Environmental Fact Sheets

The decontamination process used by Décontam consists of a bioaugmentation treatment which relies on a bacterial consortium with the addition of nutriments, including phosphorus and nitrogen. The substance is injected with a minimal amount of dechlorified water. The technology applies to soils contaminated by petroleum, diesel and light petroleum hydrocarbons.

Basically the process is as follows. During the initial stage of biotreatment, the various chains of hydrocarbons are subdivided thereby increasing the number of available hydrocarbon molecules. Following this increase in the concentration in the parameters of hydrocarbon, the biological process, with the micro-organisms, the enzymes and the extra-cellular enzymes, continues to reduce the organic components in simpler chemical elements thus allowing the micro-organisms to use these elements as a source of energy and carbon to further convert them to carbon dioxide and water.

Contrary to decontamination by bioventilation, the process does not require air extraction through the soil. The bioaugmentation is carried out without the presence (anaerobic) as well as with the presence (aerobic) of oxygen.

The treatment takes place inside a building with large storage capacity and with equipment ensuring the control and treatment of contaminant emissions generated during the decontamination process.

Regarding the generic criteria of the ministère du Développement durable, de l’Environnement et des Parcs, this treatment process allows soils to attain the level of A-B or less thus allowing its reuse in residential settings.

The platforms inside the building allow for the treatment of 60,000 metric tons of contaminated soils. The duration of the treatment varies based on the types and concentrations of the contaminants as well as the gradation of the soils.

The process does not produce leachate water, given that it does not require a significant amount of water, that no mud is accepted and that the soils are protected from the rain given they are indoor. For the control of the quality of the air, the purification systems have two beds which serve as filters for dust and the absorption of granular activated carbon. As for monitoring the emissions, this consists of measuring the presence of volatile organic composites, with the use of photoionizer, on the carbon filtration pipes as well as around the facility. It is also necessary on a regular basis to analyse samples of the air taken at the exit of the purification systems.

The efficiency of the treatment by bioaugmentaion is limited by the permeability of the soils, the content of silt and clay not to exceed a certain level.

The soils to be treated can not contain toxic substances susceptible to prevent the development of the bacterias.

Moreover, the process does not allow for the elimination of inorganic contaminants such as metals.

The decontamination process takes place inside a building located in a commercial and industrial sector on the south west end of the city of Montreal, close to the Turcot exchange next to the Lachine canal. The treatment centre consist of three sections ,each having its own access points so that they may be used individually. The collection of water resulting from leaching the soil and washing of the equipment is carried out through a collection well, and as for the atmospheric emissions, the building is equipped with fixed and portable active carbon filtration units.

Although the soils accepted at the center have been previously characterized, on a regular basis, samples are randomly taken to verify its concentration. Soils contaminated with petroleum hydrocarbons are piled in a specific location based on the type and concentration of the main contaminants. After treatment, the soils are disposed of in accordance to the “Table for the management of contaminated excavated soils” (“Grille de gestion des sols contaminés excavés”) published by the ministère du Développement durable, de l’Environnement et des Parcs, found in Annex 1 of the guidelines for the treatment of soils by biodegradation, bioventilation and volatilization.

Waste water must be analysed before it is discharged in the municipal sewer, while the quality of the air, samples are taken and analyzed on a regular basis.

The prices established for the treatment are very competitive and vary in accordance to the degree of contamination , the type of soil, the duration of the treatment and the volume to be treated. In addition to the treatment, the prices include the strorage, the environmental follow-up and the subsequent disposal of the soils.

Décontam takes full responsibility of the soils upon their arrival at the treatment centre.

Important investments were required to obtain exclusive usage of the bioaugmentation treatment process and to adapt the installations of a previous plant to the conditions required to undertake the biotreatment of contaminated soils. These investments come entirely from the private sector.

The principal clients of this centre are developers, general contractors, consulting engineering firms and municipalities.

Décontam offers complete management of soils let it be for restoration of sites, secured landfill, excavation, transportation, biotreatment or soils valorization.