Municipal Solid Waste (MSW) collection
| Efficiency in collecting solid waste & segregating it decides how well solid waste is managed.Collection includes not
| only the gathering of solid waste, But also the transport of these Materials, after collection, to the Location where the collection vehicle is emptied. This location may be a material processing Facility, a transfer station or a landfill disposal site.
Now a days it is one of the Most important issue in municipal Administration, particularly in Metro cites. Huge generation of MSW is one of the reasons behind the administrative difficulty. As per the Maharashtra pollution Control Board (MPCB) report, estimate total Solid waste generated in 22 Municipal Corporation is 13889 MT/D & solid waste generated in 231 Municipal Councils is 2727.29 MT/D, so one can image the task of collecting the generated municipal Solid waste. Major part of this MSW is Non point source, so collecting it becomes difficult.
Composition of MSW in a Typical Indian City
The general composition of solid waste being generated from the cities of India is 40% Food & Garden waste, 5% glass & Ceramics, 3% Metal, 15% inert, 4% Plastic/ Rubber, 6 % Textile, 27 % Paper.
Total Organic Fraction - 40%, Combustible Fraction - 37%, Recyclables - 8%, Inert - 15%
|Source: CPHEEO Manual on MSW, 2005
According to State of Environment Report, 2009 about 90 per cent of the municipal solid waste generated in Mumbai and Chennai is being collected. However, in Delhi there is no adequate system of collection as only 77 per cent of the municipal solid waste generated is collected.
Functional elements of MSW collection
Collection of MSW broadly involves following functional elements-
Stage I: Collection from Non point Source:
This stage includes door-to-door collection of waste. Most collection is done by garbage
collectors who are employees or firms under contract to the government. Garbage collectors
employed by local governing bodies manually collect the waste generated at the household level and
dump it in the community bins at specified street corners. Municipality is not responsible for door to
door collection of waste from houses, offices, small shops and small markets. Here people are required
to deposit their wastes in communal containers/ community bins (stationary or haul types), from
which it is collected by municipal crews. The vehicle used in this stage for collection, is small and simple
& varies from place to place. It may be two-wheeled cart pulled by an individual or bell ringing vehicles (ghanta gadi).
Stage II: Collection from Point Source:
Waste collected from non point source deposited to definite point sources namely communal
bins. Communal bins are placed near markets, in apartment complexes, and in other appropriate
locations. Shopping complex, hotels, public places like gardens, religious places are other definite point sources. Vehicles collects large amount of waste from these point sources and then transported to
transfer stations and disposal sites by vehicles. Manually or mechanically loaded compactors are often
used in this stage. Placing communal bins at appropriate locations for deposit and storage of waste is
important to manage waste properly. For better MSW management garbage should be lifted frequently
from these point sources. Frequency in lifting garbage from these points really matters otherwise
garbage pile up & create other problems. It is challenging task particularly in metros. In Mumbai 983
Municipal and Private Vehicles used for collection of waste making 1396 number of trips each day. (2009,BMC website)
Stage III: Transportation to Disposal sites:
Transfer refers to the movement of waste or materials from collection points to disposal sites.
Transportation of waste from collection point to disposal sites is carried out by using different types of
vehicles depending on the distances to be covered by them. Larger vehicles carry the waste from the
collection points to the disposal sites. Comparatively small vehicles discharge waste at transfer stations
where the wastes are loaded into larger vehicles for transportation to the disposal sites. In metro cities
transfer stations located at different places to support intermediate transfer of waste from the
surrounding areas upto the dumping grounds. Transfer stations are centralized facilities where waste is
unloaded from smaller collection vehicles and re-loaded into larger vehicles (including in some
instances barges or railroads) for transport to a disposal or processing site. The transportation of
garbage from the transfer stations is done generally using Trailers and Bulk Refuse Carriers. In large
cities, open flatbed trucks, covered trucks, and some compactors are in use, whereas in smaller cities
tractor-trailers, tricycles and animal carts are common. Study shows that in metros like Mumbai, around
60 per cent of waste is transported through stationary compactors, mobile compactors and closed
tempos; 10 per cent is through partially open dumpers whereas 20 per cent is through tarpaulincovered
vehicles, which includes silt and debris.
Collection & transportation of MSW can be schematically shown as-