Precast Porous Concrete Panel (PPCP)

• Reduces impermeable surface, thereby increasing water infiltration
• Reduces peak sewer discharge during storm events
• Reduces likelihood of ponding and slick or icy conditions
• Helps reduce urban heat island effect

See General Guidelines

• Extra care must be taken where there is water-sensitive sub-surface infrastructure
• Only certain soil types are appropriate as sub-bases for infiltration
• Porosity of the concrete can convey harmful chemicals into the soil
• Sand and certain chemical de-icers should not be applied to surface
• Contractors should be certified to install Precast Porous Concrete Panels
• Slump and air content tests are not applicable to Precast Porous Concrete Panels
• Lower strength material than standard concrete

• Precast Porous Concrete Panels are a standard material when installed by the City within a parking lane
• Most effective on slopes less than 5%
• Must have adequate sub-surface conditions to detain stormwater and level bottom to allow for uniform infiltration
• Avoid sites on truck routes and principal arterial roadways
• Avoid sites where there is potential for soil and groundwater contamination
• Do not site within Industrial Business Zones, or on block faces on main and side streets of M1, M2, M3, and C4 throughC8 zoning districts
• Do not site within existing bike lanes or crosswalks
• Not recommended for implementation over significant underground utility corridors

No specification source

See design guidance for Unpigmented Concrete
 

• Typically an 8- to 24-inch open graded stone infiltration bed is recommended
• Generally 4 – 8 inches thick
• Precast Porous Concrete Panels should maintain a 15 – 25% void content ratio
• Bottom of infiltration bed should be at least 2 feet above high water table and 2 feet above bedrock
• Maintain 6 feet of clearance from the edge of sewer mains, 3 feet 6 inches from the edge of water mains older than 50 years, and 2 feet from the edge of water mains 50 years or newer
• PPCP should not be sited within a bus stop. Maintain 200 feet of clearance behind a bus stop and 20 feet in front of a bus stop
• Do not install PPCP within 25 feet of subway lines and railroads
• Avoid siting within intersections. Extend the corner of the property line to the curb and maintain a clearance of at least 15 feet from the extension line in either direction

• The City will maintain this material in specific circumstances; generally when used within the parking lane
• Use of this material beyond city-led installations will require a maintenance agreement
• Requires routine vacuuming of surface using a regenerative air sweeper to restore permeability

Rego Park, Queens