PERMEABLE INTERLOCKING CONCRETE PAVEMENT (PICP)

MUNICIPAL OFFICIALS FACT SHEET

Storm water Benefits

• Reduces pollutants from rainwater runoff

• Complements buildings and visually unifiesstreetscape, many colors available

• LEED®points eligible for Sustainable Sites,Water Efficiency, Materials & Resources and/or Innovative Design; Earns Green Globepoints

• Meets U.S. Environmental Protection Agencystorm water performance criteria as astructural best management practice (BMP)while providing parking, road and pedestriansurfaces

• Helps meet local, state and provincialstormwater drainage design criteria andprovides compliance with the U.S. NationalPollutant Discharge Elimination System(NPDES) regulations

• Reduces runoff from common rainstormsby as much as 100%; eliminates surfacepuddles and local flooding

• Promotes street tree survival

• Snow melts faster on permeable pavementand drains, reducing ice hazards

• Snow plow with typical snow removalequipment; reduce winter ice hazards, de-icing salt use and snow removal costs.

• 50 year life-cycle for surface

• Compatible with underground stormwaterstorage systems, many slower-draining claysoils and cold climates

Governments may offer tax incentives, utilityfee reductions, expedited permitting or ademonstration project to encourage use.

PICP's can eliminate street storm drains andsewer pipes as in this redevelopment projectin Seattle,WA.

ICPI~INfERL(J[KING CONCRETE

PAVEMENT INSTITUTE ®

3 1/8 in. (80 mm) thick~pavers with permeable

joints

Open-graded beddingcourse

~Open-graded basecourse (OGB)

•..•• Open-graded subbaseon non-compacted soilsubgrade

Permeable interlocking concrete pavement(PICP) with base and subbase for infiltrationand storage

Parking at this recreation site on SouthWhidbey Island, WA eliminates runoff duringmost rainstorms.

APPLICATION OPPORTUNITIES• Public Projects: Office plazas, parks, sidewalkreplacement, street tree planting areas, park-ing lots and outdoor seating areas

• Private Projects: Parking lots, parks, drive-ways, parking bays on roadways, subdivisionroads and sidewalks

• Public-Private Partnerships & Redevelop-ment Sites: Parking areas, plazas and publicspaces and sidewalks

communify Development Tool

I LID INTEGRATED WITH PICP ]

Permeable Interlocking Concrete Pavement:A Low Impact Development Tool

PICP Meets LID Goals

• Conserves on-site space: roads,parking, stormwater infiltrationand retention all combined into thesame space creating more greenspace or building opportunities

• Preserves wooded areas thatwould otherwise be cleared forstormwater detention or retentionponds

• Increases site infiltration that helpsmaintain pre-development runoffvolumes, peak flows and time ofconcentration

• Promotes tree survival and growth

• Contributes to urban heat islandreduction through evaporation andreflective, light colored pavers

• Highly visible, cost-effectiveexemplary demonstration of acornerstone LID technique forpublic and private development

Extensive green roof retrofit

Disconnected downspoutwaters infiltration planter

Intensive green roof retrofit

Awning retrofit cools sidewalk, -directs water topermeable interlockingconcrete pavement

Permeable interlockingconcrete pavers (PICP) intravel lanes with storagecapacity built into thepavement system

Permeable interlockingconcrete pavers inparking lanes withstorage capabilitybuilt into the pavementsystem

Street tree ininfiltration trench2.5 feet (.75 m) deepwith 4 in. (100 mm)underdrain tied tostorm sewer

2

I

Utilities in center laneunder water storage media

PICP Supports LID Principles

1. Conserve vital ecological and natural resources: trees,streams, wetlands and drainage courses

2. Minimize hydrologic impacts by reducingimperviousness, conserving natural drainage courses,reducing clearing, grading and pipes

3. Maintain pre-development time of concentration forrunoff by routing flows to maintain travel times anddischarge control

4. Provide runoff storage and infiltration uniformlythroughout the landscape with small, on-site decentralizedinfiltration, detention and retention practices such aspermeable pavement, bioretention, rain gardens, openswales and roof gardens

5. Educate the public and property owners on runoff andpollution prevention measures and benefits

Municipal civic goals may be met usingPICP as part of an integrated approach todevelopment and redevelopment.

--If--t' Gutter flowsdirectedinto bioretentionmedia alongthe gutter route

'----- Bioretention celladjacent to PICP

Curbs with curb cuts directestreet planters (Planter width varies,3 ft. (.9 m) minimum)

PICP as part of an LID approach to streetscape development

CONSTRUCTION AND PROJECT EXAMPLES

Aggregate base is spread and compacted;pavers are delivered ready to install. Afterplacement of bedding course, joints and/oropenings are filled with small aggregate andthe pavers are compacted. Joints may be filled Typical PICP cross sectionmechanically as shown.

Prepared subgrade for 20,000 sf (2000 m+)Portland, OR street retrofit with PICP

Base constructionuses locally availablematerials.

Mechanicalinstallation speedsconstruction.

Portland, OR street project with PICPparking lanes

Concrete Pavers

Permeable Joint MaterialOpen-gradedBedding Course

Underdrain(as required)

Optional GeotextileUnder Subbase

Uncompacted Subgrade Soil

Chicago Green Alley Program before and after PICP installationGreen Alleys are being implemented to manage storm water, reduce combined sewer overflows,reduce urban heat in urban areas, and conserve enerqy. Photos: Courtesy of the City of ChicagoI-----~ 3

Volume Reduction

• PICP significantly reduces runoff from moststorms.

• Runoff volume reductions relieve floodingin storm sewers operating at capacity andrelieve sewage treatment plants receivingcombined storm and sanitary waste flows.

• Reduced runoff can reduce sewer overflowsand stream bank erosion.

Peak Flow Reduction

• Promotes stream and lake health withdecreased erosion

• Reduces water pollution by reducingcombined sewer overflow frequency

• Reduces the need for continuous expansionof drainage infrastructure

Additional Benefits

• Cooler than conventional pavements

• ADA compliant

• May be used on slop.ed site with properdesign

• Simplified surface and subsurface repairsby reinstating the same paving units; nounsightly patches or weakened pavementfrom utility cuts

• Can be used for traffic calming

Water Quality Improvement

• 80% or greater TSS removal

• Preserve and increase drinking and recreationalwater supplies; preserve aquatic and wildlifehabitats.

• Gain recognition for innovative design throughsustainable BMPs

FAQSCan PICP be used on clay soils? Yes. Even in claysoils, PICP reduces runoff and helps to capture "firstflush" runoff and reduce pollution.

Can PICP be used to replace every kind ofpavement? PICP is best suited for use in areas of lowspeed traffic such as parking lots, residential streets,driveways, patios, plazas, sidewalks and parking laneson busier travelways. Nevertheless, PICPhas been suc-cessfully used even under heavy commercial loads.

Will PICP enhance property values? The data frominstalled PICPprojects indicates that PICPmeetsmultiple criteria for project success including enhancingproperty values.

Is Maintaining PICP difficult? No. PICPcan be main-tained through street sweeping and vacuuming based onperiodic inspection.

REFERENCESFerguson, B. K. Porous Pavements. Boca Raton, FL:CRCPress, 2005.

Smith, David R. Permeable Interlocking ConcretePavements: Selection. Design. Construction •Maintenance, Washington,DC:ICPI 3rd ed., 2006.www.icpi.org.

For more information pertaining to permeableinterlocking concrete pavement, please visit theInterlocking Concrete Pavement Institute (icpi.org)or the Low Impact Development Center(Iowimpactdevelopment.org) .

Other Fact Sheets available for Developers,Design Professionals and Schools/ Universities