Remediation of Stormwater Pollutants by Porous Asphalt Pavement

Anand Jayakaran,John Stark,Curtis Hinman,Thorsten Knappenberger

doi:10.3390/w11030520

Anand Jayakaran, John Stark + Show 2 more

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https://doi.org/10.3390/w11030520

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Journal: Water	Publication Date: Mar 13, 2019
Citations: 17	License type: CC BY 4.0

Affiliation: Washington State University, Auburn University

Abstract

Porous Asphalt (PA) pavements are an increasingly adopted tool in the green stormwater infrastructure toolbox to manage stormwater in urbanized watersheds across the United States. This technology has seen particular interest in western Washington State, where permeable pavements are recognized as an approved best management practice per the National Pollutant Discharge Elimination System (NPDES) municipal stormwater permit. Stormwater effluent concentrations from six PA cells were compared with runoff concentrations from three standard impervious asphalt cells to quantify pollutant removal efficiencies by porous asphalt systems. Additionally, the effects of maintenance and pavement age on pollutant removal efficiencies were examined. Twelve natural and artificial storms were examined over a five-year period. Street dirt and pollutant spikes were added to the pavements prior to some storm events to simulate high loading conditions. Results from this work show that porous asphalt pavements are highly efficient at removing particulate pollutants, specifically coarse sediments (98.7%), total Pb ( 98.4%), total Zn (97.8%), and total suspended solids (93.4%). Dissolved metals and Polycyclic Aromatic Hydrocarbons (PAH) were not significantly removed. Removal efficiencies for total Pb, total Zn, motor oil, and diesel H. improved with the age of the system. Annual maintenance of the pavements with a regenerative air street sweeper did not yield significant pollutant removal efficiency differences between maintained and unmaintained PA cells.

Highlights

Stormwater pollution is a critical source of impairment to receiving water bodies in the United States
The differential removal of metals by porous asphalt systems is attributed to particulate affinity [31], where metals that are primarily in the particulate phase tend to adsorb to sediments that are trapped within the pavement system, and removed from effluent stormwater
The ability of six porous asphalt pavement cells to remove stormwater pollutants was evaluated over five years by comparing analyte concentrations emanating from elevated drains and under drains, with corresponding concentrations from three proximal impervious asphalt surfaces

Summary

Introduction

Stormwater pollution is a critical source of impairment to receiving water bodies in the United States. In western Washington State, stormwater is a principal threat to the Puget Sound ecosystem [1]. Green Stormwater Infrastructure (GSI) is a system of practices that aim to mitigate both water quantity and quality issues employing ecosystem processes to treat stormwater close to its source [2,3,4]. In western Washington State, GSI is a requirement of the National Pollutant Discharge Elimination. System (NPDES) municipal stormwater permit for certain new and redevelopment projects [9]. An important tool in the GSI toolbox is permeable pavements, a system that sees widening adoption in municipalities across the United States [10,11].

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