Pinchin LeBlanc Environmental Ltd. - Representative Projects

Environmental Remediation and Risk Assessment

Environmental Remediation and Risk Assessment PLEL conducted a Phase II Environmental Site Assessment (ESA) at a property in Halifax, Nova Scotia. The Phase I ESA (also conducted by PLEL) identified gaps in information regarding petroleum storage on the site. An intrusive soil and groundwater investigation was recommended to gather further information on the environmental condition of the site, establish whether there are liabilities associated with its ownership or control, and assess the environmental information as compared to current environmental standards.

Representative soil and groundwater samples were obtained from boreholes, test pits and monitor wells. Petroleum concentrations in soil exceeded applicable Tier I Risk Based Screening Levels (RBSLs). Therefore, a Phase III ESA was conducted to delineate the area of impact to allow Tier II RBCA modelling of the site. The Tier II modelling would provide Site Specific Target Levels (SSTLs) for remedial guidelines.

Environmental Remediation and Risk Assessment To determine the extent of impacted soil under the building, a test pit was excavated in an earthen floor crawl space beneath the building. During the excavation, copper lines were noted entering the crawl space through the north wall of the building. The lines were found to be connected to a 4546-litre (1000-gallon) UST located near the north property boundary. The UST was removed and trucked to an approved disposal facility. Approximately 25 tonnes of impacted soil were recovered from the tank excavation. Clearance soil samples were obtained from the boundaries of the tank excavation. Following the removal of the UST, Phase III delineation was completed.

Environmental Remediation and Risk Assessment Based on the delineation described above, the Atlantic RBCA (Risk Based Corrective Action) for Petroleum Impacted Sites in Atlantic Canada (Version 2.0, October, 2003) process was applied to site conditions. Tier II SSTLs were calculated for the soil and groundwater. Soil and groundwater sample concentrations were within the SSTLs calculated through the Tier II RBCA model. A Site Management Plan was prepared for the property to reduce the risk of exposure to the identified petroleum impacts. This included pouring a concrete floor in the earthen basement so that the site would conform with the applicable regulatory requirements for implementation of the Atlantic RBCA process.