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SÉMECS biomethanization plant

The Société d’économie mixte de l’est de la couronne sud (SÉMECS) has mandated gbi to prepare, issue and ensure follow-up with the Ministry of the Environment and the Fight against Climate Change (MELCC) of the processing component of waters of its request for ministerial authorization for the purposes of research and experimentation in pretreatment of residual organic materials.

Environment, Industrial, Water treatment
Odors, Waste Management and Technical Landfills, Waste water

About the SÉMECS

Founded by the MRCs of Vallée-du-Richelieu, Marguerite-D'Youville and Rouville as well as by Biogaz EG, it serves the territories of the three MRCs, including 27 municipalities, for a population of approximately 700,000 people in addition to a wide range of institutions, businesses and industries.

The mission of SÉMECS is to process organic materials in order to recover renewable energy, reduce the quantities sent to landfill and reduce greenhouse gases.


The project included several stakeholders and different components, including the authorization request and follow-up with the MELCC, integrating the understanding of a new technology. The characterization and modeling of atmospheric dispersion were an integral part of this mandate.

Special features

Currently, nearly 50,000 tonnes of organic matter are processed in an eco-responsible way, into biogas and digestate. Digestate is an organic fertilizer intended for neighboring SÉMECS agricultural land to increase the level of organic matter in the soil. This year, more than 10,000 tonnes of digestate were returned to the earth.

Also, 4 million cubic meters of biogas are recovered and used at Greenfield for the production of ethanol or injected into the Énergir network. From December 2022, the capacity to process organic materials will prevent 120,000 tonnes from being landfilled per year.