Stormwater Quality Design Manual (May 2007) - City of Sacramento ...

Runoff Reduction Control Measure Fact SheetPorous PavementWoven geotextile fabric meeting:ASTM D4751-AOS of 50-70ASTM D4633 min. trapezoidal tear strength 100 x 60 lbs.Minimum COE specified open area of 4%.When certified tests show permeability rates of less than 60minutes per inch of drawdown under the PP bottom andinfiltration is allowed, eliminate the bottom sand layer andunderdrains.When Type C soils are present and when infiltration isallowed, unless permeability show otherwise, eliminate thebottom sand layer, use underdrains and geotextile linerinstead of an impermeable one under the gravel. When theunderlying soils are Type D or expansive, use underdrainsand 16 mil minimum thickness impermeable liner under andon sides of the pavement sand and gravel media.Woven geotextile fabric meeting:ASTM D4751-AOS of 50-70ASTM D4633 min. trapezoidal tear strength 100 x 60 lbs,Minimum COE specified open area of 4%.Figure PP-1. Typical Pervious Concrete Sections*(Source: adapted from Denver) *Installation specifications may vary by site; check with local permitting agencyStormwater Quality Design Manual for the Sacramento and South Placer RegionsMay 2007PP-5