The Sabiston Landfill Site has been used by residents for over 38 years without any apparent issues. Why does the City of Markham feel there are now public health and safety issues? The latest results of the environmental monitoring indicate the level of contaminates within the site exceed the MOE Regulatory Requirements (e.g. both dissolved Arsenic and Trichloroethane, or TCE, exceed the requirements).
Additional data must be collected to properly define the extent of the contamination so that risks/impacts to various receivers (animal, human, environment, etc.) external to the site can be properly assessed using applicable MOE guidelines, Acts, Regulations, etc.
The City of Markham is using a consultant (AMEC Environment and Infrastructure) with expertise to undertake testing and analysis of the landfill area. What credentials and experience do they have? AMEC has been actively involved in waste disposal and management for over 50 years, and possesses significant experience in all aspects of landfill engineering including feasibility studies, design, construction, operation, monitoring, closure and post-closure.
AMEC has completed engineering studies for landfills for several key organizations including the Ministry of Transportation, the Ministry of the Environment, City of Hamilton and City of Ottawa.
What are the environmental impacts of installation of groundwater monitoring wells? The City is sensitive to the natural environment and Species at Risk wildlife habitat that is present on the former Sabiston Landfill Site.
Markham staff hired Dillon Consulting, a recognized leader in the environmental monitoring industry, to prepare a full Environmental Monitoring Management Plan (EMMP) to minimize impacts to the surrounding natural environment during the well installation and ensure the site is fully restored to original condition upon completion of the work.
Dillon Consulting has indicated that if the work is carried out during the winter months, the potential of encountering or disturbing wildlife on the site is low.
The Ministry of Natural Resources has determined the well installations will not adversely affect Species at Risk such as the Eastern Meadowlark, or their habitat, as long as certain conditions are implemented.
If wildlife is encountered, the City will take appropriate actions, as recommended in Dillon’s report.
What role do the Ministry of the Environment (MOE) and the Toronto and Region Conservation Authority (TRCA) play in the requirement for testing and environmental controls? In August 2013, Markham staff received approvals and permits from the TRCA and the Ministry of Natural Resources (MNR) to install the additional monitoring wells subject to work being completed by April 1, 2014.
Why is the City of Markham locating more groundwater monitoring wells? Installation of additional monitoring wells is a typical process in brownfield site (land previously used for industrial or commercial purposes) investigation. The process continues until the boundaries of the contamination plume are identified.
Proposed wells (11 wells at 8 locations) were strategically located to assess groundwater conditions down-gradient of the Site and in the deeper aquifer.
The full extent of the contamination is not currently defined and the extra wells are required to fully understand the impact distribution of the contamination at the Site (the extent of the contamination plume).
The City needs to determine whether leachate impacts are migrating deeper into the aquifer and / or farther down-gradient and off Site.
The City needs to ensure that the landfill operates in compliance with the applicable regulatory requirements.
How long will it take to install the new groundwater wells? The wells will be installed over a two to three week period beginning in late February/early March.
What will the installed groundwater monitoring wells look like? How big are they? Each monitoring well is 10 centimetres by 10 centimetres at the base and varies in height from 0.7 metre to 1 metre.