Assessing the potential for restoration of surface
permeability for permeable pavements through
maintenance
Jennifer Drake and Andrea Bradford
ABSTRACT
Permeable pavements (PPs) have been in use as stormwater management systems in Canada and
the United States for over 20 years. After years of exposure to sediment and debris build-up, surface
clogging reduces the infiltration of stormwater and inhibits the hydraulic and environmental
functions of the pavement. Removal of surface material has been shown to restore infiltration but the
majority of studies have been limited to small-scale testing. This paper presents the results of small-
and full-sized equipment testing aimed at restoring surface permeability, including the first testing of
regenerative-air and vacuum-sweeping streetsweepers in Ontario. Maintenance achieved partial
restoration of PP surface permeability. Post-treatment surface infiltration rates displayed large spatial
variability, highlighting that localized conditions throughout the pavement have a confounding
influence on the overall effectiveness of maintenance. The impact of maintenance may be improved
by establishing regular cleaning intervals and developing instructional guidelines for pavement
owners and equipment operators.
Jennifer Drake (corresponding author)
Department of Civil Engineering,
University of Toronto,
35 St. George St,
Toronto,
ON, M5S 1A4,
Canada
E-mail: jenn.drake@utoronto.ca
Andrea Bradford
School of Engineering,
University of Guelph,
50 Stone Rd,
Guelph,
ON, N1G 2W1,
Canada
Key words | infiltration, maintenance, permeable pavements, restoration, stormwater, urban
drainage
INTRODUCTION
Permeable pavement (PP) systems are beneficial stormwater
management practices which improve stormwater quality
and mitigate the hydrologic effects of urbanization. Despite
over 20 years of research and demonstration, use of PP sys-
tems is not widespread throughout many parts of Canada
and the United States. A commonly cited concern is the
assumption that pavements will clog rapidly resulting in a
loss of infiltration and stormwater management capacity
within a relatively short time period. PPs remove particulate
pollutants, such as suspended sediments and associated
heavy metals and nutrients, from stormwater through the
processes of filtration and sedimentation (Brown et al.
). These removal mechanisms capture and trap particu-
lates inside the voids of the pavement and aggregate layers.
Over time, accumulation of materials can decrease surface
permeability and limit the rate of stormwater infiltration
(Pezzaniti et al. ).
Removal of fines at and near the pavement surface has
been shown to provide partial or full restoration of surface
permeability (Kresin et al. ; James & Gerrits ;
Lucke & Beecham ). In recent years, researchers have
tested a variety of maintenance techniques on PPs (Van
Duin et al. ; Chopra et al. a, b; Henderson &
Tighe ) but consensus about best maintenance practices
and their overall effectiveness has not been achieved. While
industry organizations such as the Interlocking Concrete
Pavement Institute (ICPI) recommend vacuum-sweeping,
some researchers (e.g. Chopra et al. a; Henderson &
Tighe ) have recommended pressure-washing. Testing
of vacuum-sweeping equipment has only been performed
on a few occasions, based on the literature reviewed by the
authors. Field tests performed by Chopra et al.(b) with
an Elgin Whirlwind MV truck on five artificially clogged
PPs showed that vacuum-sweeping restores some surface per-
meability. Van Duin et al. tested a Schwarze Model
A800 vacuum-sweeper on Unilock Eco-Stone permeable
interlocking concrete pavement (PICP) and porous asphalt
after one winter of normal traffic usage and road sanding
practices. The streetsweeper was unable to restore the surface
permeability of the porous asphalt. Vacuum-sweeping was
1950 © IWA Publishing 2013 Water Science & Technology | 68.9 | 2013
doi: 10.2166/wst.2013.450
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