40 HEALTH AND SANITATION
Innovative solutions to
water challenges bring new
ideas to industry
By
Matt Chapuran
It has become common to talk about the impact of climate
change not upon the current generations, but on the generations
yet to come. Perhaps then it’s fitting that multiple initiatives are
proliferating, aimed at addressing stormwater management.
GP Russ Chaney, IAPMO CEO
In the spirit of the
sharing of unique
experiences that shape
the plumbing industries
in our respective nations,
the following article
looks at the problems
and opportunities that
stormwater management
presents. Written by
IAPMO correspondent Matt
Chapuran, it is the next in
a regular series of similar
articles that will run in
Plumbing Africa.
“Stormwater pollution in urban centres is one of the
biggest sources of water pollution in the country,”
says a spokesperson for the US Environmental
Protection Agency. “Green infrastructure provides
tools to address the threat.”
Existing stormwater systems are being overwhelmed with
more frequent and intense storms. As rainwater floods
drainage systems, the run-off carries sewage into other bodies
of water, including freshwater reservoirs. Along the way, this
run-off gathers chemicals from the ground, such as oil dripped
from cars.
However, because the transportation and treatment of water
requires massive installation, creating change on a systemic
level can often be challenging. “Water is the oldest industry
on the planet, and it’s also the slowest to innovate,” says
Ryan Vogel of PureBlue, a company that incubates many
young companies seeking to profitably address the issues of
stormwater pollution and wastewater management.
Mitigation can take the form of rain gardens, trenches, and
redirection. Toronto’s Green Roof Bylaw began requiring
the incorporation of green roofs into the design of new
construction projects that are greater than 2 000m² in gross
square footage, and requires coverage of between 20-60%
of the available area. For more than ten years, the efficacy of
this approach has been studied at the University of Toronto’s
Green Roof Innovation Testing Laboratory, known as the GRIT
Lab, which carries as its charge “the goal of investigating
the environmental performance associated with such ‘green’
and ‘clean’ technologies as green roofs, green walls, and
photovoltaic arrays.
‘Green’ roofs
“We test aspects of green roofs, using a more evidencebased
approach,” says GRIT Lab’s Professor Robert Wright.
He says that a rooftop garden as simple as a grassy
surface will release water more slowly, easing the stress
on sewage systems that have often been designed for
smaller populations or less density. The gardens can also
reflect sunlight, reducing urban heat and the demand on
increasingly overtaxed HVAC systems.
When incorporated into the design concept of the building,
rooftop gardens can even yield small crops like specialty
herbs, vegetables, wildflowers or blueberries. A local
Torontonian had even begun harvesting and serving honey
from bee colonies installed in a green roof until concerns
were raised that construction from neighbouring buildings
were introducing too much lead dust into the colony, tainting
the honey. Rooftop cisterns can be used to provide irrigation.
With tongue only slightly in cheek, Wright suggests that as
other neighbourhood regulations shift, other specialty herbs
might find their way to rooftop gardens, where they can be
securely grown.
The GRIT Lab’s work has included examining soil quality
and depth and how both can impact the utility of the rooftop
garden, including what organic material might be best to
attract biodiversity or retain water. “The soil of a rooftop
garden can also become oversaturated,” Wright says, “and
when it does, the water begins to sheet off, just like your
lawn after a particularly heavy rain.”
The rooftop gardens promise improved air quality and bring
increased biodiversity. Wright has seen rooftop gardens become
a nesting site for migrating birds. Allowing nature to reclaim
an aspect of the urban environment can improve quality of life,
creating positive feelings about city living. Wright imagines that
this trend will only increase with more vertical forests, including
balcony trees, and other attempts to incorporate biodiversity and
green design into urban development.
More innovations
More innovation is coming at the collegiate level. Since 2012,
the EPA has sponsored the Campus RainWorks Challenge, “a
green infrastructure design competition for American colleges
www.plumbingafrica.co.za @plumbingonline @plumbingonline @PlumbingAfricaOnline August 2020 Volume 26 I Number 06