Evaluation of Various Types of Permeable Pavements with respect to Water Quality Improvement and Flood Control

Abstract

In North Carolina and several other U.S. states, all permeable pavements arecurrently considered to have similar capabilities in reducing runoff, but are not credited withimproving water quality. Previous research conducted by the North Carolina State University onone particular permeable block pavement type has shown that when compared to runoff from anadjoining asphalt lot, permeable pavement exfiltrate contained significantly lower concentrationsof phosphorous and zinc, as well as reductions in total nitrogen. To further test variouspermeable pavement designs, a parking lot consisting of four different types of permeablepavements and standard asphalt was constructed in Kinston, NC. The permeable pavementsections consist of permeable interlocking concrete pavers (PICP) with 8.5 % void space, PICPwith 12.9 % void space, concrete grid pavers (CGP), and porous concrete (PC), each coveringa 1200 sq. ft. area with a 10 in. gravel storage layer. The purpose of this study is to evaluateand compare the effects of each pavement type on water quality and runoff reduction.Conclusions on the difference in reduction between each pavement type have not beendetermined. Site analyses on every rainfall event will be conducted beginning January, 2006and will continue for one year. As a result of the Kinston study, it is expected that the state ofNorth Carolina will be able to make an informed judgment on how much pollutant removal creditpermeable pavements should receive when implemented as stormwater best managementpractices. Also, this study can be used to determine whether or not stormwater credit shouldvary based on pavement type.