Former Dry Dock and Shipyard, Kingston, Ontario

XCG completed an updated Phase One Environmental Site Assessment of this former federally-owned waterfront property in Kingston. The property had been used in the past for a variety of industrial activities including a dry dock, a shipyard, a military reserve with an artillery battery, workshops, a marine railway yard, a foundry, and a sawmill.

The Phase Two ESA identified petroleum hydrocarbons (PHCs), volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), and metals and inorganics in both soil and groundwater. Exceedances of PAHs and metals were also identified in sediment samples, collected from offshore upstream and downstream locations on Lake Ontario and from directly adjacent to the subject site. The property was found to have a layer of poor quality fill material over most of its area, consisting of discontinuous layers of silt, sand, silty sand, cinder, gravel, cobbles, boulders, limestone shale, brick, coal, clay, silty sandy clay, silty peaty clay, and sediment.

A soil vapour survey was also completed   to provide information needed for undertaking a Risk Assessment. A comprehensive Tier 3 Risk Assessment (RA) and Risk Management Plan (RMP) were completed to address the contamination on-site. The proposed risk management measures include hard cap/fill cap, an active soil vapour mitigation system for future buildings and/or construction of buildings with a storage garage on the lower level, modified subsurface worker protection plan, and a shoreline protection system. This project is ongoing and the completed RA and RMP are under review.

One challenge at this site was the need to use a barge to get drilling equipment onto a limited-access area. A small hand-held drilling tool was not suitable due to the depth of drilling required.

Implementation of a shoreline protection system is also a particular challenge at this site due to the presence of badly deteriorated wharf retaining walls around much of the perimeter of the property. XCG is working with a team of engineers to develop a retaining wall design that will provide the environmental protection required based on the RA findings as well as the necessary structural stability to allow for future construction of a high-rise  building.