Planning Integrated WMS for Bangalore |
Bangalore City is in need of an effective solid waste
management system to ensure better human health and safety.
The system needs to be safe for workers and safeguard
public health by preventing the spread of disease. In
addition to these prerequisites, an effective solid waste
manage must be environmentally sustainable and
economically feasible.
It is quite difficult to minimise these 2 variables,
environmental impacts and cost simultaneously. The
balance that needs to be struck is to reduce the overall
environmental impacts of waste management as far as
possible,withinan acceptable level of cost.An economically
and environmentally sustainable solid waste management
system is effective if it follows an integrated approach i.e. it
deals with all type wastes from generation and its disposal.The integrated approach must be based on a
logical hierarchy of actions.
The steps, in order of priority,
which must be taken for Bangalore are as follows:
A reduction in the amount of wastes could be achieved by the following measures:
Studies by lIT, Mumbai, Confederation of Indian
Industries (CII) etc. indicate that nearly 20 percent reduction
in waste generation is possible through simple housekeeping
measure requiring nil or marginal investment. Waste reduction may occur through proper design
of manufacture and packaging of products with minimum
volume of material and longer useful life. Waste reduction
may occur through selective reuse of products and materials.
For example, the Ministry of Environment and Forest,
Government of India has been establishing Waste
Minimisation Circle(WMC)similar to KAIZENof Japan in
large and medium scale industries. Such circles can
introduce a number of practices which can result in the
minimisation of wastes which will ultimately lead to increased
profits for the company.Maximise waste recycling and reuse:
This is the second
best option in IWM. Though recycling of solid wastes is
extensively practiced in Bangalore,the full official recognition
of the need for promotion of recycling is yet to come. It is
only in recent years that the role of this sector has been
receiving some attention. Municipal authorities should
actively support recyclables at source schemes by strengthening
the informal sector, for example by the provision of
sites for sorting of recyclables or perhaps by developing
bonus schemes for the workers in the informal sector.
There are considerable benefits to increasing solid
waste recycling and reuse. Source separation and recycling
of waste reduces the volume of wastes to be disposed. By
promoting recycling as an alternative to existing forms of
waste disposal, the authorities may gain net cost savings.
Authorities may seek competitive bids as the recyclingitself, by itself may be a profitable commercial operation thus
generating them a net income. Also thousands of poor people
support themselves and their families by directly or indirectly
participating in waste collection and recycling. Many
organisations in Bangalore such as Clean Environs, Waste
Wise (Mythri foundation) and Centre for Environmental
Education helps street children and other un~mployed people
to collect wastes from household and gives them a right to
sell it too.Encourage waste processing: Composting and
biogasification :
Organic waste in Bangalore constitutes 75
percent and is therefore amenable to composting and
biogasification. It is a form of source reduction or waste
prevention as the materials are completely diverted from the
disposal facilities and require no managementor transportation.
Diverting such materialsfrom the waste stream frees up
dumping space needed for materials that cannot be
composted.
Currently composting is provided for only 2
markets in Bangalore and this should be extended to other
markets, hotels, restaurants, and households. Composting
is considered viable only if there is a market for compost.
Thus a better understanding of the process, benefits to the
environment and public education can promote the practice
of composting at least in cities where sites and skilled
manpower are available, and marketscan be developed. It is
also essential to provide basic training and education of
workers in technical, health, and safety aspects.
BMP can compost garden and park waste to reduce
wastes for final disposal. Many resident associations in
Bangalore have set up their own composting plants. Waste
Wise Project of Mythri Foundation and the Centre for
Environment Education has set up small scale
vermicomposting plants for providing fertilisers in local parks.
Biogasification is an excellent option in handling
the organic wastes. Once the MSW is segregated into
fermentable and non-fermentable fractions, even at a >90%
efficiency of sorting, MSW becomes amenable for biogas
production.
Biogasification has several advantages such as
net energy output as well as low odour emissions during treatment. Digested material, compost, with or without a
post-composting stage, is safe for disposal as manure. A
study carried out at ASTRA, IISc revealed that plug flow
digestersare very good for biogasification of MSW as it is
anexcellentfeedstock for biogas production and has a very
high gas production (both gas production rate as well as
specific gas production) to warrant viable decentralized
treatment by anaerobic fermentation to biogas. It also
requiresvery little pretreatment.
Promoting the safe disposal of wastes:
Wastes are either
burnt or dumped in open spaces. These practices should be
abolished,as they are deleterious to human health and the
environment. Landfilling occupies the lowest rung in
integrated waste management.However land filling of waste
is a better option than dumping wastes in open spaces.It
relieson containment rather than treatment (for control) of
wastes.The purpose of land filling is to bury or alter the
chemical composition of the wastes so that they do not
pose any threat to the environment or public health.
Land fills are not homogenous and are usually made up of
cells in which a discrete volume of waste is kept isolated
from adjacent waste cells by a suitable barrier. Commonly
used barrier is a layer of natural soil (clay), which restricts
downward or lateral escape of the waste constituents or
leachate.Sanitary landfilling normally has a double liner to
prevent leaching into the groundwater. Appropriate run-off
controls, leachate collection and treatment, liners for
protection of the groundwater(from contaminatedleachate),
biogasrecovery mechanism (due to anaerobic decomposition of
organic wastes landfill gas contains high percentage
of methane),monitoring wells, and appropriate final cover
design constitute integral components of an environmentallysoundsanitary
landfill. Proper and regular monitoring
shouldbe done at landfill sites.