ENVIRONMENTAL IMPACT ASSESSMENT ON
SOLID WASTE MANAGEMANT
ABSTRACT
Due to increase in population, the Indian environment has undergone rapid changes. Uncontrolled growth of population is tremendous for which an innovative disposal technique is essential. The composition of municipal solid waste typically in India has about 40-45% organics and about 40% construction waste. The organic waste needs to be segregated and vermi composted at site. This will solve 40% of the problem. Plastic, paper, glass and metal should be recycled and not wasted in landfills.
Nowadays here is no system of segregation of organic, inorganic and recyclable waste at household level.The term solid waste usually refers to waste that is solid including semi-liquid or wet waste with insufficient moisture content needed to make it flow.
In year time, the disposal of human and other waste does not pose a significant problem for the reason that population was small and amount of land available for the assimilation of waste was large.
Now due to rapid population growth and economical development in the country, solid waste disposal has become a major environmental issue in India.
Being comparatively cheaper, Open Dumping method is extensively used in our country. When solid waste is dumped on open ground, it causes the following Environmental problems.
Ground water contamination, through seepage of leachate into the ground.
Unmanaged solid wastes openly dumped on the land generate liquid and gaseous emissions that pollute the environment.
It represents the breeding ground for disease-bearing animals and micro organisms.
Methane and carbon-di-oxide gases are produced during bio-degradation of waste.
INTRODUCTION
GENERAL
Preserving a good natural environment is essential for a good health and quality of life. However, at present, the environment is damaged all around the world by several main factors, such as global warming gases emissions, excessive resources extraction or persistent organic pollutants release. Any material that is thrown away or discarded as unwanted and useless is considered as Solid Waste. Municipal Solid Waste (MSW) is being produced since earth’s evolution. During the early period, MSW was conveniently disposed off in low lying areas with large open land space. The population growth is led to increase in solid waste generation. The problem of waste disposal and its adverse impact on the environment is recently diagnosed.
Waste is one of them. Particularly, MSW creates special concern among the general public due to its close relationship with the daily life of the lay person. Management of urban solid waste is the major challenge for engineers and town planners. Huge volumes of solid wastes are generated everyday and need to be collected, transported and finally disposed off. Unhygienic and obsolete method adopted for the disposal of solid waste posses a serious health concern.
Municipal Solid Waste in India is generally littered on roadsides and disposed in an unscientific manner without considering the importance of garbage. The waste is dumped in the outskirts of the cities in low lying areas with no compliance of regulations. The dumped waste contains organic, inorganic and inert material like debris in mixed form.
Municipal solid waste is a problem in most cities due to rapid urbanization, unplanned growth, nil segregation at source and unorganized collection of waste. The two role players are the municipalities and rag pickers which have no coordination amongst them. The composition of municipal solid waste typically is India has about 40-45% organics and about 40% construction waste. The organic waste needs to be segregated and vermin composted at site. This will solve 40% of the problem. Plastic, paper, glass and metal should be recycled and not wasted in landfills. Construction and miscellaneous waste only needs land filling. Without appropriate segregation and management, municipal solid waste can become a severe threat to the communities living nearby and the environment.
Solid wastes have potential for causing serious adverse impact on the environment. Following are the examples
Ground water contamination
Land pollution
Air quality deterioration.
Environmental impacts of poorly managed solid wastes have been studied all over the world. It is now well known that a large number of disease vectors and water borne diseases spread due to poor waste collection and disposal practices.
Indian cities / towns generate on an average 300 – 400 gm per capita per day. The waste generation of corporation is 643 MT / day.
GENERAL COMPOSITION OF THE MUNICIPAL SOLID WASTE
S.NO | MATERIALS | PERCENTAGE |
1 | Bio-degradable matter | 50% |
2 | Glass | 4% |
3 | Plastics | 3% |
4 | Paper | 5% |
5 | Metals | 1% |
6 | Leather & rubber | 1% |
7 | Rags | 5% |
8 | Household hazardous | 1% |
9 | Inert materials | 30% |
SOURCES OF SOLID WASTE
There are various sources of Solid Waste. They are as follows,
RESIDENTIAL WASTE
This includes single family and multi family houses, low, medium and high rise apartments, etc. this consists of food waste, rubbish, ashes, special waste. It is purely domestic waste.
COMMERCIAL WASTE
This includes wastes from restaurants, markets, stores, hotels, institutions, office, workshops, etc.,
INDUSTRIAL WASTE
This is from construction, fabrication, light and heavy manufacturing, chemical plants, mining, power plants, deduction, etc.,
OPEN AREAS WASTE
The waste is from parks, vacant lands, play grounds, beaches, etc.,
TREATMENT WASTE
This kind of waste is liberated from water, wastewater and industrial treatment processes, etc.,
AGRICULTURAL WASTE
This is from field and row crops, orchards, diaries, feedlots, farms, etc.,
TYPES OF SOLID WASTE
There are various types of Solid Wastes. They are as follows,
GARBAGE
Food wastes are the animal, fruit or vegetable residues resulting from handling, preparation, cooking and eating of foods.
RUBBISH
This consists of combustible and non-combustible Solid Wastes of households, institutions, commercial activities, etc., excluding food wastes or other highly pursuable materials.
E.g., Combustible – paper, cardboard, leather, etc.,
Non – combustible – aluminum cans, tin cans, glass, etc..,
ASHES AND RESIDUES
Materials remaining from the burning of wood, coal, coke and other combustible wastes are categorized as ashes and residues.
DEMOLITION AND CONSTRUCTION WASTES
Wastes from buildings and other structures are classified as demolition wastes. Wastes from the construction, remodeling and repairing of individual residences, commercial buildings and other structures are classified as construction waste.
SPECIAL WASTES
Wastes such as street sweepings, roadside litter, catch basin debris, dead animals and abandoned vehicles are classified as special wastes.
HAZARDOUS WASTES
Chemical, biological, flammable, explosives or radioactive waste that are harmful to human, plant or animal life belongs are classified as hazardous wastes.
DISPOSAL OF SOLID WASTE
Open dumping
Land Fills
Composting
Recycling
Incineration
OPEN DUMPING:
Open dumping of solid waste is done in low-lying areas and outskirts of the towns and cities .Being comparatively cheaper, this method of disposal is extensively used in India. Open dumping requires large land areas, which further leads to the problem of land shortage for human habitation. It can be done in two ways,
Dumping on land
Dumping in water
Dumping on land was a simple task to haul solid wastes to the edge of town and dump them there; open dumps became a common method of disposal for urban communities. Open dumps also attracted flies and rats that spread diseases. This haphazard disposal became a matter of great concern to public health authorities who were given responsibility for the control of solid wastes.
Dumping in water was used by coastal areas, in spite of that it was not favored because the pollution consequences were well recognized.
OPEN DUMPING OF SOLID WASTE
LANDFILL:
The term sanitary landfill means an operation in which the wastes to be disposed off are compacted and covered with the layer of soil at the end of each days operation. Solid wastes are placed in alternate layers of 80cm thick refuse covered with selected earth fill of 20cm thickness. After two or three years, solid waste volume shrinks by 25-30% and the land is used for various purposes. Mixed refuse can be disposed without any segregation of constituents. Greater care is required for the site selection. Even though it is simple and economical method, leaching of waste water chemicals into the adjoining areas leads to solid and water pollution. Also this results in bad odour and thereby affects the human health.
COMPOSTING:
Composting is the method in which organic matter in the solid waste is decomposed aerobically or anaerobically and converted into humus and stable mineral compounds. In this process bulk organic waste is converted into fertilizing manure by biological action. Alternate layers of refuse 30cm thick and animal dung 5-6cm thick are filled in 1m deep trenches of size 10m x 3m. Finally 5cm thick earth layer fills the top level, which prevents access to insects, loss of moisture content and public nuisance. In a period of 3-4 months manure is ready for use. It is very time consuming and can not handle the large volumes required by cities.
INCINERATION:
Burning of combustible refuse is the safest process of disposal. The major advantage of the incineration process is that it can be used o reduce the original volume of combustible solid wastes by 80-90%.The remaining 10-20% is a residue of black ash which is considered hazardous by most EPA's (Environmental Protection Agencies) and must be disposed of in sanitary landfills. Incinerators can be located at different parts of the town, to reduce the cost of transportation of the refuse. Some incinerator needs additional fuel or proper air supply to maintain high temperature in the burning place. Hospital waste may be safely disposed by this process. The cost of this maintenance as well as the smoke and other objectionable odors and chemicals that emanate from incineration causes resistance by the local population and is highly undesirable.
RECYCLING:
Recycling is one of the most economical methods of controlling pollution seems to be recycling arrangement, ie one in which the pollutants are, by and large, processed at the place of their generation itself and converted into products which could be used there or as raw material for more useful products. Recycling is a much abused term, generally taken to mean getting something back from waste. Eg., News paper recovery by de-inking followed by repulping to make more news print. Recycling falls into three main categories,
- Re-use
Direct recycling
Indirect
OBJECTIVES OF THE STUDY
To determine the solid waste dump areas around the Coimbatore city.
To assess ground water characteristics around the solid waste dump yard.
To compare the quality of ground water with standards.
To determine the condition of water around dump yard.
EFFECTS OF OPEN DUMPING
Disorganized way of dumping of waste leads to formation of secondary pollutants like H2S, Mercaptan and other Hydrosulfurous gaseous pollutants by reacting with
Bacteria present in the waste in the presence of moisture and temperature since there is no engineering concept to collect such gases in proper manner, these are emitted all over the ground in a haphazard manner and this phenomenon of gas emissions is more significant in summer. During monsoon, it gets settled with precipitation (rain) and the effect is not very significant.
IMPACTS FROM DUMPS
A dump will impact its surrounding environment by:
Its presence (area need, visual impact, social impact)
Transportation of waste (noise and air)
Waste attracts animals (vermin, insects)
Waste emits landfill gas (odour, fires, global warming)
Waste emits dust and other materials (plastic)
Waste emits pollutant water impacting groundwater (drinking water problem)
LEACHATES
Leachate is a toxic liquid that seeps through solid waste in a land fill.
This process extracts soluble dissolved and suspended materials from the waste.
It contains bacteria, toxic substances, heavy metals, etc.,
Methane and carbon-di-oxide gases are produced during bio-degradation of waste.
In towns where bio-medical or hazardous waste (for instance batteries, bulbs, and thermometers) mixes with the municipal waste stream, the leachate can cause serious health and environmental problems.
CONTAMINATION OF GROUNDWATER
IMPACTS ON SOLID WASTE
- Water pollution:
Surface and ground water bodies can get contaminated by the leachate released from the dump site; portable ground water may become toxic.
Soil pollution:
Toxic substances released into the soil are absorbed by the surrounding vegetation and move into the food chain.
Air pollution:
When wastes decomposes at dump sites, methane gas is released, which is inflammable and can result in explosions or dump fires.
Global warming:
Methane released from dump sites is one of the main contributors to global warming.
Sources of diseases:
Dump sites breed flies, rodents and pests which carry diseases into the surrounding population.
GROUNDWATER
Groundwater is a gift of nature. It is a precious and the most widely distributed resources of the earth. At present nearly one fifth of all water used in the world is obtained from ground water resources.
Groundwater is an important source of water supply through out the world. It is a source of water for wells and springs. Groundwater acts as a reservoir by virtue of large pore space in earth materials as a conduit that transport water over long distances and as a mechanical filter which improves water quality by removing suspended solids and bacterial contamination.
GROUNDWATER POLLUTION
Groundwater pollution may be defined as the artificially induced degradation of natural groundwater quality.
Pollution can impair the use of water and can create hazards to public health through toxicity or the spread of diseases. The subsurface water is difficult to detect and control.
Human activities are constantly adding industrial, domestic and agricultural wastes to ground water reservoirs at an alarming rate. The fate of chemicals once they infiltrate groundwater is unknown. Groundwater once contaminated may persist for thousands of years and is generally considered irreversible.
SOURCES OF GROUNDWATER POLLUTION
Groundwater becomes contaminated in a multitude of ways, including some of the most ordinary human activities. As the water moves through the hydrological cycle, it interacts with the atmosphere, soils and subsurface geological formation. This affects its chemical composition and constituent’s concentration. Groundwater can become contaminated in multiple ways including some of the most ordinary human activities.
The main sources of ground water pollution are,
Domestic wastes
Industrial wastes
Agricultural wastes
Runoff from urban areas
Leachates from landfills
Mining and salt-water intrusion
Dissolved salts and minerals
CLASSIFICATION OF GROUNDWATER POLLUTANTS
TYPES OF POLLUTANT | EXAMPLE |
Organic pollutants | Carbohydrates, proteins, oils, aldehydes, polychlorinated biphenyl, phenol compounds, aromatic hydrocarbons. |
Inorganic pollutants | Acid, alkalis soluble salts, insoluble salts, polyphosphates, inorganic pesticides. |
Radioactive materials | Uranium, Radium |
Toxic chemicals | Lead, mercury, copper, cadmium, nickel, selenium, arsenic |
Plant nutrients | Phosphorous, nitrogen, potassium |
Pesticides | Herbicides, fungicides, insecticides, rodenticides, infanticides, synthetic pesticides. |
Biological pollutants | Bacteria, viruses |
Thermal pollutants | Heated water |
CONCLUSION
Groundwater is considered as most valuable natural resources.
Groundwater characteristics are above the standards of drinking water for most of the parameters.
The groundwater indicates both open and tube wells exhibit high levels of total dissolved solids and chloride.
The studies also indicate that the groundwater is unsuitable for domestic use.
In the earlier period the groundwater was fit for irrigation and at present water intensive crops have more or less disappeared from the villages.
About 15% of the total number of diseases caused to the cattle and pet animals may be due to water pollution.