Urbanization and the Geoenvironment - Sustainable Practices in Geoenvironmental Engineering - page 241

Roof runoff

Optional collection tank

Evapotranspiration

Overflow for seepage

Return water for recycling to
toilets, lawn watering, etc.

Filter pit and
groundwater cistern

Groundwater To surface water

FIGURE 7.9
Recycling of roof and wastewater to replenish groundwater and provide nonpotable water for housing.
(Adapted from information in König, K.W., Rainwater in cities: A note on ecology and practice. In T. Inoguchi,
E. Newman, G. Paoletto (eds.), Cities and the Environment: New Approaches for Eco-Societies , United Nations
University Press, Tokyo, pp. 203-215, 1999.)

7.4.3 Reduction in Energy Usage, Ozone Depletion, and Greenhouse Gases

As the burning of wood, coal, petroleum, and natural gas leads to substantial production
of greenhouse gases and promotion of acid rain, it is obvious that reduction in the use of
these energy sources is essential—as a step to fulilling the requirements of the 1997 Kyoto
Protocol. Although many different other steps are needed to meet the requirements, and
whereas this is an essential step in the right direction, it is recognized that combustion
of fossil fuels is not a sustainable practice. Other sources of energy such as solar, wind,
geothermal, hydrothermal, and hydroelectricity produce less greenhouse gases than the
above-mentioned fuels. In the case of acid rain, the choice of fuels with lower sulfur and
nitrogen oxide contents can also minimize acid fallout and damage to soil, water, fauna,
and humans. Nuclear energy is a clean energy. However, the problems of spent fuel rods
and other radioactive waste materials are substantial and have yet to be fully resolved. A
recounting of the repository disposal of high level nuclear wastes and the technological
tools for managing such wastes can be found in Pusch and Yong (2005) and Yong et al.
(2010). Biogas from waste dumps should be recovered and used for heating purposes. For
example, the St. Michel Environmental Complex, in Montreal, Canada, recovers, at the
landill, approximately 20 MW of electricity, which is enough to power 12,000 homes.