Changes

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 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 conducted life cycle costs estimates for each of permeable pavements 3 design configurations which can be viewed below. To design your own life cycle cost estimates that can be adapted to fit your project budget and unique development needs access the updated [https://sustainabletechnologies.ca/lid-lcct/ LCCT Tool 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].

===Design Assumptions===

===Design Assumptions===

Porous asphalt is ideal for sites with limited space and projects such as low traffic roads, parking lots, driveways and walkways. Components include: a porous asphalt surface, a stabilizer course, and a base layer for storage.

Porous asphalt is ideal for sites with limited space and projects such as low traffic roads, parking lots, driveways and walkways. Components include: a porous asphalt surface, a stabilizing base layer of aggregate, and a sub-base layer of aggregate for water storage.

Additional components include an underdrain to remove excess water and surface drains to deal with runoff flows in excess of design capacity.

Additional components include an underdrain to remove excess water and surface drains to safely convey flows in excess of the storage capacity of the design.

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:

*Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and vacuum sweeping annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ surface infiltration rate testing.

*Operation and maintenance (O&M) cost estimates assume annual inspections, removal of trash and debris twice a year, and vacuum sweeping annually. Verification inspections are included every 5 years to confirm adequate maintenance, and every 15 years to confirm adequate drainage performance through in-situ surface infiltration rate testing.

* Impervious drainage area to permeable surface area (I:P area) ratio of 1:1

* Impervious drainage area to permeable surface area (I:P area) ratio of 1:1

* Default Stabilizing course/ Choker layer (19 mm dia. clear stone) depth of 50 millimetres.

* Default base layer aggregate (19 mm dia. clear stone) depth of 50 millimetres.

* Default Asphalt depth of 110 millimetres.

* Default asphalt depth of 110 millimetres.

* Default Stone resevoir (50 mm dia. clear stone) depth of 230 millimetres.

* Default sub-base layer (or stone reservoir) aggregate (50 mm dia. clear stone) depth of 230 millimetres.

* A 150 mm diameter perforated underdrain pipe is included in Partial Infiltration and No Infiltration design configurations only.<br>

* A 150 mm diameter perforated underdrain pipe is included in Partial Infiltration and No Infiltration design configurations only.<br>