Remediating highly sought-after brownfields

(France)

Remediating highly sought-after brownfields

Constrained by increasing pressure on urban land, local authorities, manufacturers and developers are taking a close interest in many polluted sites on the outskirts of cities. However, in order to be able to launch any project to regenerate these brownfield sites, the land must first be decontaminated. Through its subsidiaries GRS Valtech and EOD-EX, Veolia’s entity, SARPI, boasts wide-ranging know-how in this domain. This expertise also allows it to work within very restricted time frames.

Issue

Responding to urban densification and preventing urban sprawl

Goal

Free up land in cities by rehabilitating former brownfields and making them safe

Veolia's response

Treating extreme pollution, and comprehending, managing and neutralizing the risk of explosion

France counts 400,000 abandoned polluted sites. In other words, hundreds of hectares to be treated and restored before they can be used for hosting public facilities, setting up light industry, building housing, or even developing an urban farming business. This land resource offers a solution to the problem of urban sprawl. However, soil decontamination is an indispensable prerequisite to allow future users to work and live in a healthy environment.


Explosives decontamination of the former 217 air base in Brétigny-sur-Orge.

Explosives decontamination of the former 217 air base in Brétigny-sur-Orge.


In Saint-Ouen (France),

In Saint-Ouen (France),

GRS Valtech cleaned up ground set to accommodate the maintenance and storage site for carriages from the Paris metro’s line 14.

Hunting down and handling explosives, wherever they are

EOD-EX was created in 2006 by SARPI, Veolia’s “hazardous waste management” branch, and the SNPE group (leader in the design and manufacture of explosive items and substances). In 2011, the company became a fully-owned subsidiary of SARPI, enriching Veolia’s offering in terms of global explosive risk management. EOD-EX is involved in four areas of activity: geophysical diagnosis, dismantling for the pyrotechnics industry, landmine clearance, and underwater demining. The company has 45 highly qualified experts to carry out these missions. These include former army bomb disposal experts and applied geophysics engineers. Requests primarily come from the French Ministry of Defense and manufacturers looking to sell land. EOD-EX uses several sources to perform a geophysical diagnosis. For instance, experts study warplane flight plans and photos taken before and after the bombings. For detection on site, techniques are constantly evolving, with the positioning of materials allowing more precise distinction of the magnetic anomalies detected. The use of drones has led to a significant improvement in mapping operations. Once the elements have been detected, they are excavated and dealt with in situ or in specific centers. Construction workers can then work under optimal safety conditions.

Managing complex and sensitive pollution

“Sarp Industries, Veolia’s entity dedicated to hazardous waste treatment and recovery in Europe, is represented on this market through its subsidiaries GRS Valtech and EOD-EX,” explains Cédric L’Elchat, its CEO. “GRS Valtech, created in 1990, is involved in the decontamination of soils and liquid and gaseous effluents,” he continues, “while EOD-EX is a major player in the remediation of explosive-contaminated1 soil.”

An integrated approach, paired with cutting-edge expertise, allows both companies to respond rapidly and prove their efficacy and adaptability on projects that often have many constraints. For example, in Saint-Ouen (France), GRS Valtech cleaned up ground set to accommodate the maintenance and storage site for carriages from the Paris metro’s line 14.

“We began in October 2014 and the work should be finished by the end of 2019,” explains Pascal Escoubas, CEO of GRS Valtech and EOD-EX. “Within this framework in keeping with an approved process, we excavated and then treated over 350,000 metric tons of earth and sludge, maintaining an average evacuation rate of 1,500 to 2,400 metric tons per day.”

Over 50,000 metric tons of material was transported by river to limit the number of trucks in the northern Paris suburbs, where the road traffic is already very dense.

“Our schedule frequently changed, because we had to adapt to the vagaries of the progress of the earthworks and civil engineering. Given this constraint and the volumes in play, we prepared the evacuation of the earth and sludge at a very early stage. So the volumes were divided into different batches according to their quality, which allowed us to optimize management costs and draw up contracts with different channels,” continues Pascal Escoubas.

As well as evacuating earth and sludge, GRS Valtech also pumped and treated over 730,000 m3 of phreatic groundwater on site.

Demining explosive sites

The subsidiary EOD-EX, which is active in France and Europe, is most often called on to clean up explosives-contaminated land, primarily by the French Ministry of Defense and manufacturers. The aim is to guarantee optimal safety for construction companies during their work. In the Paris region, EOD-EX won the diagnosis and explosives decontamination contract for the former 217 air base in Brétigny-sur-Orge in 2017. The Second World War has left its mark there. During the Occupation, the base was heavily bombarded by the Allies. After sounding the 300 hectares looking for grenades or bombs dating from this period, EOD-EX’s teams carried out the geophysical diagnosis and decontamination of 120 hectares to a depth of six meters. The specialists work using radars. Once they obtain an echo, they dig to find out the nature of the “object” detected. Two 50-kg bombs — still intact — were found, one buried at a depth of 70 cm, the other 2.5 m down. They were covered with 200 metric tons of sand and encircled by a trench to limit the propagation effect. Then charges were put in place to explode them. In total, this site uncovered over 15,000 “targets,” forty or so of which were still active.
 

Chiffres clés

€750 M, estimation of the soil decontamination market in France
Almost 200 projects carried out by GRS Valtech in 2018, around 500,000 metric tons of earth and 2 million m3 of liquid effluent treated
45 million metric tons of earth to be excavated for the Grand Paris Express projects,
10% of which are thought to be polluted
Over 300 projects conducted by EOD-EX since its creation (2006)
Over 80 metric tons of munitions extracted and/or treated since 2010 by EOD-EX

 

More:

World Soil Day: Veolia takes action on availability and quality
Soil remediation: a second life


1. Related to explosive devices, such as unexploded bombs and munitions cases (which may contain toxic compounds such as arsenic and lead).

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