FAQ's

What is a solid waste?
Any solid, be it organic or inorganic material produced by households, commercial, institutional and industrial activities which are of no use and value can be termed as solid waste. The process of consumption of products results in the formation of solid wastes in urban areas and in addition, other processes such as street cleaning, waste-water treatment, etc. also produce solid wastes. These may include glass containers, plastic bottles and other plastic materials, paper, dead and decaying matter of living beings, etc.

What is the need for Solid Waste Management (SWM)?
Most of the cities and towns of India are plagued by the problems related to solid waste. Drains are choking, community bins are overflowing, rivers are dieing and there is filth and garbage littered on the roads. The ever growing population in the Indian cities inevitably adds to the amount of the solid waste being generated in the city. On top of this, there is lack of serious efforts by town/city authorities to tackle this problem of solid waste. In many cities nearly half of solid waste generated remains unattended, giving rise to unsanitary conditions and pollution of land and water bodies. So, as more and more wastes are being generated, very less amount of it is getting recycled by natural or artificial processes. Therefore in such situations, SWM is the most practical solution to this problem.

What are the objectives of SWM?
The two main objectives of SWM are:
i) Waste reduction: the best approach to managing solid waste is to avoid creating it in the first place. Therefore reduce the amount of waste you discard and reuse containers and products instead of throwing them away.
ii) Effective management of solid waste: waste once produced should be effectively handled and recycled/reused in an environmentally sound and economically sustainable manner.

What are the various steps of SWM?
The 5 main steps involved in the process of SWM are:

• Collection: primary collection of wastes from various sources is an important step. Door to door collection, Curbside collection, Block collection, Communal bins are the four methods of collection of wastes from the source of generation which can be households, institutes, industries, etc.
• Transportation: waste collected has to be transported from its source to a place where it can be treated or properly disposed, or otherwise where it can be stored temporarily. Transportation of collected waste from households to the dhalao is known as primary transportation. For this, certain type of vehicles is required such as wheel barrow or light weight rickshaws, etc. Secondary transportation is the transportation of the waste from the community garbage collection center or the dhalao to the disposal site. The size of such secondary vehicle is often larger than the primary vehicle (e.g. trucks with covered roof or compactors).
  The collection and transportation of wastes is the most visible component of the MSW system and simultaneously this is the most neglected component of the system.
• Sorting: is the separation of the various components of the waste from each other so that the different components of the waste can be recycled or treated in an appropriate way. It can be done at various steps viz a viz., household or source level, community bin, dhalao, waste processing site and the sanitary landfill site. The various components like paper, plastic, glass, metals etc. are separated from each other by rag-pickers at these different levels except for the household level.
• Recycling: is the process of conversion of a waste material into a new and valuable product. This is the most important step of SWM as it provides economical benefits also, apart from reducing the amount of waste for disposal. There are various components of waste which can be recycled such as paper, plastics, glass, metals and organic components.
• Treatment and disposal: there are certain components of solid waste which cannot be recycled or are inert. Therefore for such components, either they have to be treated accordingly and finally dispose. Treatment can be done by various processes such as gasification, pyrolysis, supercritical water oxidation, incineration, composting, etc. Finally the waste has to be disposed in the sanitary landfill sites.

What are the various types of solid waste?
We can categorize the various solid wastes into various types but the most general categorization is made on the basis of the source of the waste:

• Household waste: it consists of household wastes such as paper, plastics, metals, organic wastes, etc. It may also include waste from residential and commercial complexes as well as wastes from streets. Eg.- newspaper, cardboards, glass and plastic bottles and containers, aluminium cans, organic wastes such as vegetable residues, spent tea leaves, etc.
• Industrial or hazardous waste: all wastes generated in industries and factories. They are considered hazardous as they contain toxic substances. Coal ash, blast furnace slag, strontium from batteries, reactive chemicals, corrosives such as acids, etc.
• Biomedical or hospital wastes: it consists of waste generated during diagnosis, treatment or immunization of human beings and animals or in research activities done in this process. Some examples are cotton swabs contaminated with blood or body fluids, instruments used during diagnosis or treatment such as syringes, needles, sharps, etc., laboratory wastes and glassware, radioactive wastes used during analytical and diagnosis procedures and chemical wastes.
• Agricultural waste: any waste materials generated during the process of farming and related activities. They are more prominent in semi-rural and rural areas. Animal excreta, crop residues and other vegetable matter, rice husk, bran, bagasse, etc.
• Construction and demolition waste: is generated wherever any construction or demolition activities are going on such as building roads, buildings, sub-ways, etc. These types of waste are usually inert and non-biodegradable materials such as concrete, plaster, wood, metal, plastics, rubble, gritty materials, etc.

What are the harmful effects of mis-management of solid waste?
Few of the harmful effects arising out of the miss-management of solid waste are:

• Organic wastes provide favourable conditions for the survival and growth of microbes and vectors such as flies, mosquitoes all of which lead to outbreak of infectious diseases
• Chemicals and other toxic materials from wastes dumped near water bodies may leach into these water bodies leading to there contamination.
• Such hazardous wastes may also leach into the ground water through the rain water. If such contaminated water is used for drinking or other household purposes, various kinds of diseases and poisoning may be caused.
• Cuts or physical injuries may occur by the sharp objects present in the waste dump.
• Incineration activities may lead to cancers.
• Landfill sites may be contaminated by infectious dust which may lead to eye and respiratory infections.
• Burns and injuries may result from the explosion of methane gas from the landfill sites.
• Plastics are the major cause of concern in urban areas. Unhygienic and unsafe disposal of plastics may lead to accumulation of toxic chemicals which may leach into the soil and underground water.

What are the 3 R's of solid waste management?
The 3 R's of solid waste management are Reuse, Recycle and Reduce. These three R's are ways to reduce the amount of waste generated and prevent the harmful effects of wastes which have been generated.
Reuse means that instead of throwing away a product just after its use is over use it again for the same or maybe another purpose. Instead of discarding a worn out cloth, either mend it and wear again or give it to someone else. Reuse mineral water bottles for storing something. There can be many such examples.
Recycling turns materials that would otherwise become waste into valuable resources. For example, composting organic wastes is a very good example of recycling. Paper and many such items can be recycled into new and valuable products
Reduce requires to minimize the generation of waste materials at the source itself. If less waste is generated, consequently less waste will be required to be disposed off.

Is recycling worthwhile?
Recycling turns materials that would otherwise become waste into valuable resources. It is considered to be one of the best environmental success stories of the late 20th century.
There are several key benefits to recycling. Recycling:

• Reduces the need for landfilling and incineration.
• Saves energy and prevents pollution.
• Decreases emissions of greenhouse gases that contribute to global climate change.
• Conserves natural resources especially non-renewable ones such as aluminium and other metals.
• Helps sustain the environment for future generations by conserving the resources for them.
• Provides a source of livelihood for innumerable people engaged in recovering of recyclable materials (rag pickers and "kabadiwallahs") and those engaged in recycling.

How does recycling save energy?
Harvesting, extracting, and processing the raw materials used to manufacture new products is an energy-intensive activity. Huge amount of energy would be saved if these processes are either reduced or by-passed. For example- recycling aluminium cans would save almost 95% of energy that would be required in manufacturing the same amount from the ore-bauxite. Similarly, recycling of paper not only leads to reduction on the demand for cutting of trees but also saves energy. The amount of energy saved differs by material, but almost all recycling processes achieve significant energy savings compared to production using the raw materials (virgin materials).

What effects do waste prevention and recycling have on global warming?
Waste prevention and recycling also have an impact on global warming and climate change. The manufacture, distribution, and use of products-as well as management of the resulting waste-all result in greenhouse gas emissions. Therefore reducing waste is a very good tool for reducing greenhouse gas as it:

• Recycling saves energy. When people reuse goods or when products are made with less material, less energy is needed to extract, transport, and process raw materials and to manufacture products. When energy demand decreases, fewer fossil fuels are burned and less carbon dioxide is emitted into the atmosphere.
• Reduce greenhouse gas emissions from waste combustion. Recycling and waste prevention leads to less amount of waste being produced. Thus less amount of waste would be required for incineration and thus fewer amounts of greenhouse and other harmful gases would be produced.
• Reduce methane emissions from landfills. Waste prevention and recycling (including composting) reduce the amount of organic waste being dumped into landfills leading to less formation of methane gas which is also a greenhouse gas.
• Prevents deforestation. Waste prevention and recycling paper leads to less cutting down of trees which prevent the reduction in the forest area worldwide. As trees absorb carbon dioxide from the atmosphere and store it in wood in a process called "carbon sequestration", therefore it's important to recycle paper so that more and more of greenhouse gases are absorbed.

How can we reduce generation of waste?
Reducing the amount of waste being generated at the source itself is the most preferred method of waste management. We can ensure reduction of waste by:

• Purchasing durable, long-lasting goods
• Seeking products and packaging that are as free of toxics and biodegradable as possible
• Redesigning products and manufacturing techniques to use fewer raw materials in production, have a longer life, or such that the products are used again after its original use.

What are the various ways of disposing the waste materials?
The various ways of disposing and treatment of waste materials are:

• Dumping in landfills: When large amount of wastes are generated in a city or an area, all the wastes are dumped in an open empty land and covered with soil. This land is then compressed with land moving device. This is the most common method of waste disposal all over the world as it is the easiest way of getting rid of the wastes. However this is not the best way for disposing off the wastes as this practice leads to many health and environmental problems. Therefore scientific or sanitary landfills are better options where the wastes are disposed in a scientific manner and having provisions for pollution control, etc.
• Incineration plants: incineration is the process of burning the waste in a large furnace. It is usually done for disposing non-recyclable materials which are left after segregation. This method is also not safe as harmful gases are generated which can also be carcinogenic. Ash is also produced whose disposal is another environmental issue. Therefore in India this process is not very common except in the hospitals and some industries.
• Composting: it is done to recycle the organic wastes. Composting involves the biological breakdown of degradable components into humus with the help of micro-organisms such as fungi and bacteria and also using earthworms (vermi-composting)
• Gasification technique: When the waste material is partially burnt at a temperature of 650 to 850 oC (in a partially oxygen-deficient environment) low heat content fuel gases are produced. This is called gasification. These fuel gases can be burned off or can be tapped and used later on for burning. This is a very promising technique as there is considerably less emission of harmful and greenhouse gases and other pollutants than the incineration technique.

How come landfills are not the safe way of waste disposal?
The current method of disposing waste in landfills in many countries is not environmentally friendly as it is mostly done in an uncontrolled manner. However it is still the most common method. In many instances landfill sites are not chosen properly in terms of geophysical, topography, hydrology, soil properties and climate. Even when a site has been selected after proper considerations, there is no guarantee that surface run-off or leaching of harmful chemicals and materials wouldn't occur. To reduce this threat, landfill sites have been lined with plastic materials and other materials to prevent leaching into the groundwater. Another risk posed by the landfill sites is the release of harmful gases like methane. Apart from such problems they are also major breeding grounds of all kinds of disease-causing organisms such as mosquitoes and flies.

What is sanitary landfill?
The current method of disposal of waste in landfills is not in a controlled manner at all. It is just a huge open dump where wastes are dumped daily in an unscientific way which leads to various environmental and health issues such as leaching of harmful substances in underground water or release of harmful gases like methane and communicable diseases like malaria, etc. therefore, as per the Municipal Solid Wastes (Management and Handling) Rules 1999 the landfills should be built according to proper guidelines outlined in the rules. A sanitary or scientific landfill has provisions for leachate management and the possible collection of landfill gas like methane and its potential use as an energy source. To prevent seepage of leachates into the ground, the base and sides of the landfill are lined with materials like clay, PVC or asphalt, in addition to this there is also a leachate collection and treatment system which collects and extracts leachate from within and from the base of the landfill and treats to meet the regulatory requirements. The final cover of the landfill enhances surface drainage, prevents infiltration of water and supports surface vegetation. Finally the SFL should also have a environmental monitoring system which would periodically collect and analyse air, surface water, soil and ground water samples around the landfill site.

What is composting?
Composting is the controlled biological decomposition of organic matter, such as food and garden wastes, into a dark-coloured porous substance called compost. Composting is a natural way of recycling organic waste into the compost which can be used in vegetable and flower gardens, landscaping, and many other applications. This process comprises of two main steps: mineralization or release of inorganic components from organic matter and humification or the formation of humus. The most common composting methods are:

• Backyard or Onsite Composting : can be done at a household level.
• Vermicomposting: make use of earthworms rather than microorganisms.
• Aerated (Turned) Windrow Composting : done when large amounts of organic wastes have to be recycled.
• In-vessel Composting : composting done in special vessels called in-vessel composter.

What materials can be composted and which ones cannot be composted?
Following is the list of items which can be composted:

• Animal Manure.
• Cotton Rags.
• Dryer and vacuum cleaner lint.
• Eggshells.
• Fireplace ashes.
• Fruits and vegetables.
• Grass clippings.
• Hay and Straw.
• Houseplants.
• Leaves
• Nut shells
• Sawdust
• Shredded newspaper
• Tea bags
• Wood chips

And following is the list of items which should not be composted:

• Coal or charcoal ash
• Dairy products (e.g., butter, egg yolks, milk, sour cream, yogurt)
• Meat or fish bones and scraps
• Pet wastes (e.g., dog or cat feces, soiled cat litter)
• Fats, grease, lard, or oils
• Yard trimmings treated with chemical pesticides
• Diseased or insect-ridden plants.

What are the environmental benefits of composting?
The end product of composting called compost can be used as manure for enriching the soil. This compost has many environmental benefits:

• It has the ability to regenerate poor soils. The composting process encourages the production of beneficial micro-organisms (mainly bacteria and fungi) which in turn break down organic matter to create humus which increases the nutrient content in soils and helps soils retain moisture.
• It has been found that compost can suppress certain plant diseases and pests thus reducing the use of pesticides.
• Composting process has been found to absorb volatile organic compounds present in the air
• Compost can bind heavy metals and prevent them from migrating to water resources or being absorbed by plants.
• Prevents soil erosion.
• Cost-effectively remediate soils contaminated by hazardous waste.
• Using compost can reduce the need for water, fertilizers, and pesticides. It serves as a marketable commodity and is a low-cost alternative to standard landfill cover and artificial soil amendments.
• Composting organic matter reduces the load on the landfills, therefore preventing the release of harmful gases and leachates.

What is the role of moisture content and temperature in the composting process?
In the process of composting there are certain aspects which play an important role. Among them are moisture content and temperature. Water is an important element that helps transports substances within the compost pile and makes the nutrients in organic material accessible to the microbes. Microorganisms also require an optimum temperature range to carry on the process of composting. Certain temperatures promote rapid composting and destroy pathogens and weed seeds. Microbial activity can raise the temperature of the pile's core to at least 140 °F otherwise anaerobic conditions might set in leading to decrease in rate of composting. Therefore adequate moisture and optimum temperature should be maintained in order to increase the rate of composting.

What is role of oxygen in composting process?
The rate of decomposition is hastened by aeration otherwise anaerobic conditions might set in leading to decrease in rate of composting. Turning the pile, placing the pile on a series of pipes, or including bulky agents such as wood chips and shredded newspaper all help aerate the pile. However too much of oxygen might lead to drying up and decrease in composting process.

What is vermicomposting?
Vermicomposting is also composting but using earthworms alongwith the . These earthworms can easily move through the various layers of soil and can ingest anything releasing special particles called castings which are high in organic content. Proper temperature and moisture content has to be maintained as earthworms are extremely temperature-sensitive. One pound of mature worms (approximately 800-1,000 worms) can eat up to half a pound of organic material per day. It typically takes three to four months for these worms to produce harvestable castings.

How can I compost?
Composting is easy. However it requires regular mixing or turning and watering. You can make your own compost pit by following this process:
1. Make a pit of around half meter wide, one meter long, one meter deep.
2. Fill it with grass, dry leaves, used tea leaves and other decomposable matter.
3. Put all the organic waste into it.
4. Cover it with the dry leaves and grass daily.
5. Water it twice or thrice in a week to keep it wet
6. Mix and reshuffle the waste once or twice within 15 days.
7. You will get the compost in 3-4 months time.

Why burning dry leaves and other wastes in public is prohibited?
Burning of dry leaves and other wastes in public is prohibited because it pollutes the air and can lead to uncontrolled fires. Smoke produced can lead to breathing difficulties for people who suffer from asthma, emphysema, chronic bronchitis, or allergies.