Changes

Design and operation and maintenance program assumptions used to generate cost estimates are based on tool default values and the following STEP recommendations:

Design and operation and maintenance program assumptions used to generate cost estimates are based on tool default values and the following STEP recommendations:

* Native soil infiltration rates for Full, and Partial Infiltration Design scenarios were assumed to be 20 mm/h and 10 mm/h respectively, and a safety factor of 2.5 was applied to calculate the design infiltration rate.  

* Native soil infiltration rates for Full Infiltration Design scenarios were assumed to be 20 mm/h, and a safety factor of 2.5 was applied to calculate the design infiltration rate.  

* Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and removal of sediment from pretreatment structures annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ chamber system water level monitoring during natural storm events.

* Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and removal of sediment from pretreatment structures annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ chamber system water level monitoring during natural storm events.

* Infiltration chamber system length of 5 metres and composed of 22 chambers in total.

* Infiltration chamber system length of 5 metres and composed of 22 chambers in total.

===Notes===

===Notes===

* Designs include [[pretreatment]] through hydrodynamic separator ([[Oil and Grit Separator| i.e., oil and grit separator]]) and isolated chamber row.

* Design include [[pretreatment]] through hydrodynamic separator ([[Oil and Grit Separator| i.e., oil and grit separator]]) and isolated chamber row.

* The tool calculates costs for new (greenfield) development contexts and includes costs for contractor overhead and profit, material, delivery, labour, equipment (rental, operating and operator costs), hauling and disposal.  

* The tool calculates costs for new (greenfield) development contexts and includes costs for contractor overhead and profit, material, delivery, labour, equipment (rental, operating and operator costs), hauling and disposal.  

** Land value and equipment mobilization and demobilization costs are not included, assuming BMP construction is part of overall development site construction.

** Land value and equipment mobilization and demobilization costs are not included, assuming BMP construction is part of overall development site construction.

==Construction Costs==

==Construction Costs==

[[File:ConstructionTable InfilChamb Full Infil.PNG|thumb|left|610px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Full Infiltration Design, 25 mm Retention''']]

[[File:ConstructionTable InfilChamb Full Infil 2023.PNG|thumb|center|900px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Full Infiltration Design, 25 mm Retention''']]<br>

<small>'''Note:''' Click on image to enlarge to view associated construction cost estimates.</small><br>

 

 

<small>'''Note:''' Click on each image to enlarge to view associated construction cost estimates.</small><br>

 

 

As can be seen, regardless of design configuration, Material & Installation expenses represent the largest portion of total construction costs (75%).

As can be seen, regardless of design configuration, Material & Installation expenses represent the largest portion of total construction costs (75%).

==Life Cycle Costs==

==Life Cycle Costs==

Below are capital and life cycle cost estimates for the two [[Infiltration chambers|infiltration chamber]] design scenarios over 25- and 50-year time periods. The estimates of maintenance and rehabilitation (life cycle) costs represent net present values. Operation and maintenance costs are predicted to represent 37% of total life cycle costs over the 25-year evaluation period, and increase to 49% of total life cycle costs over the 50-year period, due to cost associated with removal of sediment from the isolated chamber row pretreatment devices every 8 years.

Below are capital and life cycle cost estimates for the [[Infiltration chambers|infiltration chamber]] design scenario over 25- and 50-year time periods. The estimate of maintenance and rehabilitation (life cycle) cost represents net present values. Operation and maintenance costs are predicted to represent 37% of total life cycle costs over the 25-year evaluation period, and increase to 49% of total life cycle costs over the 50-year period, due to cost associated with removal of sediment from the isolated chamber row pretreatment devices every 8 years.

 

===25-Year life cycle cost break down===

===25-Year life cycle cost break down===

[[File:25yr LCCT InfilChamb Full Infil.PNG|thumb|left|615px|'''Infiltration Trench: Full Infiltration''']]

[[File:25yr LCCT InfilChamb Full Infil 2023.PNG|thumb|center|900px|'''Infiltration Trench: Full Infiltration''']]<br>

<small>'''Note:''' Click on image to enlarge to view associated life cycle cost estimate.</small><br>

 

</br>

 

<small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br>

===50-Year life cycle cost break down===

===50-Year life cycle cost break down===

[[File:50yr LCCT InfilChamb Full Infil.PNG|thumb|left|615px|'''Infiltration Chamber: Full Infiltration''']]

[[File:50yr LCCT InfilChamb Full Infil 2023.PNG|thumb|center|900px|'''Infiltration Chamber: Full Infiltration''']]<br>

 

 

<small>'''Note:''' Click on each image to enlarge to view associated life cycle cost estimate.</small><br>

<small>'''Note:''' Click on image to enlarge to view associated life cycle cost estimate.</small><br>

==Cost Summary Tables==

==Cost Summary Tables==

Total life cycle cost estimates for the two [[Infiltration chambers|infiltration chamber]] configurations are the same with the total being ($120,218.83).<br>

Total life cycle cost estimate over the 50 year evaluation period for [[Infiltration chambers|infiltration chamber system]] on highly permeable native soil design scenario is $123,670.89.<br>

===Full Infiltration===

===Full Infiltration===

[[File:East Gwillimbury.png|800px|thumb|Example of "crate style" [[Infiltration chambers]] being installed in East Gwillimbury. Photo credit: [https://www.makeway.ca/products/stormwater-management-systems/ Make-Way Environmental Technologies Inc.]]

[[File:East Gwillimbury.png|400px|thumb|Example of "crate style" [[Infiltration chambers]] being installed in East Gwillimbury. Photo credit: [https://www.makeway.ca/products/stormwater-management-systems/ Make-Way Environmental Technologies Inc.]]

[[File:Design Table InfilChamb Full Infil.PNG|700px]]<br>

[[File:Design Table InfilChamb Full Infil 2023.PNG|830px]]<br>

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==References==

==References==