The rehabilitation of the COKERIE FLEMALLE site in Flemalle and Seraing

Transcription

1 Luis Salazar Building on yesterday s Wallonia to create Wallonia s tomorrow The rehabilitation of the COKERIE FLEMALLE site in Flemalle and Seraing

2 2

3 The expertise of SPAQuE driving the development of a logistics and SME platform at the site of a former coke-oven plant In 2001, SPAQuE was invited to look into the rehabilitation of the Cokerie Flemalle site. SPAQuE went on to compile and interpret the existing data and devised a sampling plan. Various measures were put in place and samples taken. Goal Cokerie Flémalle to establish how to rehabilitate the site. Hainaut Brabant Wallon Liege Samples taken Namur 559 soil samples; 169 groundwater samples; Luxembourg 3 free-phase product samples; 10 site soil gas samples; 22 air samples. Results of the soil and water analyses The soil and the groundwater were found to be highly contaminated. The analyses also revealed the presence of free-phase products (such as tar for instance). Some pollutants were found in concentrations of up to 1,000 times higher than permissible levels : cyanides; polycyclic aromatic hydrocarbons; monocyclic aromatic hydrocarbons (benzene); mineral oils; heavy metals; phenol. On the 22 December 2005, the Walloon Government tasked SPAQuE with the rehabilitation of the site as part of the Plan Marshall. In addition to mapping the various types of pollution encountered, SPAQuE factors in the location and the future designated use of the site to select the most appropriate rehabilitation measures. Situated close to motorway slip road, directly linked to the railway system and adjacent to an inland waterway, the Meuse river, the site is eminently suited to billet a trimodal logistic platform. 3

4 Rehabilitation in three stages Stage 1 : 8,500 tonnes of cyanide-containing soil cleared The first stage of the rehabilitation operations got under way in August In all, 8,500 tonnes of soil contaminated with cyanide were dug up in the north-western section of the site across a 3,500 m² surface area, down to a depth of 1.5 m to 3.5 m. The soil was transported to an accredit disposal centre where it was subjected to heat treatment. As from August 2009, the material extracted from the soil was separately sorted before being sent on to the most appropriate treatment or recycling plants. Only the slag has been stored in-situ for analysis, and if possible to be re-used. Stage 2 : 122,000 m³ of sorted and crush waste and slag Demarcation of the site s south-western section in consideration of the investigations performed around the site. In August 2009, SPAQuE started the rehabilitation of the raised area in the south-east of the site (above). The operations chiefly consisted of clearing the soil of construction rubble, old brickwork and industrial constructions still in place at the site. This second stage saw close to 122,000 m³ of slag being excavated across a 3.5 hectares surface area. This slag was then sorted and crushed before being stored in an impermeable zone, with each lot to be analysed and treated during the third stage of the works. The excavated area was backfilled using clean soil brought in from outside the site. 4

5 Stage 3 : Treatment of all polluted soil, i.e. 336,000 tons During the first stage of the rehabilitation operations in 2008, SPAQuE had removed part of the cyanidecontaining soil that pervaded the north-western section of the site. In 2012, during the 3 rd stage of the rehabilitation works, SPAQuE went on to remove the remainder of the cyanide-containing soil, representing around 9,500 tons, leaving the path clear to start the excavation of the contaminated soil. Two types of excavation works were made to take place : standard excavations down to a depth ranging from 60 centimetres to 5.5 metres; excavations of the hot spots ranging from 6.5 metres to 7.5 metres in depth. So-called terres bleues or blue soil, contaminated by cyanide, prior to the excavation operations. 18,000 tons of soil polluted with cyanide was cleared from the site. In addition to the cyanide-contaminated blue soil that was excavated and cleared during the first stage, SPAQuE also extracted major industrial constructions from the soil in the southern-east section of the site, as the last remaining vestiges of the former coke-oven plant. The slag excavated during the second stage had to be stored in windrows on areas that had first been made impermeable. 5

6 Hot spots The surveys showed up three hot spots that presented very high levels of benzene and naphthalene contamination. Free-phase products and a supernatant layer had to be recovered from the top of the water table filled with gravel from the Meuse river. The excavations conducted for these hot spots reached depths ranging from 6.5 metres to 7.5 metres. In order to keep the emanations from harmful volatile organic compounds during the excavations down to the bare minimum, several measures were put in place : deconstruction of the foundations and other remaining substructures across a 2 metres thickness; the excavations were continued on sheet piling so as to reach a depth of 7.5 metres; constant extraction of the volatile compounds emitted during the excavations with a special air duct, followed by the treatment of the recovered gases; all excavated soil was transported on lorry covered with tarpaulin and poured into an in land barge to be transported by waterway to accredited treatment centers. 6

7 Safety measures Given the magnitude of the pollution of these hot spots, stringent safety measures were put in place that applied to anyone working at or visiting the site. In addition to staples such as safety shoes, hard hats and hi-vis jackets, workers and visitors alike are required to wear gloves, a face mask and disposable coveralls. Moreover, an overall smoking and eating ban is in place at the site. Workers and visitors are required to step through a decontamination chamber each time they enter or leave the site. As it is, all plant and equipment at the job site, including the vehicles, are pressurised. Finally, all working areas are specifically tagged in compliance with regulations in consideration of the risks in place. What is more, pollution readings are taken at the job site. In doing so, dust particle quality readings are performed once a month and particle quantity readings twice a week. During excavations, a gas detector is constantly in operation at the site. Volatile pollutant readings are performed using a PID (photoionisation) detector twice a day around the earth works. The level of benzene and naphthalene is read using DRAGER tubes. Finally, spent charcoal and resin tube readings are also conducted. If, the limit values for benzene and naphthalene are observed to have been exceeded with these readings, supplementary measures have been lined up, which involve : covering up the areas concerned with dedicated tarpaulins; spraying on a special foam layer into the trenches or the dug up earth; covering up the excavation area with a confined air mobile tent. 7

8 A future logistics platform and a business park for small and medium-sized companies In early 2008, a private company came forward that showed an interest in using the site as the location for its logistics activities. In close consultation with the local authorities, a land development plan was devised that divided the site into two areas : a trimodal logistics area (6.5 hectares); a business park for small and medium-sized companies (SMEs) and office spaces (1 hectare). These SMEs and offices will be directly tied to the multimodal platform developed on the rest of the site and geared towards the local economic fabric. After rehabilitation comes development... SPAQuE is set to act as the project manager for the construction works. The infrastructure to be built, together with the land, will subsequently be sold to the private company that will operate the site. In doing so, SPAQuE will be able to apply the VAT ruling regime which will prevent the business from paying the VAT over the rehabilitation and construction works. The Cokerie Flemalle site, a future multimodal logistics platform. 8

9 Cokerie Flemalle : from a brownfield to a potent forwardlooking activity area Industrial heritage from 1922 to 1984 As from 1922, a battery of 45 coke-ovens was taken into operation in the eastern tract of the site. This number would go on to be expanded by a further 68 ovens in successive stages. In 1975, the ovens were decommissioned. From 1922 to 1947, the western section was occupied by a desulphurisation plant, a gas holder and an electrical power station. The site also has a dedicated storage section for the waste produced by the coke-oven plant. In 1947, a second coke-oven plant was built, consisting of 44 ovens. In 1984, the company named SA Espérance-Longdoz discontinued its operations at the site. Square surface area 7.5 hectares; territory of the municipalities of Flemalle and Seraing. Area plan industrial economic activities area. Activities coking; recovery and treatment of by-products from the distillation of pit coal. Most of the technical installations were dismantled in In 2005, the site was bought by SPAQuE as a derelict wasteland. Once the rehabilitation work has been completed, the site will be ready to billet a multimodal platform. Plant lay-out of the Cokerie Flemalle from October Archive, Maison de la Metallurgie et de l Industrie de Liege collection, MFC 19 G,

10 Developments in pictures

11

12 Boulevard d Avroy, 38/ Liège - Belgique Tél. : Fax : Publisher: Philippe ADAM - Boulevard d Avroy 38/ Liège Photos SPAQυE : Philippe Saenen Production : SPAQυE Press Relations Department Graphic design : Eurotop