TractorsTask: making polluted soil suit­able for cultivation again

Although very well-regu­lated in France, the trans­porta­tion of hazardous mate­rials is not immune from acci­dents with regret­table conse­quences. This was the case on 19 July 2023 in the depart­ment of Tarn-et-Garonne, when a tanker trans­porting 30,000 litres of diesel and 4,000 litres of premium-grade petrol over­turned. The Véolia group was tasked by the author­i­ties with decon­t­a­m­i­nating a hectare of agri­cul­tural land adja­cent to the road. The company Dieuzaide TP and its two fuel-effi­cient John Deere trac­tors helped with this job.

Decon­t­a­m­i­nating the soil: What tech­niques were used?

Véolia recom­mended studying the site before­hand to iden­tify the pollu­tion and assess the risks. Several sophis­ti­cated decon­t­a­m­i­na­tion tech­niques were possible for the site.

• Injecting air under pres­sure (venting or sparging) to bring volatile pollu­tants to the surface
• Pumping ground­water (strip­ping) to bring dissolved pollu­tants to the surface
• Chem­ical oxida­tion through the injec­tion of chem­ical reagents into the soil, enabling decom­po­si­tion of the pollu­tants
• Simul­ta­neous extrac­tion and treat­ment of pollu­tants contained within the soil and ground­water (slurping)
• Stabil­i­sa­tion by reducing the mobility of pollu­tants within the soil

In the case of the acci­dent at Bouillac, Véolia opted for a simple solu­tion spread over several months. Initially, Dieuzaide TP was chosen to clear a 50cm thick layer comprising the entirety of the polluted surface. This amounted to 1,000t of earth in total. An exca­vator oper­ated by Foued Ehlgaz, a driver for Dieuzaide TP, and an assembly consisting of a John Deere 6R185 tractor with a 20t dump trailer, oper­ated by Joël Nerocan, were used for this task.

Each load was trans­ported to large containers nearby. They were diluted with large quan­ti­ties of compost and checked peri­od­i­cally. When the Véolia experts deem it free from pollu­tion, the soil will be returned to where it came from for agri­cul­tural use.

Focus on Dieuzaide TP

“I went into busi­ness in 2006, when I left school, with a brush-cutter, then a mechan­ical digger,” says 39-year-old Rémi Dieuzaide. Since becoming a simpli­fied joint-stock company (SAS) in 2022, Dieuzaide TP has really spread its wings – and today has 15 employees and nine diggers at its service, including a 30t machine. Special­ising in earth moving and clean-up oper­a­tions, the company works throughout the Grand Sud-Ouest region of France.

Although the director of the Gers-based company would never discount any project, including decon­t­a­m­i­nating pollu­tion, within this large area extending from Nîmes to Cognac, he has acquired a targeted niche. “We have patiently acquired exper­tise in archae­o­log­ical exca­va­tions, and we are going to try to develop our repu­ta­tion in this area,” explains Rémi, who is expecting to sign off on a substan­tial site on the edge of Toulouse for this coming September.

For infor­ma­tion on a pres­ti­gious archae­o­log­ical exca­va­tion site in which Dieuzaide TP was involved.

Fuel economy target

For its earth moving oper­a­tions, Dieuzaide TP has two John Deere trac­tors, which operate between 1,500 and 2,000 hours per year. Acquired from the Ets Dupuy’s Solo­miac facility, they are a 6R155 model and a 6R185 model. “These vehi­cles are very reli­able, and can manage very well on diffi­cult sites,” Rémi claims.

But like every good manager, he keeps a close eye on his costs, and on fuel consump­tion in partic­ular, as his equip­ment is required to travel substan­tial distances by road – bearing heavy loads. Before settling recently on a 6R185 model, the company was loaned a model from the supe­rior 7R range. “We came back to a mid-frame tractor from the 6R range: Easier to handle and with no unnec­es­sary kilo­me­tres on the road to help keep our fuel consump­tion down,” explains Rémi.

JDLink, the ulti­mate judge

“I am not surprised by Mr Dieuzaide’s choice with regard to fuel economy,” admits Paul de Lafor­cade, sales director at Ets Dupuy, a John Deere deal­er­ship with a market share of around 30% in the depart­ments of Landes, Haute-Garonne, Gers, Tarn and Tarn-et-Garonne. When his team is asked about fuel economy, Paul always brings out the JDLink argu­ment. This work data collec­tion system – which any John Deere customer can join – shows a tractor’s consump­tion under actual and compa­rable condi­tions.

Paul knows his ‘mid-frame’ product in the 6R range well: “It has a 6.8-litre engine with six cylin­ders, weighs 7.9t unladen, on a wheel­base of 2.77m.” But the figures aren’t every­thing. “At John Deere, we continue to stake our name on quality of service: The promise of fuel economy cannot be kept without fault­less trans­mis­sion settings, quality start-up, perfectly aligned tyres, etc.”