Paving and Asphalt
Use Permeable Interlocking Concrete Pavers
What Is It?
EV Studio
Permeable interlocking concrete pavers (PICPs) leave highly permeable void spaces or joints between solid, high-strength pavers to allow for water infiltration. These filled joints can allow for infiltration rates of up to 50 inches per hour with regular maintenance (e.g. street sweeping/vacuuming and refilling of displaced gravel) and 3-4 inches/hour without, though in practice, infiltration rates will depend on the permeability of the subgrade soil. PICPs meet US EPA stormwater best management practice criteria for parking, road, and pedestrian surfaces.
PICPs have very high load bearing strength, often exceeding 1 million lbs/sq ft, more than double the compression strength of concrete slabs. PICPs come in a wide variety of shapes, sizes, and colors, allowing for a diverse range of applications while preserving the surrounding aesthetic. The maximum slope of PICPs is higher than that of other permeable pavements, allowing for a slope of up to 12% while maintaining infiltration.
Benefits
- Enhances groundwater infiltration while reducing stormwater runoff volume, rate, and pollutants.
- Light-colored PICPs can reduce urban heat island through increased reflectivity and evaporative cooling
- Resists frost heaving and cracking, since there are natural gaps in the surface where ice can easily expand and quickly melt through
- Available in wide range of colors and shapes to preserve urban aesthetic
- Very high load bearing strength
- Easy to repair; units can be easily removed and reset
- Reduces occurrence of black ice/freezing puddles in cold climates; requires less applied de-icers
- Promotes tree and other vegetation growth adjacent to or within PICP plot
Drawbacks
- Pollutants and deicing salt can infiltrate groundwater—should not be installed in areas where hazardous material spills are possible
- Can be more expensive than other permeable pavements
Regulatory Impacts and Requirements
Potential regulatory touchpoints in Boston and Massachusetts include:
- Boston Groundwater Trust
- Boston Water and Sewer Commission
- Local Utilities
- Boston Public Works Department
- Public Improvement Commission
- Zoning Board of Appeals
- Architectural Access Board
- MA Historical Commission/Boston Landmarks Commission
Financing Options, Incentives, and Rebates
- Mass.gov:
- Clean Water State Revolving Fund (SRF)
- Coastal Pollutant Remediation (CPR) Grant Program
- Section 319 Nonpoint Source Competitive Grant (Funding provided under federal Clean Water Act)
- 604b Water Quality Management Planning Grant (Funding provided under federal Clean Water Act)
- Drinking Water Supply Protection Grant Program
- Newton, MA: Municipal stormwater abatement service fees
News
- “Permeable paving: the solution to icy roads and flooding?” Citymetric, November 2014
- "This concrete can absorb a flood," SmithsonianMag, October 5, 2015
Resources
- Interlocking Concrete Pavement Institute (ICPI): Permeable Pavers
- California Coastal Commission: Permeable Pavement
- US EPA: See pg. 8 of the Cooling Pavements Chapter of their Heat Island Compendium
- Seattle Right of Way Manual: Permeable Pavement Comparison Guide
- University of Maryland: Permeable Pavement Fact Sheet
Project Examples
- The largest PICP project in the US helped a Toyota dealership in Vancouver, WA, earn LEED certification.
- ICPI: Project Profiles
A Sample of Providers
The Interlocking Concrete Pavement Institute provides technical information for PICP best practices and maintains a database of PICP manufacturers and contractors. Search for manufacturers here, contractors here, and distributors here.
