Industrial Park Remediation in Aviles

Abstract

Asturias has traditionally been a region with a primary industry based economy that, to a large extent, developed around mining and the iron and steel industry. Consequently, the areas where such production activities were implemented have been subject to a high contamination potential, accentuated by the fact that the factories were located on quaternary soils, very sensitive to pollution, on which anthropic fill materials from the local industries were dumped. Over the years, old factories have been dismantled, leaving a legacy of contaminated soils, many of which, when released by the original production activity, have been occupied by new companies, as is the case with a large number of the existing industrial parks. In some cases the growth of the cities leads to an increasing demand for building land, with the result that the lands have been used for residential purposes. This situation is further aggravated by the limited land availability in the region, owing to a large extent to its abrupt orography.

The dismantling of the installations configuring the front‐end facilities of Empresa Nacional Siderúrgica de España (ENSIDESA) led to the segregation of 1,650,000 square metres in August 1997. This land was allo-cated to the creation of a new industrial park, as well as an auxiliary area to complement the Avilés port facilities.

After analysing the contamination existing in the area, an assessment was made for determining the possible risks it entailed for the new intended use of the land. As a result, 22,000 tonnes of soil affected by dumping, spillage and leakage of hydrocarbons were removed, together with 2,500 tonnes of soil contaminated with polychlorobiphenyls (PCBs).

In order to prevent the contamination from spreading, the material removed was classified and stored in an area close to the port, while awaiting the decision on the best treatment to be applied. The treatment finally selected was the process known as thermal desorption, to be carried out with mobile equipment that would operate in the area where the contaminated soils were stored.

The treatment lasted from December 2002 to May 2003, mainly due to the fact that after regenerating the hydrocarbon‐polluted material, the treatment plant was modified to make it suitable for the recovery of the PCB contaminated soils. It was the first time such a process was applied in Spain. The target levels defined for contaminated soil remediation were achieved, and the soils thus regenerated were used as a basis for the foundations of various industrial units built in the park.

Keywords:

• Contaminated soil
• soil remediation
• thermal desorption
• brownfields
• PCB treatment