Proposed Composting Plant and Final Disposal Facility at Maligawatte, Dompe

Dompe Pradeshiya Sabha belongs to Western Province and is located in Gampaha District with total extent of 178 sq Km. It consists of 133 Grama Niladari Divisions with about 168 townships. Kiridiwela has been the major township in the Dompe and the total population is about 130,195 as per the statistics collected in 2001. The density of population per one square km is 730 and number of housing units in the area is 34,793. Number of families amounts to 34,894 and the number of schools in the area total up to 47 respectively.

The average yearly temperature is about 80⁰F and average yearly rainfall is 1500 mm respectively. The storm water in the area drains to Kelani River.

At present, Dompe PS does not have a proper final disposal facility.  Dompe PS collects solid waste from market, main roads and commercial buildings totalling it to be around 10 metric tons per day. The MSW so collected has been dumped in a marshy area since there is no dedicated facility available for the area. The disposal in the marshy area seems to be open dumping with no daily soil cover on it. This has led to many environmental issues resulting in environmental pollution and enhanced health impacts on people in and around the dump site.

Dompe PS presently has a vehicular fleet of  05 four wheel tractors, 10 larger hand carts and 02 smaller hand carts for collection of MSW which is being accumulated within the urban areas and 14 number of personnel involved directly with the MSW management.  5% of the total income of the PS has been allocated for solid waste management by Dompe Pradeshiya Sabha. However the present practice adopted by the PS seems to be not adequate to solve this issue. Dompe Prdeshiya sabha has therefore requested the assistance from “Pilisaru” Project to improve their solid waste management system in an environmentally acceptable manner.

In response to the request made by the Dompe PS, Pilisaru Project has decided to facilitate both technically and financially a fully fledged final disposal facility encompassing composting yard and engineered landfill within the same locality. Korean Government has expressed their willingness to help establish landfill facility with state of art technology and the composting yard by the government of Sri Lanka through Pilisaru Project.

The total population in the Dompe PS becomes the beneficiaries of this project. The total compost production under this project will be estimated to be 1440 MT per year and annual income is estimated to be at Rs 10.06 millions. Expected net profit of this project is Rs 3.11 million per year. The compost so produced can be used as a soil conditioner and an alternative for chemical fertilizer.

There are a wide variety of alternative waste management options and strategies available for dealing with MSW to limit the residual amount left for disposal to landfill. Preliminary sorting is an important integral step which contributes to the diversion of MSW from landfill when operated as part of a wider integrated approach involving additional treatment stages such as separation by composting etc. Manual sorting, which is planned to be implemented in the proposed site prior to any other treatment is an important process in the entire system.

Once the manual separation of MSW is done biodegradable, non-biodegradable, recyclables and inert material components will be stored in different bins for further treatment. Biodegradable component is then sent to the composting facility, while non-biodegradables will be managed in landfill facility. Recyclables are stored in separate bins until sizable quantities are generated and subsequently they will be sold to respective industries for further value addition. The inert material mainly comprising earth will be utilized for filling purposes elsewhere.

The major components are handled in different corners of the land and perhaps different operators may be responsible for each facility operation. No attempt is taken to landfill all types together as the life time of the landfill becomes shorter and also value addition may not be possible. The concept described above is therefore the framework on which the entire proposed methodology is planned to be worked out at Maligawtte, Dompe.

The proposed facility consisting of both composting yard and landfill to be constructed and operated in Dompe, Maligawatte will make an important contribution in alleviating the MSW disposal problems faced by Dompe Pradeshiya Sabha to a significant extent.

In the overall assessment, there will not be major environmental impacts during operation except the risk of liner failure. However, there is adequate natural attenuation in the event of a leakage. Also contingency plans have been drawn to minimize the leakage in the event of liner failure. It is known fact that the methane (CH₄) quantity emitted to the atmosphere will be not very significant from the commencement of the operation. Some odor problems could result from the waste disposed on the site, which will be controlled as practical as possible with different methods. Similarly, the overall effects of odor will be marginal or the effects will be restricted to a shorter time period considering the fact that the wastes brought in to the facility will be immediately sorted and the subsequent sorted material will be treated accordingly. It is guaranteed that the best possible technologies for both composting and land filling be adopted so that the proposed project could become a good show piece to many.

The project will not cause any adverse social impacts with reference to relocation of any households/families. Although the neighboring communities and the Irrigation Department are concerned of the prevailing flood levels, they are of the view that adequate measures can be taken to reduce the environmental impacts of establishing and operating the proposed facility.

A comprehensive environmental monitoring programme of the different segments of the environment in and around the proposed site has to be carried out by the Project Proponent in order to assess the performance or success of the implemented mitigatory measures. In this respect it is advised to establish an Environmental Monitoring Committee.

In addition, it is crucial to have an operational plan which needs to include emergency response plans (Contingency plan) for emergency situations such as health hazard for workers; accidents, fires/explosions, flood and slope failures. These plans should be reviewed and revised periodically to keep the procedures fresh in employees’ minds and to reflect any changes in such items as the unit operating procedures, facility operations, changes in the wastes, generated volumes, addition or replacement of equipment, and personnel changes. If an emergency does arise, notification of appropriate agencies (Site manager, Site Engineer, Police, Fire fighting department, and adjacent land owners) is necessary. After emergency conditions have been cleared, it is crucial to review the waste management system and revise it (if necessary), to prevent similar mishaps in the future.

In considering the impacts together with mitigation proposed it is imperative that the proposed project could be implemented with the minimal damage to the environment. Further, as of today the technology proposed namely the aerobic composting together with engineered landfill would be the very first one proposed to be constructed in Sri Lanka with fully fledged state of art technology in place. The liner technology of HDPE with seaming facility is planned to be brought in to the landfill site and all critical parameters of designs were estimated with renowned experts in the world.

In conclusion, it could be inferred that the proposed technology, i.e. aerobic composting together with engineered land filling would be technically feasible, financially viable and socially acceptable at the proposed site.

Even though the proposed facility is ideal for the Maligawatte site, it may not be sustainable without a long-term plan with respect to the maintenance aspects of the infrastructure together with other ancillary equipment and machinery. It is therefore necessary to adopt a method by which funding is made available to cover up O & M expenses for the entire facility.

A suitable scheme of getting a tipping fee for the maintenance of this proposed facility is recommended for the sustainability of the entire project.