Kármentesítési Konferencia - 2003. május 21.

The French approach to contaminated-land management, the remediation of an abandoned industrial polluted site (Salsigne) and the DIFPOLMINE Life-environment demonstration project
Patrick Jacquemin
ADAME, Franciaország

Since April 2003, France had no specific legislation concerning contaminated sites. The first law for managing the industrial polluted soil dates from 19 July 1976 (Environment permits for industrial sites). In the framework of a new law concerning Industrial Risk, dispositions are going to be adopted by the French parliament. Until now, national policy and measures to be applied are defined in circulars of the Ministry of Ecology and Sustainable Development (MEDD) to the Prefects (Government representatives in the departments). Two key documents are the circulars of the 3 rd of December, 1993 and 10 th December, 1999 defining major features of a national policy for contaminated sites.

Firstly, since 1993, two national inventories were developed by the MEDD. The first one is a survey of the past industrial activities (BASIAS/basias.brgm.fr) and the second one is an inventory of the potentially polluted sites which need a specific administrative action (BASOL/environnement.gouv.fr).

Secondly, the actions are generally developed in two steps :

ŕ The Preliminary Site Investigations and Simplified Risk Assessment (SRA), based on Preliminary Site Investigations to collect available information on the site and a first sampling campaign. The results form the basis of a SRA that is a score method. With this simple evaluation a ranking of the sites is done in three categories : Class 3 : “Low-risk“ sites ; Class 2 : sites to be monitored ; Class 1 : sites requiring detailed investigations.

ŕ The in-depth Site Investigations and Detailed Risk Assessment (DRA) aims at evaluating the impact of the polluting chemical substances on the identified targets : human, water resources or environment. Thus remediation objectives can be defined.

Whenever no more responsible party is identified or is able to pay, the Prefect has the authority to impose the realisation of such or such step (SRA, DRA, remediation). In the contrary case, the Prefect asks the MEDD to authorise the ADEME to intervene. This procedure is defined in the circulars of the 7th of June, 1996.

Salsigne is one of the largest gold mining area in Europe (situated in the south of France). This site has been active for 90 years. The activity is responsible for severe arsenic pollution of soils, sediments and waters in the Orbiel river. In 1999, the Prefect asked the ADEME to supervise the site, to study the pollution and to propose a remediation program. In 2000, the plant was cleaned-up from the waste that has been stored, to prepare its pulling down, which has been finished in march 2003.

In parallel, studies have shown that large quantities of mining waste have been dumped and that the soil is heavy contaminated by arsenic. The studies have supplied a solid knowledge of runoff water impacts. It has been shown that about 2.5 tons of arsenic is discharged annually in the Orbiel river. Runoff water from the site often causes the arsenic concentration in the river to rise from 40 µg/l to above 600 µg/l downstream of the site, mainly as the result of erosion. Runoff water contains mainly pollution in particle form in concentration up to 40 mg/l, which sediments in the river. It can be found during periods of strong rain. From this site-specific environmental problem description, it becomes clear that erosion control and water management are the key to the control of diffuse pollution.
The remediation project, which will cost about 15 millions euro contains two actions :

ŕ First, 600 000 m 3 of waste will be excavated and encapsulated.

ŕ Secondly, on the soil, phytostabilisation will be applied to reduce the transfer of pollution towards surface water.

For this second part of the project ADEME is associated with IRH Environment, the Limburgs Universitair Centrum (Belgium) and the University of Technology and Economics of Budapest (Hungary) in the DIFPOLMINE project (Diffuse Pollution coming from Mining Activities). The project has been selected by the European Commission as a 2002 Life Environment demonstration project.

As Europe has been a place of intensive mining activity during the last centuries, the aim of the project is to show that the methodology in Salsigne can be adapted to other cases, as in the Toka valley in the North of Hungary where a specific study will be carried out by the University of Budapest.

The project results will be presented in two seminars organised in France and Hungary in 2006 with the objective to widely disseminate the acquired knowledge.

Réf : The French approach to contaminated-land management – MEDD – BRGM – www.fasp.info