, PAH, phenols, PCDD/PCDF, and PCB, as well as granulometric curves and soil geotechnical classification. For example, tests are often carried out in soils that housed industrial sites to assess their levels of contamination and to establish the reclamation plan.
Soil contamination: many important analyses to take into consideration
Contaminants alter the properties of soil and sediments, thus making them less suitable to host plants and animals and creating situations of danger for humans and other living organisms.
Analytical surveys on soils, through high-quality test protocols, allow decisions to be taken based on scientifically defensible data for the protection of the environment and the protection of citizens’ safety. The tests support the management of the risk analysis and guarantee full comparability with the checks performed by relevant control bodies.
The main soil analyses are:
- Analysis of excavated land and rocks
- Sediment analysis
- Analysis of samples from surveys, trenches, and the excavation bottom
- Soil interstitial gas analysis
- Granulometric curves and soil geotechnical classification
- Evaluation of soil chemical aggression against concrete
- Analysis of sludge, residues, and compost to be used in agriculture
In some cases, during site-specific risk analyses, some physical determinations, such as geotechnical determinations, may also help. Mérieux NutriSciences performs the following geotechnical tests according to UNI CEN ISO/TS 17892:
- Water content (W)
- Attemberg limits
- retained fraction at 0.4 mm
- liquid limit (wL), plastic limit (wP), plasticity index (PI), liquidity index (LI), consistency index (CI)
- relationship between water content and penetration of the conical tip
- density in the anhydrous state (core drilling), density in the wet state (core drilling), mass of the granules (pycnometer)
- granulometric distribution (curve) and effective porosity
