Essai pilote pour la remise en état du terrain situé a Ste-Thérèse

The City of Sainte-Thérèse is testing a soil vapour extraction technique combined with thermal enhancement to remediate a city-owned property contaminated by toluene, an aromatic hydrocarbon that is widely used as an industrial feedstock and as a solvent. The 9,500 m2 property is located in a residential neighbourhood. The contamination was discovered in 2004, during Phase I and Phase II Environmental Site Assessments (ESA) conducted for a potential sale of the property. The source of contamination is suspected to be an underground toluene reservoir located on-site to the west of the property. The City has examined potential remediation technologies and redevelopment options. Due to the type and the depth of contamination, thermal enhanced soil vapour extraction technique was identified as the preferred option, based on the high probability of meeting site remediation criteria, minimum technological risks and the low risk of potential hazards to the community. The field test will apply this technique where the contamination is known, and a supplemental Phase II ESA will be conducted to delineate the contaminated area on the property located west of site. If the field test is successful and the technology is applied to the entire site, estimates predict a 98 percent (1,398.4 kg) reduction in toluene concentration. Remediation of the property will also eliminate the risk of the contaminant migrating to the groundwater and to other properties.