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==Total Cost & Design Summary==

==Total Cost & Design Summary==

As previously discussed the three [[Permeable pavement]] configurations total cost summary vary greatly dependent on whether you want your feature to possess full infiltration, no infiltration, or partial infiltration. In short the most expensive of these options is the '''Permeable Pavement: No infiltration''' option ($187,356.33 vs. $168,085.10 - partial infiltration and $162,491.78 - full infiltration). The same can be said for construction + associated retrofit costs with each configuration design ($217,333.34 vs. $194,978.72 - partial infiltration and $188,490.47 - full infiltration). This configuration costs more than the other two predominantly due to the addition of an over 1,100m² [[Liner|Impermeable membrane]] (0.762 mm High Density Polyethylene-HDPE), which costs $24,181.47. This difference in price accounts for all three configurations possessing the exact same surface area footprint of 1,000m². As a reminder, it is important to understand your site's surrounding native soil infiltration rate to ensure you are selecting the appropriate design and if your site is located within a [[Source Water Protection#LID Site Considerations|WHPA]] or [[Pollution prevention|Pollution hotspot]], thus requiring a non-infiltration practice such as the aforementioned configuration of a permeable pavement feature. <br>

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).

A final note regarding the accuracy of the LCCT. A follow up sensitivity analysis study was conducted by CVC & STEP back in 2019 to test the tool's accuracy. The analysis took designs from 6 completed projects (4 [[bioretention]], 1 [[permeable pavement]], and 1 [[infiltration trench]]), and ran them through the tool comparing construction costing results from the LCCT to actual construction costs for the projects. The accuracy target set for the tool was plus-or-minus 30% of actual construction costs.<br>

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>.

 

'''The analysis found that the tool was on average (±14%) to 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>

===Full Infiltration===

===Full Infiltration===

[[File:PICPchicago.jpg|thumb|500px||Permeable Interlocking Concrete Pavement (PICP) on a narrow road between buildings in Chicago (Source: ICPI)]]

[[File:Kane-porous.jpg|thumb|500px||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 PP Full Infil.PNG|700px]]<br>

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

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===Partial Infiltration===

===Partial Infiltration===

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

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

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

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

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

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

==References==

==References==