Changes

=Erosion risk assessments (ERA)=

=Erosion risk assessments (ERA)=

To manage the potential negative impacts of construction activities in the absence of effective ESC measures, Erosion Risk Assessments (ERAs) are conducted to guide the selection and placement of appropriate ESC practices on site. ERAs are recommended when:  

To manage the potential negative impacts of construction activities in the absence of effective ESC measures, Erosion Risk Assessments (ERAs) are conducted to guide the selection and placement of appropriate ESC practices on site. ERAs are recommended when:  

*the extent of land disturbance is greater than 10 ha and duration is longer than 30 days, or

{{textbox|*the extent of land disturbance is greater than 10 ha and duration is longer than 30 days, or

*construction activities are planned in or near natural water features, or

*construction activities are planned in or near natural water features, or

*the site drains to [https://www.ontario.ca/laws/regulation/080230 species at risk (SAR)] habitat

*the site drains to [https://www.ontario.ca/laws/regulation/080230 species at risk (SAR)] habitat}}

The hybrid qualitative ERA approach is recommended in the above situations with the exception of instances where local regulatory agencies require a different approach. The hybrid qualitative ERA approach estimates erosion risk by dividing a site into areas based on soil, slope, and ground cover, then rating each area as low, moderate, or high erosion risk (link erosion potential subsection) to help choose the right erosion control practices for each stage of construction.

The hybrid qualitative ERA approach is recommended in the above situations with the exception of instances where local regulatory agencies require a different approach. The hybrid qualitative ERA approach estimates erosion risk by dividing a site into areas based on soil, slope, and ground cover, then rating each area as low, moderate, or high erosion risk (link erosion potential subsection) to help choose the right erosion control practices for each stage of construction.

=ESC plan design=

=ESC plan design=

An ESC plan should be created based on a given site’s ERA, with more controls used in the higher risk areas. An ESC plan should be designed for each stage of construction:  

An ESC plan should be created based on a given site’s ERA, with more controls used in the higher risk areas. An ESC plan should be designed for each stage of construction:  

#Topsoil stripping, and re-stabilization

{{textbox|#Topsoil stripping, and re-stabilization

#Servicing  

#Servicing  

#Building construction  

#Building construction  

#Final stabilization/rehabilitation and ESC decommissioning

#Final stabilization/rehabilitation and ESC decommissioning}}

==Types of ESC==

==Types of ESC==

*Erosion controls prevent exposed soils from being entrained by water or wind. Practices that prevent erosion are the most effective BMPs because they address sediment at its source.  

{{textbox|*Erosion controls prevent exposed soils from being entrained by water or wind. Practices that prevent erosion are the most effective BMPs because they address sediment at its source.  

*Sediment controls address the removal of sediment suspended in stormwater (reactive) through settling (link sedimentation page) and filtration (link filtration page).

*Sediment controls address the removal of sediment suspended in stormwater (reactive) through settling (link sedimentation page) and filtration (link filtration page).}}

The most effective way to apply ESC is to use a multi-barrier approach, which involves the installation of both types of controls in series, to create a resilient system capable of protecting the natural environment from sediment impacts. In a multi-barrier system there is redundancy so that if one control fails, there are still others in place to safeguard downstream features. Selecting the appropriate BMPs for each project stage requires an understanding of BMP function, intended use, expected performance, and maintenance required.

The most effective way to apply ESC is to use a multi-barrier approach, which involves the installation of both types of controls in series, to create a resilient system capable of protecting the natural environment from sediment impacts. In a multi-barrier system there is redundancy so that if one control fails, there are still others in place to safeguard downstream features. Selecting the appropriate BMPs for each project stage requires an understanding of BMP function, intended use, expected performance, and maintenance required.