Environmentally Sound Technologies
Environmentally Sound Technologies are technologies that help
protect the quality of the environment. It may be argued that technologies used
to manage wastewater and stormwater are inherently environmental technologies,
because without these technologies the pollutants in wastewater and stormwater
will negatively affect the environment. Some of these technologies may utilise
less energy than others, produce less air pollution or hazardous sludge, or are
more suited to wastewater and sludge reuse. Hence some of these technologies are
more sustainable. The application of a technology is dependent on local physical
factors including land availability, its topography, climate, soil, availability
of energy and existing land uses. Sound technology practice is therefore
dependent on being able to fit the technology to the local conditions.
Sound practice is also dependent on the context of the local
community where the technology is to be applied. Long term sustainability is a
function of community resources (funds, skills) to afford the technology and its
willingness to pay for the technology and its operation. Sound practices are
therefore practices that fit into the environmental, economic, social, cultural
and institutional setting of the community.
In this document, wastewater and stormwater characteristics are
described to set the context for technologies that need to be used to manage the
pollutants they contain. The description is also meant to indicate the resources
that are contained in human excreta, and therefore its potential for reuse.
Technologies for collection, treatment, reuse and disposal are then described,
so that options for different local environmental, economic and social contexts
can be evaluated. The description is not meant to be exhaustive, but to enable
the scientific basis of the technologies to be understood.