Solid Waste
SOLID WASTE
What is solid waste?
From ancient time, waste has remained an inseparable part of the human society. The rapid population growth, growing urbanisation and proliferation of slums are all contributing to the generation of an ever increasing volume of garbage. The increasing pile of garbage has created health hazard and environmental problem.
Types of solid waste:
· Solid waste can be classified into different types depending on their source:
· Household waste is generally classified as municipal waste,
· Industrial waste as hazardous waste, and
· Biomedical waste or hospital waste as infectious waste.
Domestic Waste:
Municipal solid waste:
Municipal solid waste consists of household waste, construction and demolition debris, sanitation residue, and waste from streets. This garbage is generated mainly from residential and commercial complexes. With rising urbanization and change in lifestyle and food habits, the amount of municipal solid waste has been increasing rapidly and its composition changing.
Bio-Medical Waste:
Hospital waste is generated during the diagnosis, treatment, or immunization of human beings or animals or in research activities in these fields or in the production or testing of biologicals. It may include wastes like sharps, soiled waste, disposables, anatomical waste, cultures, discarded medicines, chemical wastes, etc. These are in the form of disposable syringes, swabs, bandages, body fluids, human excreta, etc. This waste is highly infectious and can be a serious threat to human health if not managed in a scientific and discriminate manner.
During 1993 - 94, a survey was carried out in Guwahati, being the gateway of North- East India where attraction of lot of people to different parts of the country creates generation of wastes of different categories from household to commercial to study the aspects of Municipal solid waste management (MSW) and the associated problems along with the generation pattern, quality and quantity. This study on MSW was made for a period of one year covering three seasons - winter, pre-monsoon and monsoon.
Storage of waste in community bins is found to be unsatisfactory in the whole city as people are often reluctant to walk to the community bins and therefore dump the waste on side walks, streets or open drains. This creates unhygienic condition in the locality and also creates problems for the Municipality Office to collect the waste for transportation. Lack of proper drainage facility and the large scale built up areas within the city leading to substantial increase in waste generation and flow of water and reduction in low lying areas within and around the city affecting the holding capacity or dumping of the drainage flow. In Guwahati, there is no mechanised recovery and recycling of solid waste, the manual recovery by individual scavengers at the city bins are carried out as well as at the dumping sites also.
Hospital waste is not segregated and in the study it is found that three hospitals viz., Wintrobe, Down Town and Neurological Research Centre in the city, has adopted incinerator for disposal of hospital waste. In Down Town Hospital, the incinerator is used for providing hot water to the bathrooms during the morning and evening hours. Water collected in storage tanks is passed through the incinerator through pipes, which are connected, to the bathroom. The incinerator ash produced is disposed in a small dumping ground near Super Market. The kind of wastes fed into the incinerators are used cotton, bandages, disposable syringes, papers and other items including saline pipes. The incinerator in Wintrobe Hospital is not used for any other purpose other than burning the hospital waste. But there was no specific arrangement for disposing off the ash, as found in the survey.
Hazardous Waste:
Industrial and hospital waste is considered hazardous as they may contain toxic substances. Certain types of household waste are also hazardous. Hazardous wastes could be highly toxic to humans, animals, and plants; are corrosive, highly inflammable, or explosive; and react when exposed to certain things e.g. gases. Household wastes that can be categorized as hazardous waste include old batteries, shoe polish, paint tins, old medicines, and medicine bottles. Hospital waste contaminated by chemicals used in hospitals is considered hazardous. These chemicals include formaldehyde and phenols, which are used as disinfectants, and mercury, which is used in thermometers or equipment that measure blood pressure.
In the industrial sector, the major generators of hazardous waste are the metal, chemical, paper, pesticide, dye, refining, and rubber goods industries. Direct exposure to chemicals in hazardous waste such as mercury and cyanide can be fatal.
Management of Municipal Solid Waste:
The urban local bodies in the state are yet to take necessary steps for proper Management of MSW in the field of collection, segregation, storage, transportation, processing and disposal of MSW.
Collection of MSW:
In Assam, door to door collection of MSW has been taken up by Guwahati Municipal Corporation alongwith Silchar, Umrangshu, Maibang, Halflong, Badarpur, Karimganj and Sivasagarh town municipal bodies. In other parts, old practice is continued i.e. MSW collected from road side bins provided at different locations by Practically no proper segregation of waste is practiced in the State of Assam Truck, Tractor, Thellas and taken into the dumping ground.
Segregation of MSW:
Practically no proper segregation of waste is practiced in the State of Assam
Storage of MSW:
Age old practices are followed by most of the local bodies for storage of waste. Dustbins are provided in some locations and the wastes are collected in an interval of 2 – 3 days. On Guwahati city colour coded bins are provided at some selected area. In Pachim Boragaon area. Guwahati, a temporary storage facility has been set up by Guwahati Municipal Corporation
Transportation of MSW:
For transportation of MSW generally tractor, truck, tipper, hand cart etc. are used in the State of Assam.
Processing of MSW:
For processing of MSW there is no process plant. One MSW processing unit is coming up in Dibrugarh district of Assam.
Disposal of MSW:
Except Guwahati city, all other local bodies are utilizing low lying areas for disposal of MSW
Specification for Land Fill Sites:
Most of the local bodies do not have any proper, scientific, well developed land fill sites. Identification and allotment of land for land fill sites are recently practiced in some parts of the state. Necessary land fill site for 100TPD MSW facility in Dibrugarh town have been selected.
Standards for Composting Treated, Leachate and Incineration:
Except Guwahati city there is no any composting or incineration facilities are available in the State of Assam.
Municipal Solid Waste Rule 2000
Source: Guwahati Municipal Corporation
Pollution Control Board, Assam