There is an obligation of investigation of soils at the moment of property transfer, on a periodical base or by closure of certain installations who can or could cause soil contamination.The authorities may also gather information as a result of its investigations into soil quality. The exploratory investigations include a limited investigation into the past history of the soil, as well as restricted sampling operations.
If these investigations indicate the presence of contaminating substances, the need for further soil investigation depends on comparison of the concentrations with soil remediation values. During a descriptive soil investigation the contamination will be characterised in detail and the risk for humans and ecosystems will be defined. The aim of this investigation is to give a description of the nature, quantity, concentration and origin of the contaminating substances, the possibility that these might spread, and the danger that human beings, plants and animals, as well as surface and groundwater, might be exposed to.
There is made a distinction in policy depending on the origin of the soil contamination. "Historical" soil contamination is contamination originated before the first Decree came into force; this is before 29th October 1995. "New" soil contamination originates after the Decree came into force.
The remediation of new pollution is, according to the Decree, required as soon as the soil remediation values are exceeded. With respect to historical contamination, the decision to remediate will depend on the actual danger to man and the environment (non quantified general criteria). So a risk-assessment aproach is followed in the descriptive soil investigation. The remediation actions are determined in a soil remediation project. The Public Flemish Waste Agency (OVAM) supervises the remediation operations.
The GIR is an inventory of all the parcels of which data are known at the OVAM. The GIR serves as a data base for policy decisions and also functions as an instrument to protect and inform potential buyers of contaminated sites.
The GIR is open to the public. The soil certificate, an extract of this register for a specified ground, gives all the information known by the OVAM.
In the Flemish Soil Decree a remediation obligation rests on the operator or the owner of the land where the pollution entered the soil. This means also that the obligation does not rest on the owner of the land contaminated by migration of contaminating substances from other property. If new contamination is concerned, the obligation exists automatically. In the case of historical contamination, the obligation only arises after the remediation order by the government.
The Flemish Soil Decree intoduced a non-retroactive strict liability rule and channelled the liability for the new contamination to those that caused the contamination. Recourse against other responsible parties is however possible. With respect to historical contamination, liability is determined by the rules in effect before the decree came into force.
The owner or operator of the land where the pollution entered the soil is not obliged to carry out the remediation if he can prove that he did not cause the contamination himself (by his fault or otherwise) and that when acquiring the property, he was not and should not have been aware of the pollution. In addition is the owner for historical contamination not obliged to carry out the remediation if he proves that the contaminated land was acquired prior to 1993 and was since then exclusively used for a non-professional use although he had prior knowledge of the pollution.