An Environmental Assessment (EA) study is underway to identify problems and assess sanitary servicing needs of the Black Creek Sanitary Drainage Area and capacity of the Black Creek Sanitary Trunk Sewer, and develop a plan to:

  • ensure the Black Creek Sanitary Sewer Drainage Area has capacity to service future projected growth
  • better manage sanitary and combined sewer flows in the drainage area during rainfall events
  • reduce combined sewer overflows within the study area to Black Creek watercourse
  • reduce stormwater entering the Black Creek Sanitary Trunk Sewer (STS)
Area Map of the Black Creek Drainage Improvement Study

Built around 1960, the Black Creek STS is a 15 km sanitary trunk sewer that services the 5,700 hectare Black Creek Sanitary Drainage Area.  The Black Creek STS is a tributary to the Humber STS and ultimately conveys sewage to the Humber Wastewater Treatment Plant.

The Black Creek STS has experienced capacity issues during some rainfalls, which have caused flooding due to the surcharging of the trunk sewer.  Over the next few decades, a significant population increase is expected to occur within the Black Creek sanitary drainage area, which will result in an increase in capacity constraints on the trunk sewer.  In addition, during some storms, combined sewer overflow discharges to Black Creek occur from three combined trunk sewers that flow into the Black Creek STS.

Three sets of Public Information Centres (PICs) occurred for for this Class EA project. The first set of PICs took place in the spring of 2016. The second and third sets of PICs took place in fall and winter of 2016. Notification of the PICs were advertised in the local community newspaper and notices were mailed to residents within the study area.

Notice of Public Information Centre # 1

Study overview

The City of Toronto has initiated a Municipal Class Environmental Assessment (EA) study to address problems and opportunities with the Black Creek Sanitary Trunk Sewer (STS) within the Black Creek Sanitary Drainage Area (see study area map). The purpose of the Class EA study is to assess capacity issues of the Black Creek STS and to address the adverse impacts of combined sewer overflows to Black Creek within the study area. The study will recommend solutions to achieve the following objectives:

  • accommodate sanitary flows for projected future growth in the sanitary drainage area
  • reduce surcharge levels of the Black Creek STS
  • reduce combined sewer overflow discharges to Black Creek
  • reduce Inflow and Infiltration into the Black Creek STS

The process

The study is being planned as a Schedule “C” project under the Municipal Class Environmental Assessment document. The Class EA process provides members of the public and interested parties with opportunities to provide input at key stages of the study. The studies will define the problem and the causes of the problem, consider and evaluate alternative solutions, assess impacts of the preferred solutions, and identify measures to lessen any adverse impacts.

What is a Class Environmental Assessment?

Ontario’s Environmental Assessment (EA) program promotes good environmental planning by determining and managing the potential effects of a project prior to implementation.

The EA program ensures that public concerns are heard. EA balances economic, social, cultural and natural environmental needs so that projects benefit Ontario.

This study is being carried out according to the Municipal Class Environmental Assessment process. This is an approved approach to satisfying requirements of the Environmental Assessment Act specifically tailored to municipal infrastructure. The process includes identifying the problem or opportunity to be addressed, developing and evaluating a range of alternative solutions, providing opportunities for public input and identifying a preferred solution.