Environmental Engineering Reference
In-Depth Information
99% of spending on stormwater management went to systems that have pipes or tunnels
to move stormwater runoff away from human development and into local waterways or
to central processing plants. Regulations and incentives have recently and somewhat radi-
cally changed in some locations where oficials are attempting to restore natural systems, a
process in the design community broadly called “biomimicry.” Municipalities, large cam-
pus locations, and developers are now seeking runoff control for quality as well as quan-
tity upgradient, but are inding the need to deal with industrial chemicals a challenge.
These cultural forces and regulations can be seen as marketplace “sticks.” At the same
time, many architects are inding their design bonus payments attached to “carrots” in the
form of LEED certiications. LEED certiication incorporates green stormwater manage-
ment as a critical aspect of building design.
Domestically, the US market for relieving nonpoint source pollution and stormwater vol-
ume is estimated to be $6 billion annually. The Seattle area alone has announced an initia-
tive to build 12,000 green stormwater sites over 5 years with a goal to reduce urban runoff
by 16,000,000 gallons annually. Boston, Philadelphia, and the Chesapeake Watershed Joint
Management Group completed scoping documents and announced targets for this market
in 2014, which is on scale with the Seattle initiative.
Internationally, especially in areas with lack of access to easy freshwater, the carrot of the
marketplace is in capturing and safely harvesting urban runoff for human usage. Areas of
the Mideast and West Africa have deep and acute needs for stormwater harvesting, while
increasingly toxic urbanized environments and the extraction industry make the chal-
lenge of cleaning the water more dificult.
33.5 Osorb and the Need for Innovations in Stormwater Technology
Rain gardens and bioswales (landscape elements designed to remove silt and pollution
from surface runoff water) are very effective at reducing runoff volumes, but have gener-
ally failed to improve runoff quality from affected urban locations. They are generally use-
ful only as small systems capturing stormwater from single residential locations or small
groups of residential properties and make up far less than 1% of the total amount spent on
stormwater management in the United States.
Osorb stormwater systems incorporate blends of Osorb nanomaterials and bioretention
soils to capture and reduce organic pollutants. Osorb is a highly ordered and mechanically
functionalized silica material capable of hinge-like unfolding of individual and function-
alized nanopores. The material has been further engineered to include embedded nano-
metals and micrometals inside the Osorb glass, which causes chemical species captured
by the Osorb to undergo a chemical reduction (Table 33.1).
The challenge with all the species of pollutants in Table 33.1 is that they are commonly
found on hard, impervious surfaces in urban or industrial settings. These chemicals are
persistent, bioactive, and easily entrained in stormwater runoff. Previous systems could
capture the stormwater but frequently suffered from mass plant die-offs or soil biological
collapse. Often the pollutants would pass into the water table to create further problems in
groundwater and well water, as well as downgradient reemergence.
Adding nanoglass allows the stormwater system to address both water volume and qual-
ity in an effective and energy-eficient manner. Furthermore, most stormwater processed
