> Air Quality - Environmental Impact Assessment Report | Metrolinx Engage

Warning message

Submissions are closed.

Air Quality - Environmental Impact Assessment Report

← Return to Draft Environmental Impact Assessment Report

Key Findings

Typical of highly urbanized environments like the City of Toronto, there are existing Ministry of Environment, Conservation and Parks Air Quality Guideline exceedances of vehicle exhaust combustion criteria such as benzene and benzo(a)pyrene. Background concentrations of these contaminants are also generated by regional industrial operations.

  • Vehicular, rail and industrial emissions were identified as sources of emissions impacting overall air quality in the Study Area.
  • The operation of the Project would support the overall provincial objective in shifting towards a more sustainable mode of transportation, with an estimated reduction of 266,000 kilometres travelled by private vehicles per day.
  • The Ontario Line supports provinical objectives to provide more sustainable modes of transportation and reduce greenhouse gas emissions by up to 14,000 tonnes per year. There will also be up to 7.2 million fewer litres of fuel consumed each year.
  • 145 existing representative sensitive receptors*, and 71 potential future sensitive receptors have been identified in the Study Area.
  • 90 existing critical receptors**, and six potential future critical receptors have been identified in the Study Area.
  • Receptors are representative points where projected air quality impacts are measured.
  • There is potential for temporary increases in air quality emissions associated with construction vehicles. Potential construction air quality impacts will be managed by implementing a suite of mitigation measures, such as using low emission construction equipment and dust suppressants.
  • Ambient air monitoring will be conducted to confirm the effectiveness of the mitigation measures and allow for adaptive management, as required.

*A sensitive receptor is a building in which a person resides on a permanent or semi-permanent basis, such as a house or an apartment.
**A critical receptor is a location where sensitive populations reside or spend a significant amount of time daily, such as schools, retirement homes, hospitals, or day cares.

Potential Effects & Mitigation Measures

Potential Effects:

Construction

  • Increase in air pollution and odour because of construction vehicle emissions and increased traffic due to construction activities.
  • Increase in dust, silica and airborne particulate matter resulting from earthworks, material handling and transfer, demolition, and construction activities.
  • Construction activities could expose contaminated soils/ materials and/or result in the spreading of contaminated materials.
  • Greenhouse gas emissions are expected to increase temporarily due to construction activities, but a net overall decrease in Greenhouse gas emissions will occur as a result of the operation of the Project.

Operations

  • There is expected to be a net overall decrease of 14,000 tonnes of greenhouse gas emissions per year.
  • Operation of the maintenance and storage facility and maintenance staff may cause minor air quality impacts from work vehicle fuel combustion and maintenance activities.

Example of trucks spraying water as part of dust control mitigation

Example of trucks spraying water as part of dust control mitigation.
Source: Metrolinx 2020

Mitigation Measures:

Construction

  • Dust monitors will be used in some areas to monitor allowable dust levels and when mitigation measures will be required.
  • A detailed Construction Air Quality Management Plan will be developed and implemented to manage air quality throughout construction.
  • Dust suppressants such as water sprayers will be used, as required.
  • Low emission construction equipment will be used, wherever possible.
  • A Communications Protocol will be developed to encourage timely resolution of complaints.
  • Crews will reduce the amount of machines operating in one area at any given point where possible.
  • Visual and olfactory inspections will be conducted during excavation or for incoming loads to screen for odour, visible staining or debris per the Ministry of Environment, Conservation and Parks Management of Excess Soils, A Guide for Best Management Practices (2019).

Operations

  • A detailed Operations Air Quality Management Plan will be developed and implemented.
  • Emissions will be assessed and modelled following Ministry of Environment, Conservation and Parks guidance and will comply with applicable Ontario Regulation 419/05 standards.
  • To reduce emissions intensity at the maintenance and storage facility, select equipment with engines and propulsion systems that meet higher emission standards (i.e., Tier 4 rather than a lower tier) will be used.

← Return to Draft Environmental Impact Assessment Report

Submissions are closed.