Greenwich Mohawk Brownfield Remediation -Full Scale Implementation

The City of Brantford is remediating a 21 hectare site less than one kilometre outside of Downtown Brantford to redevelop into a mix of future residential, park, institutional and commercial redevelopment. The Greenwich Mohawk site, which is a composite of three properties (22 Mohawk street, 66 Mohawk Street, and 347 Greenwich Street), is heavily contaminated with a high volume of petroleum hydrocarbons (PHCs) and volatile organic compounds (VOCs), and heavy some metals from a history of industrial manufacturing. The city is using a combination of in-situ and ex-situ remediation techniques on the site. In heavily contaminated areas, they are excavating and disposing of soils as required by the Ministry of Environment, while in other places they are treating the contaminated soil through a combination of engineered biopiles and air sparging. Biopiles is a remediation technique using mechanical aeration and the application of minerals, nutrients, and moisture to increase aerobic microbial activity to break down contaminants. Air sparging or soil vapour extraction involves injecting air below the water table and extracting vapours from above the water table, which promotes the volatilization of contaminant and the biodegradation of petroleum hydrocarbons. On 347 Greenwich Street property, approximately 20 to 25 percent of soil will be excavated and disposed offsite at a licensed landfill facility. This revised remediation plan will apply to the areas of 347 Greenwich Street property which remained to be treated after November 10, 2015. Whereas conventional remediation involves the excavation and removal of large volumes of contaminated soil to landfill sites, in-situ techniques reduce costs and the environmental impacts of transporting contaminated soil, as well as minimizing the volumes of clean fill required on site. The city is aiming to remediate the entire site by December 31, 2016 while minimizing disruption to the nearby residential neighbourhood and adjacent industries. Deliverables for the project include obtaining a record of site condition and completing a risk assessment for future site use. The Brantford planning department has consulted with residents and other project stakeholders through public meetings, open houses, workshops and advisory groups. They will monitor the air, dust, surface water and groundwater around the site to ensure the safety of the community, site workers and the natural environment during remediation. Consultants will also perform ongoing sampling of soil after the remediation is complete using GPS tracking devices for detailed quality control, as well as installing groundwater monitoring wells. The project is in line with strategic directives for remediation and redevelopment outlined in Brantford’s Official Community Plan and Community Improvement Plan, and is supported by tax incentives for the redevelopment of brownfield sites. The city expects the remediation to provide short-term jobs, as well as increasing property tax revenues and stimulating new economic investment in the Eagle Place neighbourhood. (Project description from original funding application)