Changes

==Overview==

==Overview==

[[Permeable pavement|Porous Asphalt]] is an alternative to traditional impervious pavements that allow stormwater to drain through them and into a storage reservoir below. Porous asphalt's performance and integrity is similar to that of other standard asphalt pavements. Porous asphalt contains air pockets, which are created during the development process of the paver due to the inclusion of less fines and [[sand]] content in comparison to traditional asphalt. The "air pockets" or greater void spaces are what allow stormwater to infiltrate through the surface level to the underlying stone [[Reservoir aggregate|reservoir aggregate layers]]<ref>City of Toronto. 2017. Toronto Green Streets Technical Guidelines. Version 1.0. August, 2017. https://www.toronto.ca/legdocs/mmis/2017/pw/bgrd/backgroundfile-107515.pdf</ref>. The benefit of porous asphalt in comparison to some other permeable pavements is that it doesn't require proprietary components, joint stabilizing aggregate, nor specialized paving equipment for installation<ref>Speight, J.G., 2016. Asphalt materials science and technology (pp. 437-474). Butterworth-Heinemann is. https://link.springer.com/article/10.1557/mrs.2016.267#article-info</ref>.

[[Permeable pavement|Porous Asphalt]] is an alternative to traditional impervious pavements that allow stormwater to drain through them and into a storage reservoir below. Porous asphalt's performance and integrity is similar to that of other standard asphalt pavements. Porous asphalt contains air pockets, which are created during the development process of the paver due to the inclusion of less fines and [[sand]] content in comparison to traditional asphalt. The "air pockets" or greater void spaces are what allow stormwater to infiltrate through the surface level to the underlying storage [[Reservoir aggregate|reservoir aggregate layers]]<ref>City of Toronto. 2017. Toronto Green Streets Technical Guidelines. Version 1.0. August, 2017. https://www.toronto.ca/legdocs/mmis/2017/pw/bgrd/backgroundfile-107515.pdf</ref>. The benefit of porous asphalt in comparison to some other permeable pavements is that it doesn't require proprietary components, joint stabilizing aggregate, nor specialized paving equipment for installation<ref>Speight, J.G., 2016. Asphalt materials science and technology (pp. 437-474). Butterworth-Heinemann is. https://link.springer.com/article/10.1557/mrs.2016.267#article-info</ref>.

Depending on the native soil properties and site constraints, the system may be designed for full infiltration, partial infiltration, or as a non-infiltrating, filtration and detention practice. They can be used for low traffic roads, parking, driveways, and walk ways, and are ideal where space for other surface BMPs is limited.

Depending on the native soil properties and site constraints, the system may be designed for full infiltration, partial infiltration, or as a non-infiltrating, filtration and detention only practice. They can be used for low traffic roads, parking, driveways, and walk ways, and are ideal where space for other surface BMPs is limited.

The information found here relates to '''Porous Asphalt'''. For costs and information associated with [[Permeable pavements: Life Cycle Costs|Permeable Interlocking Concrete Pavers click here]]. STEP has prepared life cycle costs estimates for each design configuration, based on a drainage area composed of 1,000 m² of conventional asphalt and 1,000 m² of porous asphalt, runoff control target of 25 mm depth and 72 hour drainage period, for comparison which can be viewed below. To generate your own life cycle cost estimates customized to the development context, design criteria, and constraints applicable to your site, access the updated [https://sustainabletechnologies.ca/lid-lcct/ LID Life Cycle Costing Tool (LCCT) here].

The information found here relates to '''Porous Asphalt'''. For costs and information associated with [[Permeable pavements: Life Cycle Costs|Permeable Interlocking Concrete Pavers click here]]. STEP has prepared life cycle costs estimates for each design configuration, based on a drainage area composed of 1,000 m² of conventional asphalt and 1,000 m² of porous asphalt, runoff control target of 25 mm depth and 72 hour drainage period, for comparison which can be viewed below. To generate your own life cycle cost estimates customized to the development context, design criteria, and constraints applicable to your site, access the updated [https://sustainabletechnologies.ca/lid-lcct/ LID Life Cycle Costing Tool (LCCT) here].

==Construction Costs==

==Construction Costs==

[[File:Construction Breakdown PA No Infil.PNG|thumb|right|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - No Infiltration Design, 25 mm Retention''']]

[[File:Construction Breakdown PA No Infil 2023.PNG|thumb|right|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - No Infiltration Design, 25 mm Retention''']]

[[File:Construction Breakdown PA Full Infil.PNG|thumb|left|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Full Infiltration Design, 25 mm Treatment''']]

[[File:Construction Breakdown PA Full Infil.PNG|thumb|left|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Full Infiltration Design, 25 mm Treatment''']]

[[File:Construction Breakdown PA Partial Infil.PNG|thumb|center|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Partial Infiltration Design, 25 mm Retention''']]

[[File:Construction Breakdown PA Partial Infil 2023.PNG|thumb|center|400px|'''Construction Costs Per Unit Drainage Area (CAD$/m²) - Partial Infiltration Design, 25 mm Retention''']]

<small>'''Note:''' Please click on each image to enlarge to view associated construction cost results.</small><br>

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

[[File:25yr LCCT PA Full Infil.PNG|thumb|left|400px|'''Porous Asphalt: Full infiltration''']]

[[File:25yr LCCT PA Full Infil.PNG|thumb|left|400px|'''Porous Asphalt: Full infiltration''']]

[[File:25yr LCCT PA No Infil.PNG|thumb|right|400px|'''Porous Asphalt: Non-infiltrating''']]

[[File:25yr LCCT PA No Infil 2023.PNG|thumb|right|400px|'''Porous Asphalt: Non-infiltrating''']]

[[File:25yr LCCT PA Partial Infil.PNG|thumb|center|400px|'''Porous Asphalt: Partial infiltration''']]

[[File:25yr LCCT PA Partial Infil 2023.PNG|thumb|center|400px|'''Porous Asphalt: Partial infiltration''']]

<small>'''Note:''' Please click on each image to enlarge to view associated life cycle cost results.</small><br>

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

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

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

[[File:50yr LCCT PA Full Infil.PNG|thumb|left|400px|'''Porous Asphalt: Full infiltration''']]

[[File:50yr LCCT PA Full Infil.PNG|thumb|left|400px|'''Porous Asphalt: Full infiltration''']]

[[File:50yr LCCT PA No Infil.PNG|thumb|right|400px|'''Porous Asphalt: Non-infiltrating''']]

[[File:50yr LCCT PA No Infil 2023.PNG|thumb|right|400px|'''Porous Asphalt: Non-infiltrating''']]

[[File:50yr LCCT PA Partial Infil.PNG|thumb|center|400px|'''Porous Asphalt: Partial infiltration''']]

[[File:50yr LCCT PA Partial Infil 2023.PNG|thumb|center|400px|'''Porous Asphalt: Partial infiltration''']]

<small>'''Note:''' Please click on each image to enlarge to view associated life cycle cost results.</small><br>

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

==Cost Summary Tables==

==Cost Summary Tables==

Total life cycle cost estimates for the three porous asphalt configurations vary substantially with the No Infiltration design being highest ($160,519.90), compared to the Partial Infiltration design ($138,144.27), and followed closely by the Full Infiltration design ($131,972.30).

Total life cycle cost estimates over the 50 year evaluation period for the three porous asphalt configurations vary substantially with the No Infiltration design being highest ($260,789.11), compared to the Partial Infiltration design ($237,742.21), and followed closely by the Full Infiltration design ($228,316.69).

It is notable that a sensitivity analysis was conducted in 2019 to compare construction cost estimates generated by the tool to actual costs of implemented projects. '''The analysis found that tool estimates were typically within ±14% of actual construction costs'''<ref>Credit Vally Conservation (CVC). 2019. Life-cycle costing tool 2019 update: sensitivity analysis. Credit Valley Conservation, Mississauga, Ontario. https://sustainabletechnologies.ca/app/uploads/2020/04/LCCT-Sensitivity-Analysis_March2020.pdf</ref>.

It is notable that a sensitivity analysis was conducted in 2019 to compare construction cost estimates generated by the tool to actual costs of implemented projects. '''The analysis found that tool estimates were typically within ±14% of actual construction costs'''<ref>Credit Vally Conservation (CVC). 2019. Life-cycle costing tool 2019 update: sensitivity analysis. Credit Valley Conservation, Mississauga, Ontario. https://sustainabletechnologies.ca/app/uploads/2020/04/LCCT-Sensitivity-Analysis_March2020.pdf</ref>.

[[File:Kane-porous.jpg|thumb|800px|An example of installed porous asphalt in a designated biking lane, with curb cut inlets leading to adjacent bioswale features, located in the in the City of Gresham, Oregon (Source: Sightline Institute, 2012<ref>Sightline Institute, 2012. Surprisingly Ambitious Permeable Projects. Written by Lisa Stiffler. February 22, 2012. Accessed Dec. 16, 2022. https://www.sightline.org/2012/02/22/surprisingly-ambitious-permeable-projects/</ref>).]]

[[File:Kane-porous.jpg|thumb|800px|An example of installed porous asphalt in a designated biking lane, with curb cut inlets leading to adjacent bioswale features, located in the in the City of Gresham, Oregon (Source: Sightline Institute, 2012<ref>Sightline Institute, 2012. Surprisingly Ambitious Permeable Projects. Written by Lisa Stiffler. February 22, 2012. Accessed Dec. 16, 2022. https://www.sightline.org/2012/02/22/surprisingly-ambitious-permeable-projects/</ref>).]]

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

[[File:Design Table PA Full Infil update 2023.PNG|700px]]<br>

</br>

</br>

===Partial Infiltration===

===Partial Infiltration===

[[File:Design Table PA Partial Infil.PNG|700px]]<br>

[[File:Design Table PA Partial Infil 2023.PNG|700px]]<br>

</br>

</br>

===Non-Infiltrating/filtration only===

===Non-Infiltrating/filtration only===

[[File:Design Table PA No Infil.PNG|700px]]<br>

[[File:Design Table PA No Infil update 2023.PNG|700px]]<br>

==References==

==References==