Urbanization and the Geoenvironment - Sustainable Practices in Geoenvironmental Engineering - page 233

7.4 Impact Avoidance and Risk Minimization
As cities grow, the problems and stresses created by human-urban activities on the land
environment will escalate. The requirements to satisfy the classical “food, shelter, cloth-
ing, and recreation” needs of the community impose several demands and stresses on the
urban environment and its contiguous regions. To a very large extent, the main challenges
for an urban society are linked to (a) sensible land management, (b) energy utilization-
consumption and management, (c) nonenergy-type resources (food, minerals, building
materials, etc.) consumption and management, (d) waste management, (e) reduction of
contamination to air and water, and (f) water resources management.
7.4.1 Waste Management
7.4.1.1 Contamination Management and Prevention
Waste generation (urban and industrial) is a large problem. New land must be acquired
for classical waste disposal techniques involving landills when older landills become
illed and are decommissioned. Modern requirements for environmentally sensitive waste
disposal and treatment require considerable resources. The essence of these requirements
is embodied in the 4Rs: recycle, reuse, reduce, and recover. Reduction of waste enter-
ing landills is the stated objective of almost, if not all communities and municipalities.
Since 2000, Europeans (Eu-27) on average generate 520 kg of household waste per capita,
which has stabilized despite economic growth until 2008 (European Environment Agency,
Municipal waste generation CSI016/waste 001, published December 2011), Japan also pro-
duces a steady amount (1990 to 2007) at 400 kg per capita, whereas Canada continues to
increase production (777 kg per capita) to twice the amount of Japan. Since 2005, the United
States has begun to decrease its production (Conference Board of Canada, January 2013)
In Switzerland, a family of four generating 100 tonnes of household waste would require
200 m 3 of landill volume. Reduction in land required for waste landills can be obtained
through implementation of the other 3Rs (recycling, reuse, and recover) together with
incineration. Historically, landills used to be located on the outskirts of cites. However,
with the expansion of cities and suburbs in particular, these landills are now part of the
urban-suburban landscape. Although incineration is cleaner and energy eficient and can
substantially reduce the volume of waste, incinerator facilities without beneit of modern
burning systems and eficient scrubber units can emit contaminants into the air and pro-
duce toxic materials and ash that require disposal. Hazardous wastes such as solvents,
oils, medical wastes and highly contaminated soils are often treated by incineration. With
present capabilities and eficiencies in incineration and scrubber systems that can clean
and properly capture contaminants before emission discharge, incinerator are being con-
sidered as the disposal system of choice since they can be located in or near cities. The
system in the city of Vienna, Austria, is an example.
Contamination prevention is a method to reduce damage to the environment for
future generations. Practices such as pesticide addition to lawns, city parks, etc., should
be modiied or eliminated. New methods to control pests should be introduced such as
biological control. Many cities have banned the use of pesticides for private use. The use
of less harmful of hazardous products can reduce contamination through substitution.
A key example where this should have been practiced is the case of CCA-treated wood.
Although it has only recently been banned for use in many countries, wood previously