Optimizing solid waste management technologies appropriate for small and medium scale local government authorities in sri lanka

Abstract

MunicipalSolid Waste (MSW) is a growing problem in Sri Lanka and this problem is aggravateddue to absence of a proper Solid Waste Management (SWM) system in the country.Althoughthere are several SWM programs that have been implemented in some of theLocalGovernmentAuthorities(LGAs) in Sri Lanka, there had been no standard procedure tomanagethe amountof waste that is being generated. Composting, bio gas generation, semiengineeredlandfill and recycling are the key waste treatment technologies available in Sri Lanka. Theobjectivesof this study were to (i) evaluate the effectiveness of household, community andlocalgovernmentauthority level initiatives in SWM, using the USAID/OTI funded SWM programfor Galle and Weligama UC SWM programs as case studies; (ii) to identify and optimizekey operational parameters of MSW composting processes at the household, communityand local government authority level in order to increase the rate of decomposition. Galle Municipal Council and the Weligma Urban Council were selected as two study locations.To studythe effectiveness USAID/OTI funded SWM project in Galle, primary data werecollectedthroughinterviewsand by directobservations.Totalof eightyhouseholdsand five communitymobilizers were selected randomly from all five MC wards. Data were analyzedusingfrequencies,percentages, chi-squares using SPSS and Minitab. Effectof aeration on the rate of degradation of household bins was studied by turning the materialsin five bins at weekly intervals and not turning the materials in the other five bins. Theeffectof aeration and the moisture content on the rate of degradation on the commercial levelcomposting piles were also studied. Volatile solids, temperature, moisture, volume reductionand the particle size were measured and recorded. The data were analyzed and presentedastime seriesplots, tables, etc. Thefindingsof the Galle SWM project revealed that, the majority of the respondents (70%) donotpracticehousehold waste sorting and 62.5% said the separate collection by GMC is not functioning.Only 16.25% are using the community compositing units. None of them is functioningas expected. Overall the techniques and technologies introduced to GMC have not beensuccessful.Although, the rate of degradation of materials in the household composting binsdidnot show any difference with or without turning, the commercial scale composting showeda difference in VS reduction in the turned and not turned piles. Also, there was no differencein the rate of degradation in the piles with controlled or without controlled moisture. It can be concluded that a higher level of political commitment is compulsory for implementinga better managed SWM program. Community composting is not a good solutionto manage the waste. Turning the materials does not have any effect in household composting,but the rate of degradation is higher in commercial level composting, when the piles are turned. The excess moisture received from rain does not affect heavily if the materialsin the piles are turned frequently. A combination of household and LGA level SWM practicescan be proposed to develop a SWM system suitable for small and medium scale LGAsin SriLanka.