Additional considerations for permeable pavement
Contents
Compliance with the Americans with Disabilities Act (ADA)
All permeable pavements are ADA compliant. PICP is compliant if designs are used with joints less than ½ inch wide.
Groundwater protection and underground injection control permits
The Safe Drinking Water Act regulates the infiltration of stormwater in certain situations pursuant to the Underground Injection Control (UIC) Program, which is administered either by the US EPA or a delegated state groundwater protection agency. The US EPA (USEPA 2008) determined that permeable pavement installations are not classified as Class V injection wells since they are always wider than they are deep. There may be an exception in karst terrain if the discharge from permeable pavement is directed to an improved sinkhole, although this would be uncommon.
Air and runoff temperature
Permeable pavement appears to have some value in reducing summer runoff temperatures which can be important in watersheds with sensitive cold-water fish populations (Hunt 2011). The temperature reduction effect is greatest when runoff is infiltrated into reservoir layer when underdrains are used. All permeable pavements exhibit cooler summer temperatures than their impervious counterparts. For example, a recent study showed that porous asphalt showed lower nighttime temperatures when compared with materials that have a similar or higher albedo. This was attributed to the insulating properties of porous asphalt due to its high air void content (Stempihar 2011). Pervious concrete and PICP can meet the solar reflectance index (SRI) of 29.
Sustainable rating systems
All permeable pavements support sustainable rating systems such as LEED and others plus sustainable transportation rating systems such as those published by the Institute for Sustainable Infrastructure (Envision), Federal Highway Administration (INVEST), and the University of Washington (Greenroads).
Certification
As previously noted, the pervious concrete and PICP industry associations offer education and certification of permeable pavement contractors, i.e., the National Ready Mix Concrete Association (NRMCA) and the Interlocking Concrete Pavement Institute (ICPI). Porous asphalt does not require unique materials and can be installed by most paving equipment. In addition, all plants producing hot-mix asphalt are required to be certified by MnDOT. Industry-trained and experienced supervisory personnel should be required on all jobsites and requirements written into project specifications. A specifications requirement can be contractor submittals demonstrating experience with previous projects.
For design professionals, industry and professional associations offer in-person and online continuing education programs on design, construction and maintenance of permeable pavements. Many of these programs are registered with continuing education programs offered for civil engineering professional development hours, the American Institute of Architects and the American Society of Landscape Architecture continuing education systems, and the Green Building Certificate Institute Credential Maintenance Program for LEED® accredited professionals. Designers are encouraged to participate in these programs.
Industry associations provide literature and design software for design professionals. The National Asphalt Pavement Association offers “Porous Asphalt Pavements for Stormwater Management, Design, Construction, and Maintenance Guide” (Hansen 2008). The Minnesota Asphalt Pavement Association has guidance on their website. The American Concrete Pavement Institute has design software called PerviousPave for design of pervious concrete pavement. The software can be downloaded from their website. Specifications for the design of pervious concrete are provided by the American Concrete Institute (ACI) in ACI 522.1-08 “Specification for Pervious Concrete Pavement”. A report titled ACI 522R-10 “Report on Pervious Concrete” is also available. ICPI offers a course called “Permeable Interlocking Concrete Pavements” covering design, specifications, construction, and maintenance. ICPI also offers Permeable Design Pro software for PICP structural and hydrologic design.
Related articles
- Overview for permeable pavement
- Types of permeable pavement
- Design criteria for permeable pavement
- Construction specifications for permeable pavement
- Assessing the performance of permeable pavement
- Operation and maintenance of permeable pavement
- Calculating credits for permeable pavement
- Additional considerations for permeable pavement
- References for permeable pavement
- Fact sheets for permeable pavement