A Study On Sanitary Landfill In Western Province

Disposal of municipal solid waste (MSW) has become a national issue in Sri Lanka, due to its ever increasing quantities generated, lack of suitable lands for safe disposal, inadequate scientifically acceptable disposal facilities, inconsistent approaches adopted by the Local Authorities and public resistance and objection. One of the most critical problems emerging from rapid urban expansion is the increased quantities of waste generation, which needs proper disposal systems.

The total estimated generation of MSW in Sri Lanka is about 8000 Metric Tons (MT)/day of which the Western Province alone generates over 3200 MT/day (Feasibility study report, 2017). The daily generation within the Colombo Municipal Council is about 1,000 MT/day of which daily collection remain around 700 – 750 MT/day (Feasibility study report, 2017). The important feature is that any of the Local Authorities in the country does not collect all the MSW generated within their jurisdictions. (Feasibility study report, 2017).Handling waste is a hectic task for responsible organizations such as local authorities irrespective of the nature of the waste.

This has not confined only to household but for the industry too facing severe difficulties when come to dispose of waste generated due to day-to-day activities. Haphazard methods adopted by various entities including households cause huge problems not only long run and their immediate effects are very disastrous. Two good examples are very famous mostly talking incident of Ratupassala and collapse of Meethotamulla dumpsite. In both incidents the country loss not only properties but also the lives.

As mentioned above the waste slide event occurred at the Meethatomula dumpsite in Colombo, the capital of Sri Lanka was a revelation to all parties concerned. The dumpsite was large, holds about 1 million-m3 volume of waste, and its area is 412x215 meters. Extensive damage to life and property includes 32 people dead, 8 people missing, 264 families affected, 79 houses fully damaged, and 17 partially damaged.

There remain risks of further slope failure, fire, methane gas emissions, etc. In terms of disposal, haphazard solid waste disposal has been identified as one of the major causes for Environmental degradation. The most common method of disposal of MSW remains to be open dumping, which will cause contamination of soil, surface and groundwater, emanate repulsive ordor and emit toxic gasses especially when burnt in the open areas, threaten human and eco-system health directly and indirectly, causes ugly and unpleasant environment finally leading to socioeconomic and political issues.

The main institution dealing with the aftermath of the event is the Ministry of Megapolis. A number of other Government institutions including the Ministry of provincial Councils and Local Government, the CMC, the Sri Lanka Land Reclamation and Development Corporation, the Urban Development Authority (UDA), the Waste Management Authority, the Central Environmental Agency, and Sri Lanka Railways supports megapolis. The Government’s response is divided into two phases: (1) control of further collapses and potential stabilization of Meethothamulla dump site; and (2) development short, medium and long term solutions for the integrated management of solid waste. As a measure to handle Municipal Solid Waste generated in the Western Province the government has started a sanitary landfill in Dompe with the assistance from Korean Government under Central Environmental Authority. This is the only sanitary landfill that the country is having to date and can cater only about 100 Metric Tons per day At present, especially after the meethotamulla incident, the Government of Sri Lanka has identified the severity of this issue and has been giving utmost priority to find a longlisting and sustainable solution to this issue. Since the Meethotamulla event, the site is a closed area and is not accepting any further dumping.

The Government initially received a court order that allowed the Colombo Municipal Council (CMC) to dump waste at Karadiyana dumpsite (350t/day) until April 28, 2017.Following this, the Government identified a site at Kerawalapitiya to be constructed as a “temporary engineered landfill”, which will receive approximately 350MT/day (approximately half of the volume of waste from CMC that was previously going to Meethothamulla), with an operating horizon of about 2 years. The site will also include a large-scale composting facility that will receive up to 300MT/day of segregated organic matter from CMC.

The definition of Municipal solid waste is a waste product in urban areas and usually applied to a heterogeneous collection. The generation of Municipal solid waste from house, Office, school etc. Municipal solid waste was no value to them. However, it may be value or recourse to someone else.

In simply saying, collecting and disposing of solid waste is the process of collecting solid waste from the processing point-home, factory or hotel, and transporting them to the disposal site without creating any nuisance to the human life in a healthy manner. Most often, in many parts of the country Management of solid waste is not adequate or not in the required standard, due to lack of knowledge or resources or not understanding the importance of it. With the growing population of urban area, especially solid waste collection and disposal is a very important factor in urban life, because it may cause severe health hazards and social problems. In my point of view in Sri Lanka, though government is vigilant, the community is not aware of its importance. Local authorities do not practice proper solid waste management systems.

Municipal Solid waste management in Sri Lanka is unsystematic. Local government, Authorities have implanted different methods, most notably, some methods are operating poorly, in abandoned halfway. Analysis of present solid waste management methods to identify the gaps is my research approach. Content analysis was used to analyze collected data, which is the method involves establishing categories and then counting numbers of instances that fall into each category. This method pays particular attention to reliability of its measures and to validity of its findings.

In order to obtain both qualitative and quantitative data, survey focused on the present solid waste disposal practices, their attitudes to solid waste and the level of involvement of recycling, including home composting.

The National strategy for solid waste management were passed in 2000 May with the aim of managing solid waste at first minimizing the solid waste and then to dispose. The minimizing of solid waste through the three R s. (Reducing, Reuse and recycling). Apart from, Local Authorities were encouraged to take central level actions such as find ways for sale of recyclable waste and produce, products from recyclable materials. Under the above strategy, “Pilisary Programme” was launched with the following Objectives:

1. To establish island wide paper conservation of resources and paper solid waste management.
2. To create awareness regarding, “issues related with Management of solid waste among relevant personal and improve their skills
3. Implementation of solid waste management projects and monitoring.
4. Providing Facility, including financial facility.
5. Establishing waste Recycling Banking System.
6. Legal actions for Local Authorities, which do not dispose solid waste in the proper manner.

In order to fulfill above objectives some main activities were introduced.

Disposal Practice

Open dumping is the most common method of disposal and it account for more than 85% of the collected waste. These sites were no engineered sited where waste is tipped haphazardly without environmental protection marshes and abounded paddy fields are mostly filled as a reclamation method. Some instances a daily topsoil cover was used to minimize nuisance and ally the public opposition. In these dumping sites, no segregation is done and disposes every type of waste such as industrial, hospital, and clinical, slaughter house wastes together with household wastes. No steps taken to manage the leachate or control pollutants released from waste decomposition.

Basic operations such as leveling or covering of waste at the site are exists, due to high costly involved or negligent. Soil cover is applied at the final stage when there is a projected use of the lard or public pressure dumping by individuals also takes place along streets and on marshes or land abounded lands. Local authorities taken little control over these mal practices because of a lack of resources or stringent laws.

Current Problem

The Accumulation of uncollected solid waste public places and the improper handling of wastes during transportation, disposal, and scavenging have become major health and safety issues in Sri Lanka. Insects, rodents and other vectors are attracted to the waste and can spread communicable, diseases, such as dengue fever. In addition, use of water polluted by solid waste for bathing, cooking, irrigation and drinking cloud expose individual to diseases pathogens and other contaminants. Obstacles to implementing proper solid waste management systems by local authorities in sir lank included inadequate facilities for final disposal introduction of improve solid waste management ,lack of knowledge ,technology and expert ices about waste poor planning and management .high cost of collection attitude of people and responsible local authority to wards waste.

Municipal solid waste management is a serious environmental and socioeconomic issue in Sri-Lanka and haphazard disposal of solid, rapidly increasing quantities and diverse characters of waste will have accelerated it further local authorial are running with a financial and technical burden for waste management as well as pressure on land fill requirements. In the planning stage itself there are gaps in local authorities and stakeholder levels that will lead to ineffective.

One of the main sources of water pollution land fillings. The classic example is the filling of the Gohagoda water plan in Kandy. Further there is several boreholes locate close proximity of the land fill, used for drink and domestic purposes.

A study of composition of land fillings leachate and ground water pollution conducted at Gohgoda site. In addition, it directed the seasonal variations of the water quality in the nearby water wells. The results showed that leachate of the landfill were most likely methanogenic phase based on the alkali me PH value recorded. These results also showed that significant number of borehole were contaminated with physio-chemical parameters are above the WHO standards required for drinking water. Therefore, it is clear that this type of Landfills is a threat for the environment, and authorities should do sanitary Landfill to prevent such situation.

Considering all these factors and figures, the Sri Lanka government has taken positive steps implementing towards effective and efficient solid waste management strategies. The organizational responsible for solid waste management in Sri Lanka are the central government, Ministry of Environmental and Natural Resources, Ministry of Local government and Provincial councils, Ministry of Health, Central Environmental authority, Urban development authority, Provincial Councils, Waste management authority in western Province.

For the hindrances free functioning of this solid waste management pertains some legal enactments such as Municipal council ordinance, urban council ordinance, urban council ordinance Rural Local authority act, are implemented. National environmental act was enacted in 1980, and amended in 1988.This act provided the required legal frame to establish the Central Environmental authority, and defined the powers, functions and duties. Having done various researches and studying the best practices around the world Sri Lankan government has taken steps to introduce on Sanitary land fill projects in selection area. Moreover, at the same time, fostering the ability of systematic operation and maintenance in landfill facilities. The sanitary landfilling will be helpful in minimizing environment pollution and contamination, preserving a comfortable urban environment and will improve the living environment of residents, further it were hoped that it would pave the way to increase the Percentage of recyclable materials, decrease the waste volume being sent to landfill by composting organic waste. More importantly, it will pare the way to reach the worldwide campaign for a sustainable development and millennium development goals.

Sanitary landfill technology

Sanitary landfill is a method of controlled disposal of municipal solid waste (refuse) on land. The method was introduced in England in 1912 (where it is called controlled tipping). Waste is deposited in thin layers (up to 1 meter, or 3 feet) and promptly compacted by heavy machinery (e.g., bulldozers); several layers are placed and compacted on top of each other to form a refuse cell (up to 3 meters, or 10 feet, thick). At the end of each day the compacted refuse cell is covered with a layer of compacted soil to prevent odors and windblown debris. All modern landfill sites are carefully selected and prepared (e.g., sealed with impermeable synthetic bottom liners) to prevent pollution of groundwater or other environmental problems. When the landfill is completed, it is capped with a layer of clay or a synthetic liner in order to prevent water from entering. A final topsoil cover is placed, compacted, and graded, and various forms of vegetation may be planted in order to reclaim otherwise useless land e.g., to fill declivities to levels convenient for building parks, golf courses, or other suitable public projects. Landfills are often the most cost-efficient way to dispose of waste. While resource recovery and incineration both require extensive investments in infrastructure, and material recovery also requires extensive manpower to maintain, landfills have fewer fixed or ongoing costs, allowing them to compete favorably. In addition, landfill gas, primarily of methane, a leading contributor to global warming, can be flared or upgraded to natural gas. Another advantage is having a specific location for disposal that can be monitored, where waste can be processed to remove all recyclable materials before tipping.

Basic Components of a Typical Landfill

1. Bottom and Sidewall Liners
2. Leachate collecting Pipes
3. Leachate Treatment Plant
4. Strom water Drainage facilities
5. Gas Collecting Pipes
6. Tyre washing bay
7. Weighbridge
8. Protective Fence
9. Ground water Monitoring well

Bottom and Sidewall Liners

A landfill liner, or composite liner, is intended to be a low permeable barrier which is laid down under engineered landfill sites. Until it deteriorates, the liner retards migration of leachate, and its toxic constituents, into underlying aquifers or nearby rivers, causing spoliation of the local water.

Modern landfills generally require a combination of different types of synthetic liners sandwiched into a layer of compacted clay with a minimum required thickness and a maximum allowable hydraulic conductivity, overlaid by a high-density polyethylene (HDPE) geomembrane.

Leachate collecting Pipes

A network of leachate (the black color liquid wastewater that is formed by the decaying of waste) Collecting perforated pipes will be laid down towards the bottom of the landfill to collect the leachate Passing through the masses of waste. The collected leachate will then be piped out of the landfill for Treatment at a Waste Water Treatment Facility.

Leachate Treatment Plant

There are many components in a leachate collection system including pumps, manholes, discharge lines and liquid level monitors. However, there are four main components, which govern the overall efficiency of the system. These four elements are liners, filters, pumps and sumps.

Strom water Drain System

A storm water drain is designed to drain excess rain water from roofs, buildings, and other open areas of the sanitary landfill site. Storm water drain is essential in a landfill to avoid mixing of feely flowing drain water with the leachate generating in the working cells of a landfill thereby the reducing the quantity of waste water destined for treatment.

Landfill Operation

Proper operation of a sanitary Landfill plays an important role if the environmental and health safeguards are to be achieved ensuring safety of the public. Typically, operators of well-run landfills for non-hazardous waste meet predefined specifications by applying techniques to • confine waste to as small an area as possible• compact waste to reduce volume• cover waste (usually daily) with layers of soil or other types of material such as woodchips and fine particles.

During landfill operations, a scale or weighbridge may weigh waste collection vehicles on arrival and knowledgeable personnel may inspect loads for wastes that do not accord with the landfill's waste-acceptance criteria. Afterward, the waste collection vehicles use the existing road network on their way to the tipping face or working front, where they unload their contents. After loads are deposited, compactors or bulldozers can spread and compact the waste on the working face. Before leaving the landfill boundaries, the waste collection vehicles may pass through a wheel-cleaning facility. If necessary, they return to the weighbridge for re-weighing without the load. The weighing process can assemble statistics on the daily incoming waste tonnage, which databases can retain for record keeping. In addition to trucks, some landfills may have equipment to handle railroad containers. The use of "rail-haul" permits landfills to be located at more remote sites, without the problems associated with many truck trips.

Typically, in the working face, the compacted waste is covered with soil or alternative materials daily. Alternative waste-cover materials include chipped wood or other "green waste", several sprayed-on foam products, chemically "fixed" bio-solids, and temporary blankets. Blankets can be lifted into place at night and then removed the following day prior to waste placement. The space that is occupied daily by the compacted waste and the cover material is called a daily cell. Waste compaction is critical to extending the life of the landfill. Factors such as waste compressibility, waste-layer thickness and the number of passes of the compactor over the waste affect the waste densities.