287 Lisgar Street Redevelopment Risk Management Plan, Claridge Homes, Ottawa

Claridge Homes will complete a Risk Management Plan to support the addition of a vapour mitigation system at 287 Lisgar Street, a 0.091 ha residential development in the City of Ottawa. As part of this initiative, Claridge Homes will also complete a Human Health Risk Assessment, an Ecological Risk Assessment, a Record of Site Condition (RSC), and a ‘lessons learned’ report aiding in replicating this type of vapour mitigation system on other sites. A Phase II Environmental Assessment identified contaminant concentrations on site in the soil and groundwater. Immediately adjacent to the north of the site, a former dry cleaner was present. The groundwater flowing onto the site is contaminated with volatile organic compounds (VOCs) and petroleum hydrocarbons (PHCs) that are likely attributed to the former dry cleaner and heating oil tanks that were also north of the site. Claridge Homes is proposing to construct a residential condominium consisting of 108 residential units, with four levels of underground parking that will encompass the entire footprint of the site. The initiative includes managing the risk of exposure to vapours associated with historical contamination by installing a sub-slab vapour mitigation system in the underground parking garage. This will be accompanied by the removal of approximately 9000 metric tonnes of soil determined to be contaminated by VOCs and PHCs. Claridge Homes will collaborate with the Ministry of the Environment and Climate Change to ensure the plans and risk management measures are in compliance with the relevant regulations. The initiative will aid in development of a brownfield site as per the Brownfields Redevelopment Program of the City of Ottawa. The site qualifies to be a part of the Ottawa Brownfields Community Improvement Program because of its urban location (centretown) and proximity to the transit system. Furthermore, this initiative contributes to Ottawa’s Environmental Strategy, which indicates the social and economic value of redevelopment of brownfields, on top of the environmental benefits of infilling urban areas. (Project description from original funding application)