|Client:||Transamerica Life Insurance Company of Canada|
|Specific Role:||Deep off-site drilling|
XCG was retained to conduct a Phase Two Environmental Site Assessment (ESA) to delineate and quantify subsurface soil and groundwater impacts on a 30 acre property, occupied by a large plant that had manufactured steel office furniture and other steel products since the early 1930s. This property had been acquired by Transamerica as a result of a foreclosure, and required decommissioning and demolition prior to being sold and redeveloped.
The subsurface investigations on this site detected elevated concentrations of trichloroethylene (TCE) and other related compounds in the groundwater within a confined aquifer beneath one area of the site. The confined aquifer is used as a source of drinking water by the municipality, approximately 800 metres from the subject site. The confined drinking water aquifer consists of a layer of primarily sand, which is overlain by an aquitard of silty clay till about five to fifteen metres thick, which in turn is overlain by a surficial aquifer unit of granular soils about five to ten metres thick. The TCE concentrations found in groundwater samples from the confined aquifer ranged from about 3,500 µg/L to 15,000 µg/L.
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XCG conducted off-site deep drilling to delineate the horizontal and vertical extent of the TCE plume. Twenty-six deep monitoring wells were installed, with screens placed in the confined drinking water aquifer at depths ranging from 30 to 50 metres below the ground surface. The monitoring wells included single monitoring wells, as well as clusters of two or three wells screened at different depths within the deep aquifer.
Following the delineation of the plume, a pump-and-treat system using a UV oxidation system as the groundwater treatment process was installed. Subsequently, the property was redeveloped as a senior’s retirement village (Luther Village) under the management of MacNaughton, Hermsen, Britton, Clarkson (MHBC) Planning Ltd.