A Meta-Analysis of Contaminant Removal from Urban Stormwater by Permeable Pavements

Pollution resulting from urban stormwater runoff has become a major problem for cities. The use of permeable pavements that allows stormwater infiltration into soil layers underneath the pavement system is considered a paradigm shift from conventional use of impervious pavements. In addition to reducing the runoff load on stormwater drainage systems, it contributes to the reduction of contaminant loads in the infiltrated water which would have otherwise ended in water streams and potentially cause environmental problems (such as deteriorated fish habitats). Recent research has expanded on the investigation of permeable pavements to include its impact on water quality in addition to the typical analysis pertaining to its mechanical strength and durability. In this study, a meta-analysis of the impact of permeable pavements on the infiltrated stormwater quality is conducted. The analysis focused on recent research (2010-2020) that has specifically investigated the reduction of certain contaminant concentrations in stormwater infiltrating through permeable pavements. Results were classified based on the type of contaminant investigated (heavy metals, nutrients, and organic content) considering the difference in composition and properties (e.g., pore volume) of tested permeable pavement systems. It was observed that lab and field studies investigating stormwater contaminant removal were mainly conducted for pervious concrete and porous asphalt. The analysis closed with insights into limitations and knowledge gaps that need to be addressed to better understand the effective use of permeable pavements in stormwater quality management.