We have recently successfully completed a project for the North Atlantic Waste Syndicate (SMCNA) in Treffieux (44). Our mission was to assess the compliance of the no. 2 waste leachate pond before changing the use of this pond.


View of the pond

The Syndicat Mixte Center Nord Atlantique is a waste treatment organization that currently manages the “Brieulles” waste treatment facility (landfill) in Treffieux. The processing center consists of a sorting center for household packaging, a non-hazardous waste storage facility (landfill ISDND of class 2), and a waste disposal facility. The Syndicate is composed of 5 Communities of participating municipalities:

– The Community of Municipalities of the region of Nozay (CCRN)
– The Community of Municipalities of the region of Blain (CCRB)
– The Community of Municipalities of Erdre and Gesvres (CCEG)
– The Community of Communes Loire and Sillon (CCLS)
– The Community of Communes of the Pays de Pontchâteau-Saint Gildas des Bois (CCPSG)

Expertise of the geomembrane


Example of failure identified on a double track weld

An expert visit was carried out on 7 October 2016 to check the condition of the HDPE liner at the bottom and flanks of pond No. 2.

We carried out the inspection quickly after the drainage and cleaning of the pond (after completion of the Hygiene and Safety plan). The expertise of the HDPE liner consisted in:

  • Visual inspection of the sealed surface in order to note the visible irregularities (hollows, folds, embankments, punchings …);
  • Checking the weld line by applying pressure to penetrate it between the layers of geomembrane for lack of adhesion;
  • Vacuum test of triple points and certain welds (vacuum pump).


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View of the leachate pond during the inspection



Expertise identified various defects that were identified and reported to the owner (report with photos and summary table + marking on the geomembrane on site).

The SMCNA then proceeded, on the basis of this documented report, to the repairs by an outside company.  At the end of this mission, SMCNA indicated that:


The services were carried out in accordance with good practice, to our complete satisfaction and on time.

The carbon footprint was estimated at 102 kg CO 2 e (high value, considering the  uncertainties).

We have taken care to minimize these emissions throughout the project. For those that we could not avoid, they were offset  by the purchase of a carbon offset certificate (1 ton of  CO2e) through the installation of an effluent treatment plant with a methane recovery digester at Kamphaengphet in Thailand. This project is accredited Gold Standard under the Clean Development Mechanism (CDM) of the United Nations Famework Convention on Climate Change (UNFCCC).

This project is therefore Neutral Carbon