As protecting natural resources continues to rise in importance, facilities professionals everywhere are gaining interest in the advantages porous paving can offer. This stormwater-management solution has even been deemed a best management practice (BMP) by the U.S. Environmental Protection Agency for its ability to reduce runoff. In commercial applications, porous pavement is most commonly used as an alternative to imperviously paved sidewalks and parking areas, and can either be porous asphalt or pervious concrete.
The Skokie, IL-based Portland Cement Association (PCA) recently reported that interest in this solution is rising and explained why it’s so effective. “Pervious concrete is an open void material designed to allow rainwater to filter through the paved surface into the ground or a storage container rather than settling on the surface,” describes the association. The PCA will be demonstrating this innovative technology with a full display at the 2007 American Institute of Architects (AIA) National Convention and Design Exposition later this week.
Additional benefits include the elimination of retention ponds, swales, and other stormwater management devices that require dedicated land, notes the National Ready Mixed Concrete Association, Silver Spring, MD. The EPA, in its Storm Water Technology Fact Sheet on Porous Pavement, reports the following pros and cons.
Advantages to using porous pavement include:
- Water treatment by pollutant removal.
- Less need for curbing and storm sewers.
- Improved road safety because of better skid resistance.
- Recharge to local aquifers.
- Many pavement engineers and contractors lack expertise with the technology.
- Porous pavement has a tendency to become clogged if improperly installed or maintained.
- There is some risk of contaminating groundwater, depending on soil conditions and aquifer susceptibility.
- Fuel may leak from vehicles and toxic chemicals may leach from asphalt and/or binder surface. Porous pavement systems are not designed to treat these pollutants.
- Some building codes may not allow for its installation.
- Anaerobic conditions may develop in underlying soils if the soils are unable to dry out between storm events. This may impede microbiological decomposition.
In addition to this assessment, the staff of the Lake Superior Streams project in Duluth, MN, list reduced flooding, thermal pollution, and pavement ice build-up as additional benefits.
To find out more about why stormwater runoff is a problem, visit the EPA’s website.