Master of Engineering in Environmental Engineering & Management

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item: Thesis-Abstract
An Appraisal of the small town water supply schemes in Kuruwita & Kalawana which were implemented with user community participation
Samarasinghe, KPRS; Ratnayake, N
This study was based on Small Town Water Supply Schemes which were constructed in Ratnapura District under a World Bank loan and implemented with user community participation. The study was limited to the first two Small Town Schemes, constructed by National Water Supply and Drainage Board, in Kuruwita and Kalawana small towns. The aim of the study was to evaluate the success with regard to technical and social aspects of the above two schemes implemented with active community participation during planning, construction and operation and maintenance phases. Technical aspects were compared with similar schemes constructed by National Water Supply & Drainage Board without participation of users while social aspects were compared by analyzing social improvement of the area before and after the new schemes. Technical data were collected from National Water Supply & Drainage Board offices. Social aspects were evaluated by using field survey with questionnaire and interviews. The study shows, for a sustainable Water Supply Scheme, it is necessary to obtain a user participation in planning, construction and operation & maintenance phases. In the planning stage of a community water supply scheme, it is necessary to obtain a user participation, because all the relevant data for accurate planning are available at the place where the scheme to be built; and also it is easy to collect data from users rather than collecting by out side officers or any other person. During the construction period it is also necessary to participate users to aware about quality of work, major components of the scheme, how to operate the scheme, and methods using for construction etc. Those will help to go for the sustainable operation and maintenance of a scheme. Sustainable Operation and maintenance system is the main objective of community water supply scheme. Therefore it is necessary to participate users during operation and maintenance of scheme, because the scheme should run to full fill their requirement.
item: Thesis-Abstract
Analysis of transmission phase out options in water supply projects
Perera, ULDND
A study on "Analysis of transmission phase out options in water projects" was carried out to analyze possible cost savings to meet any the financial constraints of the project and also to utilize available funds for the benefit maximization through implementation of most customer friendly projects considering the opportunity costs. In order to achieve this target, the TNC water project was selected as a case study and an independent study on duplication of pipe lines were also carried out parallel, to support the analysis. The data required to analyze the transmission system of the TNC project and also to perform the economic analysis on the duplication of pipe lines were collected from the TNC project office, MIS Nihon Sudio consultants I Cey water consultants, NWS&DB and from the University of Moratuwa. The analysis of phase out options of the transmission system of TNC project was carried out by formulating 2 options based on the designs carried out by MIS Nihon Suido consultants. As per the designs carried out by the consultants, the nodal point demands and the bulk demands could be identified separately and the 10th & 20th year demand were rearranged to identify the nodal point demands of each options proposed. Then the "Water CAD" software was used to identify the diameters of transmission lines for the proposed phase out options. The supply and laying costs of DI pipes and specials were calculated and forecasted the future cost figures through reasonable justifications due to abnormal price variations appeared. Then the costs of each transmission line for the proposed options at their implementation stages and the cost of full transmission system were calculated. The present worth of both options was compared with the full transmission cost and the additional funds required for the implementation of both options were then calculated. Based on the above additional fund requirement, the economical interest rates applicable on the decisions of the implementation of each phase out options were calculated. Addition to the above case study analysis, an independent study on pipe line duplication in two different scenarios, theoretical analysis and practical situation based on BS4772 (1988), were also performed and the economically viable diameters of pipe line duplications were identified. Based on the results obtained through both of the studies, the conclusions were made on the economical duplication of pipes in transmission phase out options of water supply projects,
item: Thesis-Abstract
Assessment of the Capacities of Community Based Organizations for Sustainable Management of Small Town Water Supply Scheme
Ranasinghe, KSK; Ratnayake, N
Poor water supply & sanitation services continue to be critical problems in rural areas despite considerable effort to improve and expand coverage. Mounting evidence indicates that centrally managed schemes, are difficult to implement and operate when the communities served are dispersed, remote and relatively small. Application of sophisticated technology in such systems leads to high cost in implementation and management that are unaffordable to manage. High O&M and management costs need to be covered by charging high tariffs. Beside above there is a ·lack of financial resources and physical and social infrastructure needed to support development or to maintain new systems. In contrast, locally managed systems appear to function reasonably well at affordable prices and looks to be sustainable. Although such schemes are obviously difficult to standardize for all communities due to the unique nature of each case, water & sanitation experts agree that they have numerous advantages over other approaches and that the question is no longer whether community management should be promoted, but how it should be done. In the study, attention was focused towards the sustainability of the provided water supply and sanitation facilities. To sustain the facilities over a long period of time capacities of managing agencies should have acceptable standards. The main component of the study was assessing the capacities of the Community Based Organizations that are vested with power and authority in the management of rural water supply schemes covering the small town category. Study was carried out by observing the situations of six locations where small town water supply schemes have been constructed. Some of these schemes are managed by the local authorities and some by the implementing agencies like NWSDB. NWSDB and local Authorities are powerful legal entities with an established institutional strength recognized by the legislature and the society. However the conditions of CBOs are not that fascinating. Therefore capacity assessment was made focusing the CBOs to a greater extent and the achievements of CBOs were compared against the outputs and performance ofNWSDB & LA set up as well. The six small town schemes studied are diverse in the form of technology adapted, and the nature of management. Therefore, thought had to be extended to various aspects representing these special features while carrying out the assessment. Since all the schemes are planned, implemented and managed with effective involvement of the users in the demand driven environment under the participatory background, the research study was also executed in participatory basis. 3 Study was carried out by conducting interviews with user communities, obtaining data by distributing a questionnaire, making observations by participating in community meetings and monitoring and evaluating the performance of CBOs by interacting with the communities in progress meetings, during the implementation stage of the project. Data gathered from the collected information were analysed to study the aspects given in the objective of the research. Findings of the study were presented comparing the .outputs of different maintaining agencies of water supply schemes such as CBOs, LAs and NWSDB. Inputs from district sociologists were obtained when social aspects of water were addressed. This thesis describes the out come of a study carried out to assess the Capacities of Community Based Organizations (CBOs) in various aspects of user centred water supply schemes, taking six small town schemes as case studies as described above.
item: Thesis-Abstract
Assessment of the degree of public awareness on Tsunamis in Galle district, Sri Lanka
Kumara, AGG; Rathnasooriya , H; Samarawickrama, S
Tsunami is one of the most devastated coastal hazard, which may perhaps yields serious damages to both human lives and properties in affected islands like Sri Lanka. As an island, Sri Lanka has also become a Tsunami prone risk zone as frequent earthquakes reported in Java Sumathra region. Knowledge and the awareness on such coastal hazards of the community is a vital facts, which results is minimizing its adverse effects. Developing awareness processess and effective communication systems will definitely assist in the designing of hazards maps and evacuation plans. 26th December 2004 Tsunami has hit the Sri Lankan coastal regions creating many lives losses and property damages as a result of lack of previous experience in similar typed hazard. Focusing the assessment of public awareness and subsequent responsiveness on Tsunami, the study was planned to evaluate degree of awareness in the general public on Tsunami responsiveness and counter measures to be adopted. The survey was carried out in two stages as pre and post second anniversary of December 2004 Tsunami event. At the survey, 1200 sample was selected based on geographical representations of affected Grama Niladhari Divisions. School community and the general public are substantially encountered at the survey. A questionnaire was used to collect data from the sample and informal discussions were conducted to collect additional information. The survey was conducted by a team comprising of Engineers, Sociologist etc. The data collected was analyzed and results are presented in the report. Media effect, communication gaps, reliability of early warning systems, public responsiveness, suggested countermeasures are the critical outcomes of the study which needs to address at policy level. Ill
item: Thesis-Abstract
Composting of municipal solid waste
Weerasinghe, TJ; Ratnayake, N
The Colombo Municipal Council dispose of the solid waste by dumping on open marshy land. The land suitable for dumping waste, was fast exhausting and as a mean of lengthening the life time of the available dumping areas, the CMC decided to do a pilot study to determine the feasibility of converting solid waste into compost. Prior to the pi lot study, two other studies, (1) a survey on the production of compost in Sri Lanka, on commercial basis (2) a literature survey, were done.// Three organizations that produce compost on commercial basis were surveyed under the first study. They are, 1. Hiat Aggro Ltd. 2. Department of Agrarian Services 3. Water Resources Board Hiat Agg"ro Ltd. use coir waste, leaves and poul trydroppings to produce compost. Most of the compost produced by this company, are exported and the rest is sold in the local market.// The compost produced by a cultivation officer for the Department of agrarian Services, using garden waste and cow dung, in pits, are sold by the Dept. of Agrarian Services in 1 kg. packets.// The compost produced by the Water Resources Board ,using grass cuttings and cow dung is used in it's plant nursery and the excess is sold in 2 kg. packets, at the sales outlet of the Board.// The second study was on the research work that has been carried out, world over, on composting of municipal waste. The literature survey revealed that there are several fundamental factors that are applicable to a composting operation, such as, carbon to nitrogen ratio, temperature, moisture content ,shredding, aeration, etc.// The last study was the pilot project, where the behavior of six municipal waste piles were studied under different conditions of carbon to nitrogen ratios and aeration. Urea was used to lower the C-N ratio and aeration was provided by using aeration frames.// The non compostable material could be sufficiently removed by hand picking and sieving. The carbon to nitrogen ratio of the waste, in the piles, studied under the pilot project, varied from 23to 88, and within this range, waste decomposed at a fairly satisfactory rate, stabilizing within an almost qual time period. The rate of decomposition retards when the moisture content is over 55% and the optimum range is 40% to 50%, which can be maintained by wetting the piles once in 2-3 days. The solid waste of the Colombo Municipal Council, can be converted into compost in about 40 days, maintaining a temperature above 60 C, within the pile, for over 7 days. • when the particle size is less than 2 inches ( 5 cm ). • when piled on an aeration frame and turned once in 3-4 days. • when moisture content is maintained between 40 and 50%, by wetting once in 2-3 days.// The compost, produced, is more suitable to be used as a soil stabilizer, as it is, and if it is to be used as an organic fertilizer, it should be supplemented with phosphorus. Compost, from municipal waste, can be produced as an odorless, dry powder..
item: Thesis-Abstract
A critical appraisal of the water supply and sewage disposal arrangements in the univesity of Moratuwa
Sabanesan, SS; Ratnayake, N
A convenient supply of safe water and the sanitary disposal of human wastes are essential ingredients of a healthy, productive life* With this in view a critical appraisal of the water supply and sewage disposal arrangements in the University of Moratuwa was undertaken to explore suitable means of improving the system- Thereby a more satisfactozy and efficient service for the present and the future will be ensured* In this study consideration has been given to the suitability of the present sources in terns of location, quality, adequacy, storage facilities, etc* with regard to existing water supply system* In assessing the sewage disposal arrangements presently prevailing attention has beoi focused on such aspects as location of 3ewers, manholes and treatment units, etc* Further a detailed investigation into the working of the existing treatment units was also undertaken in order to assess the performance of these units in terms of 20 and SS. removal of BOD5 Investigations revealed the inadequacy and inefficiency of the present water supply system* There is evidence of faecal contamination of groundwater* Improper operation and maintenance of the sewage disposal system have resulted in its overall inefficiency* Provision of a central water tower of capacity of 120,000 gallons and centralised pump house is recommended* Further, provision of a simple water treatment unit is suggested* The need for immediate repairs to unit No: 2 and the disinfection of all sewage effluent are highly favoured* 3 The introduction of a new central sewage treatment unit incorporating as far as possible the present sewers and manholes is recommended. To obtain a satisfactory and efficient service a proper management of the water supply and sewage disposal arrangements is essential.
item: Thesis-Abstract
Development of a technical manual for pumping istallations in the water industry with emphasis on water supply systems
De Silva, LSPJ; Ratnayake, N
Pumping stations must be highly reliable. energy saving and economical. while at the same time their capital costs, operational and maintenance costs should be minimized. A technical manual for the multi disciplinary set of expertise who design, construct, operate and maintain pumping installations will help to achieve better performances. The objective of the manual is to impart knowledge on main plant and equipment, infrastructure and associated practical behaviour in pumping installations to those who design, construct, operate and maintain pumping installations. This manual covers planning, design, operation and maintenance aspects, main and ancillary equipment, and also practical behaviours. Chapter 1 has been devoted to discuss the important aspects of pumps needed for designers, operation and maintenance staff. Starting with the classification of pumps, the basics have been covered. Use of system head curves in different situations and affinity laws have been dealt with giving examples. NPSH has been dealt with critically. Pumps in series and parallel, effects of cavitation and recirculation causes of noise and vibration have also been covered. The importance of taking precautions to ensure proper design of sumps have been highlighted in Chapter 2. The adverse effects on pumps and its facilities that can result due to poor shapes and dimensions of sumps have been discussed. Basic dimensions. shapes. undesirable suction layouts and their improvements are provided to avoid mistakes. Chapter 3 summarises the guarantees and the acceptance tests for centrifugal pumps. This chapter will be useful mainly to those who are engaged in pump and other equipment testing and the approval of their performances. Chapter 4 is about pressure surges in pipe lines. The causes for pressure surges and different surge prevention measures have been discussed so that the most appropriate method for a given situation can be selected. A sample calculation has been included. Chapter 5 is on electrical equipment. Power supply and power factor, drivers, different starting methods, motor enclosures. motor protection, ratings and selection of motors, effect of temperature on life of motors, protection of electrical equipment etc. have been dealt with. Chapter 6 on pipe work valves and fittings will assist the Design Engineer to design and size the pipes and valves in pumping stations properly and the erection engineer ..to install them. Recommended flow velocities and a comprehensive list of head losses in valves and fittings have been included. Chapter 7 is about basic planning and design 'aspects of pumping, stations. Importance of minimisation of capital, operation and maintenance costs have been highlighted. Investigation procedures. Selection of pump types, number of pumps, pump speed, layout of equipment, electrical facilities. Positive and negative suction conditions have been discussed. Planning of electrical facilities and energy conservation have also been covered. Chapter 8 is about the civil engineering aspects of pumping stations. Importance of looking into civil as well as mechanical and electrical aspects have been highlighted. Chapter 9 deals on seven practical applications related to pumping stations. Vertical vs Horizontal pumps. performance of submersible pumps and methods of reducing energy costs. decision on whether to repair or replace the pumps. wear caused by sand in-intakes. choice of pump to suit system head. gland packing or mechan-ical seal are the areas covered. Chapter 10 covers the important points and how to size the ancillary equipment such as lime and alum pumps. blowers, chlorinators and overhead cranes. Ditferent types of now meters too have been discussed. Finally Chapter 11 summaries the aspects of operation and maintenance activities in a pumping station.
item: Thesis-Abstract
Development of an analytical model to studywave motion to through porough porous vertical to coastalstructures
Samarasekara, MMPD; Hettiarachchi, SSL
This study is concerned with the development of an analytical model to predict wave reflection and transmission characteristics of porous, vertical coastal structures. Because of the complexity of the problem the study was limited to non-breaking, small amplitude, long waves normally incident to the structure. The input data for the model are the incident wave characteristics and the properties of the porous media. The wave climate is identified by the wave height, the wave period and still water depth. The porous structure is characterised by its length, overall porosity and the laminar and turbulent flow coefficients (determined under steady flow conditions). The Forchheimer equation was used for the hydraulic gradient-velocity relationship. Continuity and momentum equations are linearised for the inclusion in the model. The model was verified with results obtained from hydraulic model investigations carried out at Imperial college, London and Lanka hydraulics institute, Sri Lanka. Satisfactory agreement was obtained between experimental and predicted values. 11
item: Thesis-Abstract
Effect of antimicrobial discharges into wastewater treatment plants in the pharmaceutical industry
Gunasekera, MY; Abeygunawardane, I; De Alwis, A
Pharmaceutical manufacturing industry is expected to generate effluents having a wide variety of antimicrobial substances. The biological wastewater treatment processes should thus be capable of handling effluents, containing these inhibitory materials, without being adversely affected. In this investigation, the study of the wastewater treatment system of a Pharmaceutical Manufacturing facility is carried out with special reference to antimicrobial discharges. The manufacturing process studied dealt with formulation, filling and packaging of preparation for prescription products. Thus this facility falls into the 'dry formulation' category. A good clean supply of water is essential in this industry. The water used in the manufacturing areas is mainly for cleaning/washing of processing equipment and accessories. Water is also used for cooling the housing of the moving parts in machines. All liquid effluents generated pass through a wastewater treatment plant prior to discharge into an inland surface water body. The wastewater treatment plant in this facility consists of an activated sludge treatment process. For a primary understanding of this wastewater treatment plant a study of the general characteristics were done. The effect on the overall efficiency of the wastewater treatment plant was observed while studying the washing/cleaning activities carried out in the production zones on each sample collecting day. The findings of this study showed an overall efficiency less than the design efficiency of the wastewater treatment plant. It is seen that plant inputs and generated waste loads are low even when compared with typical waste characteristics of such facilities. A large fraction of the BOD/COD ratios determined showed low values. About 92% of the BOD/COD ratios determined in the equalization tank were less than 0.5. The analysis of BOD, with different dilutions was done in order to determine whether there is an effect by any antimicrobial substance on the biological activity. IV The BOD test carried out for a series of wastewater sample dilutions showed decreasing BOD values as the dilution percentage increasing on certain days. In some days results showed 31% to 34% reduction in BOD value indicating the presence of an antimicrobial substance in the wastewater sample on that day. Further, in order to study the antimicrobial activity of the wastewater discharged from this facility, E. coli was tested in liquid culture medium. The growth of E. coli was monitored as absorbance at 600nm in the presence and absence of waste samples. The results indicated the growth of E. coli in wastewater was not as high as the growth shown in the peptone water medium. It was also indicated that the growth of this organism in the wastewater sample was not inhibitory as in the solution containing amoxycillin (1011g/ml). A study of the effect on the same organism was also carried out using the antibiotic diffusion technique. The inhibition zones created from a concentration series of an antimicrobial substance were studied with the inhibition zone produced by wastewater. The study carried out using the cylinder plate test showed an inhibition zone for wastewater. For a wastewater sample taken from the wastewater treatment plant after cleaning Rifampicin processed machines, a clear zone was observed giving an effect equivalent to a concentration of2.9 ug of amoxycillin per milliliter. From the observed results, heavy impact on the wastewater treatment plant operation from discharges was not indicated. However the precautions are needed to be taken when contemplating expansion etc. as the present observations and conclusions apply only to current loading conditions. Close monitor of waste effluent would be necessary in future if expansion is sought by the company.
item: Thesis-Abstract
Effectiveness of five rural water supply schemes implemented under RIWASH project in Batticaloa District
Dharmarajah, AP; Manatunge , JMA
In Sri Lanka more than 60% of the population living in rural area does not have access to safe drinking water. As per census records of 2001, 75% of total population are living in rural areas and do not have proper water sanitation facilities, which can be directly related to health hygiene and income generation of rural community in Sri Lanka. Sri Lankan National Policy states the government's goal is to provide clean water and safe sanitation to all its citizens by 2025. However, progress toward this goal has been hindered by a centralized delivery system, inefficient intra- governmenta processes and limited capacity at the local level to manage water and sanitation systems. More recently, the Government of Sri Lanka has taken steps to address these obstacles through a national policy for Rural Water Supply and Sanitation Sector (RWSS). The RWSS aims to shift the responsibility for delivery of water and sanitation services to, Local Government, civil society and private sector organizations. Towards the achievement of Millennium Development Goal (MGDs),in 2025, Government of Sri Lanka has taken steps to develop the RWSS Schemes in every part of Sri Lanka. In the Batticaloa District there were no rural water supply schemes implemented in the past years due to disturbances and displacements of people in the rural villages. The only piped water supply is that implemented by the National Water Supply and Drainage Board in the urban area to cover Batticaloa and kattankud town limits. Generally in all villages there is scarcity prevailing for drinking water. Villagers fulfil their drinking water needs by obtaining water from the nearest village. For their household and other needs, irrigation tanks and channels are being used. This water too is of undesirable quality and the quantity is inadequate. There is a possibility of spreading of waterbom < diseases in these villages as most of the people are directly consuming the water without any treatment or even boiling. During the dry season the situation becomes worse. Normally in villages of this nature, it is the women who fetch water in pots and cans. It is expected that with provision of an appropriate water supply system, their burden will reduce in going out in search of water and carrying back to their houses. It is also expected that the housework will be made easy by availability of pipe-borne potable water. Most of Non Governmental Organizations (NGO's)worked in these villages, were focused on upgrading the living standard of the people by encouraging them for self employment, cultivation and income generation modes, but rarely on water and sanitation issues. Therefore, the people of these villages were expecting to fulfil their basic need of obtaining drinking water through rural water supply schemes implemented in their villages. IV
item: Thesis-Abstract
Environmental aspects of drainage systems in road projects
Ravindralingam, K; Ratnayake, N
Drainage systems in Road projects should be given due consideration because it influences the environment. The purpose of this research project is to study road drainage systems, as to how these affect the environment and how environmental factors affect the road, and what type of recommendation could be considered for effective, efficient and best use of the system to use in the anticipated road projects. This study is mainly concerned with the surface drainage system of the road sector. The areas selected for this study are Hakmana Town Intersection in Matara district, 1.3 km Road section from Imbulgoda on Colombo -Kandy road and Kiribathgoda Town intersection on Colombo Kandy road. The data such as Flooding, health problems, Accidents, Condition & maintenance of road drainage systems were collected through questionnaires, levels of the road profile were taken through surveying and the maximum intensities of the rainfall were collected from the department of Meteorology. Design and statistical analyses were carried out using the data. According to analyses, it was found that maintenance work influenced the flood, health problems in these sites were caused only by mosquitoes breeding and mosquitoes breeding were occurred not only by the flooding but also by the disposal of solid waste. According to this research study, it was found that the flood was the main environmental issue of drainage systems in the road projects. This problem could be controlled by proper drainage design and construction and efficient maintenance activities of drainage systems.
item: Thesis-Abstract
Environmental changes in irrigation and flood control schemes: a case study of Gin Ganga regulation project
Senewiratne, LW; Wijesekera, NTS
Gin River which is 113km long is situated in the South-West of Sri Lanka. Its lower basin has a flood history, which usually destroys about 6000ha of paddy and 3000ha of highland crops. The South-West of Sri Lanka receives an annual average rainfall of 2600mm. Gin River flood control project was completed in 1980. Lower basin of the catchment was protected by electric pumps in 3000ha and gravity drainage was newly provided for 1740ha of Holuwagoda Tract. The project occupied 250ha in between flood bunds in the flood corridor on each river bank. 78ha of paddy lands in the upper catchment were subjected to added flooding and backwater effect after the project. New 800ha of marshy lands were converted in to paddy lands. Normal drainage was provided during non-flood periods. The Project is presently maintained by Irrigation Department. Many paddy tracts were abandoned after the drought in 1992. Many environmental issues have contributed to present situation. The achievements and adverse effects are studied to identify the needs in planning and designs of flood control projects. The objectives of this study could be listed as: 1) Identification of environmental issues prior to the implementation of the irrigation and flood control project. 2) Identification of present environmental issues after the completion of the irrigation and flood control project. 3) Identifying the environmental issues, which require to be considered in case of irrigation and flood control projects. In order to carry out this as a case study, Gin Ganga Regulation Project (GRP) was selected as the project area. 1 Literature survey identified many environmental issues and initial site visits were used to compile all possible issues related to the project area. The issues were separated into processes and were summarised for analysis. Environmental changes due to the project were assessed using these issues. Assessment Site visits were carried out to assess the changes in selected locations. Significant issues were listed and micro analysis was done for every locality of the project using a questionnaire. Verification was done using collected data. The main achievements of GRP are, an increase in land value (150%) and infrastructure development (28%). The social processes are improved due to this project. The land use for rice was improved initially and two seasons per annum were properly cultivated. After 15 years some areas were abandoned due to low income. Some areas were rejected as planned by the project in the unprotected area. Some areas can be cultivated after desilting of canals. Soil subsidence has led to abandoning of some areas. Anticipated targets were reduced by abandoning of lower Holuwagoda tract. Soil subsidence has caused waterlogging in this area. Ganegama lower tract has lost cultivation due to subsidence. An overall assessment 84% of land use was retained for paddy under GRP. If the project was not effective this value will be reduced to 50% as in Bentara Dedduwa Scheme. 2
item: Thesis-Abstract
Environmental impacts of proposed Baddegedara impounding reservoir
De silva, PYD; Ratnayake, N
This research study, "Environment Impacts of Proposed Baddegedara Impounding Reservoir" was conducted in relation with the feasibility study for water supply and sewerage for Koggala Export Processing Zone and the surrounding license Zone.The project area consist of Talpe, Habaraduwa, Koggala EPZ and Coastal belt. Ahangama, Dikkubura and Imanduwa. People living in the area excluding Koggala EPZ have to depend on individual water sources. The majority of the population depend on ground water drawn from shallow dug wells. The main complaint of people living along the coast in the project area regarding the water quality of their dug wells in salinity. Most of these wells are shallow and not covered or protected. Water obtained from these wells is therefore at high risk to be polluted with organic matter.Study was conducted by having field surveys. When selecting a source for the project area whenever possible first choise was given to ground water which requires the least treatment. But the test drilling programme shows that it is impossible to get total water requirement by ground water itself. Therefore we have to go for a surface water source close to the project area.Proposed impounding reservoir at Baddegedera is located nearest to the project area. Reservoir catchment is the upper most reign of a tributary of Polwatta ganga which meets the main river about 2 Km upstream of Kananka. This catchment is located near to the catchment of Hiyare impounding reservoir which is presently supplying part of water to the Galle Municipality. Environment Impacts were assessed by using a matrix called Environment interaction matrix. In this method a list of all potential impacts of the project were prepared and each individual impact was assessed. The matrix was analyzed by using the Battle's environment evaluation system. In this method the weights of the parameters were assigned depending on the relative importance of the parameters. Value function for the variation of environmental quality index with the change in each of the environmental parameter had to be determined. The environmental quality (e.q.) index with project and the e.q. index without project were evaluated for each environment parameter. Then the environment impact unit was obtained by getting the product of the relative weight of the parameter and the e.q. index. In this method positive net change of product means beneficial impacts whereas negative product means adverse impacts. The topography of the area does not lend itself to the fashioning of a deep lake. According to past studies done by various people the ideal wildlife lake is shallow with gently slopping shore. This type of situation could be expected from the proposed impoundment. These natural qualities of the habitat could be further augmented by various management techniques such as the restriction of the area of impoundment and catchment.
item: Thesis-Abstract
Environmental noise levels in the area of authority of G.C.E.C. at Katunayake investment promotion zone
Perera, SEJ; Ponnambalam, M
Katunayake has been a hive of activity ever since the International Airport was opened several years ago. With the advent of the Investment Promotion Zone and the concept of an open economy, Katunayake has today become one of the busiest areas in Sri Lanka. One of the prices it has to pay for carrying out increasing activity is the ever-increasing noise pollution. It is easy to identify the three main sources of noise pollution in the area of authority of Greater Colombo Economic Commission at Katunayake Investment Promotion Zone, ie its factories, the Airport and the road traffic. This study was carried out at an opportune time to assess environmental exposure to noise arising out of the above sources. Its findings have confirmed that noise is a problem of immense magnitude in this area and that everyone concerned cannot afford to ignore it without paying a dear price for it.
item: Thesis-Abstract
Evaluation of public participation and methodologies adopted in environmental impact assessment process in Sri Lanka
Weerakkody, NC; Wijesekera, NTS
"Environment" and "Development" are interdependent and mutually reinforcing each other. The ultimate goal and purpose of both environment and development policies is betterment, improvement and the enhancement of the quality of life. Exploitation of natural and human resources should be planned carefully to ensure a sustainable development. In order to ensure a sustainable development, Western Countries have introduced a planning tool, i.e. Environmental Impact Assessment process to assess the impacts of any development project to its environment. Mitigatory measures also suggested in the EIA report to minimize the negative impacts. Public involvement is one of the significant and important events in the Environmental Impact Assessment Process. This process expects to ensure that the environmental concerns are incorporated into the project. In order to fulfill this requirement, it is necessary to seek public participation throughout the project development process. The ETA process has built-in openings for public participation. Therefore, it needs to investigate whether such participation has been effective or needs improvement to ensure that the development works are not slowed down. The main objective of the study is to identity the present level of public participation in IEE/EIA projects and the methodologies used for development projects. To achieve this objective, thirteen IEEs and fifteen EIAs were selected. The respective IEE/EIA reports and administrative files were analyzed. After analyzing the IEE/EIA reports and files, public participation was looked at in different aspects, i.e. the sectors participated, the stages in the EIA process, the issues raised by the public in their comments and the methodologies adopted in the EIA process. These aspects were studies under different project types, i.e. Mainly IEE/EIA, Effluent generating/Effluent non-generating and localized/spatially distributed projects. Accordingly, general public participation on TEE project is very low compared that with the EIA projects. Study reveals general public participation on IEE projects is 2% and in EIA projects 98%. The overall public response on development projects are fairly low. Data reveals the maximum overall participation on development projects is only 42%. Also, the public is highly concern on social impacts specially in EIA projects, Effluent non-generating projects and spatially distributed projects.
item: Thesis-Abstract
Feasibility study of increasing the rate of digestion in anaerobic digesters
Jayasuriya, JAAD; Pathinather, S; Thillekeratne, YR
The anaerobic digestion of vegetable garbage, is quite slow, with retention times of 80- 100 days. Because of these slow rates of digestion, reaction vessels needed, are quite large. Research clearly needs to concentrate on increasing the rate of the process and decreasing the reactor volumes required. in commercial applications. In this study a literature survey was carried out to find out the possible ways of increasing the rate of anaerobic digestion and later some laboratory work was carried out in order to verify some of the findings of the literature survey. Literature survey showed that for the anaerobic digestion to be efficient the environment inside the reactor should be strictly anaerobic; the value of pH should be between 7 and 8. the feedstock should be biodegradable and should contain enough seed bacteria; the carbon to nitrogen ratio ( CIN) of the feed should be between 20 and 30. Furthermore literature shows that anaerobic digestion can occur in three different temperature ranges due to the activity made by three different groups of bacteria. Cryophylic range is between 10°C and 20°C: Mesophilic range is between 30°C to 40°C; and Thermophilic range is between 4SoC and 60°C According to the literature thermophilic bacteria are most efficient and they can digest vegetable garbage within a period of 10 days. Laboratory experiments also confirmed that within the thermophilic range, if the other environmental parameters are fulfilled. a mixture of vegetable garbage is anaerobically digested in a period of 10 days Laboratory experiments confirmed that application of enrichment culture also enhances the performance of anaerobic digesters.
item: Thesis-Abstract
Feasibility study on waste oil disposal in cement kilns for Sri Lanka
(2014-06-06) Thiruchelvam, AT; De Alwis, AP
1. Main Objective To study the feasibility of disposing the waste oil in the existing Puttalam Cement Kilns for Sri Lanka. To achieve this objective, the current situation in terms of technologies (manufacturing, fuel firing, process control, dust emission equipment and performance, etc.) of Puttalam Cement and the financial viability was evaluated. 2. Introduction Disposing of waste oil in Cement Kilns will give three fold benefits: getting rid of waste oil, almost without any residue, complete energy recovery which contribute to the economy of a country and special disposal facilities are not needed as an existing facility is utilised High flame temperatures and the nature of the product make cement kilns attractive for the destruction of a variety of hazardous organic materials. With proper management, kilns constitute a much less costly alternative to dedicated waste incinerators. Tests by USEPA and others have demonstrated that destruction of organic compounds including, PCBs and organochlorine and organophosphorus pesticides, equals or surpasses that achieved in hazardous waste incinerators tl1at operate at l wer temperatures. Many toxic metallic compounds can also be burned in cement kilns in quantities that are small enough not to adversely affect product quality or safety, since they are bonded to the clinker and become part of the product. 3. Waste Oil It refers to lubricating oils, hydraulic, transmission & heat transfer fluids and insulants that have gone tl1rough their intended use cycle and must be either disposed of or treated and re-used. In this thesis, waste oil from automotive transport sector is only considered. Other transport (aviation and maritime) sector and spent industrial oils are not included here as waste oil since these oils are contaminated with unknown pollutants. 4. Waste Oil Generation and Properties in Sri lanka A pilot survey was carried out to estimate the waste oil generation and centrally collectable amount. According to tl1e survey results, in 1999 around 24,000 - 27,000 ton waste oil was generated by automotive transport sector in Sri Lanka. However, tl1e known collectable amount is 4,500 (about 18% of the generated amount) while the estimated amount is around 17,400 ton per year in 1999 as given in Table 23. With time, awareness, incentives, and enforcement of regulation, the estimated amount can be collected. The laboratory test results show that our waste oil property is within the literature values in terms of physical property and tl1e contaminants such as heavy metals. However, it is interesting to note tl1at tl1e ASTM distillation curve of tl1e waste oil distillate resembles kerosene oil and the quantity distilled also only 63%. This shows that the best option in World of waste oil disposal by rerefining back to lube base may not be possible in Sri Lanka and therefore, tl1e best option for our waste oil is using as alternate fuel which is well supported by tl1e high calorific test results (> 44,000 kJ/kg). However, with the limited number of tests it is difficult to come to a firm conclusion. This is only an indication. 5. Puttalam Cement Cement is manufactured by grinding an artificial rock called "clinker" very finely (to a few microns) mixing with a small amount of gypsum (approximately 4%). Clinker is produced by heating limestone (77%) and some other ingredients (23%) to around 1450°C in a kiln. At Puttalam Cement Factory, there are two identical rotary kilns. The length of a kiln is 54 m. The burner of the kilns were change recently by Rotaflam kiln burner which has an additional jacket tube for a waste oil gun. A complete actual material balance could not be done with the current on line measured and recorded data at Puttalam Cement. Therefore, some assumptions were made using the equipment specifications and international norms 1n domg the material balance. The average amount.......x·ffffff_·raw materials used for one
item: Thesis-Abstract
Improving the methodologies adopted for assessment of environmental and social impacts of mini hydro power projects
Rohana, RPDI; Manathunge, JMA
This Research is aim to look at the environmental impacts related to Mini hydro projects in Sri Lanka and to determine the available methodologies for identification of Major Environmental Impacts and the options to mitigate the impacts or avoid impacts. It is also tried to look at the monitoring process conducted by project Monitoring Committee during the implementation of mitigations and the public participation in the IEE/EIA process. In this research, twelve mini hydro projects were studies by collecting data from field studies and IEE reports by focusing Environmental Methodologies used and the Monitoring Process of the Projects. The collected data from the twelve Mini Hydro Power Projects are analyzed and discussed comparatively to standards and guidelines in Sri Lanka.. The research observed that the exact gap between predicted impact and the implemented impact is cannot be analysis. In addition, it was observed that the IEE report does not mentioned methods of impact identification. This is a weakness of submission IEE report as well as Term of Reference (TOR). TOR should be laid down the condition that the method of impact identification should be included in the IEE report. All the projects taken to research have neglected the monitoring process and which is an important part of IEE and EIA. The Environmental Monitoring process is not compressive and PP had violated mitigation as well as the conditions stipulated by the PAA. Hence, Monitoring process must be improved to implement of Predicted mitigations satisfactorily. The IEE reports of Sri Lanka are not in unique order, similar to other countries like India. Sri Lanka must have proper stand guideline to be followed by Mini hydro Project As per the studies, the Mini Hydro Projects have to face challenge such as heavy flood, blasting hazards, Landslides and soil erosion. These challenges can be overcome by proper planning and management.
item: Thesis-Full-text
Investigation of micro-climatic features (vegetation) affecting the indoor air quality in suburb cities of Colombo
Premachandra, DSPRD; Jayasinghe, C
Considerable number of studies show a favourable impact of vegetation and an adverse impact of synthetic built environment on urban micro-climates. Despite these findings, people eradicate these favourable micro-climatic features for built purposes. In the past few decades suburbs of the Colombo, the capital city of Sri Lanka, was subjected to a rapid development mainly for residential purposes. As a result, paddy fields, marshy lands and large tree canopies have been converted to a built environment with scattered green patches. This study was aimed at determination of the impact of micro-climatic features on air quality and thermal comfort. Air quality investigations were carried out in five residential buildings which were selected based on the surrounding micro-climatic features. Indoor concentrations of CO2, NO2, PM2.5, CO, VOC, temperature, relative humidity and wind speeds were measured during the day time from 9.00 AM to 4.00 PM in each sample building. The results were checked against the air quality standards and an attempt has been made to establish a relationship with micro-climatic features. The results showed that the air quality in suburbs is still in the acceptable range except for peaking of PM2.5 concentration beyond the threshold time to time. Lower levels of temperature and CO2 concentration were observed with good micro-climatic features. Decrease of PM2.5 concentration was also detected with the increase of distance to the main road and vegetation cover. These findings will benefit the township planning in terms of preserving the air quality and thermal comfort levels in suburbs.
item: Thesis-Abstract
Management of unaccounted for water in greater Colombo water supply system
Chandrasekera, HJVC; Ratnayake, N
water losses in water supply systems is a common phenomenon eperienced by water supply facilities all over the world.Unaccounted For Water (UFW) is the difference between the uantity of water produced and the quantity of water consumed,in water supply system.The term "Non Revenue Water" (NRW) is used to define the difference between the quantity of water produced and the quantity of water which brings in revenue to the Water Authority and sometimes used instead of UFW.UFW in a water supply system cannot be eradicated but could be minimised and maintained at a low level, by proper management operations and controls in the system.In this report, the author studies and analyses in depth, the problem of UFW in Greater Colombo distribution system with reference to the available figures of UFW and its components.A detailed classification of UFW is given in Fig. 1.1 and the situation in other countries also are outlined. A literature review was carried out on methods to manage the major components of UFW, with special concern to the Greater Colombo System.Available literature on performance of water meters were also reviewed. Also the economics of management of UFW is discussed under theoretical considerations. A theoretical study was done on active leakage control and the active leakage control becomes passive lekage control and level of leak at which the economical was determined. Also certain indices were derived to calculate the UFW and its components, with the availability of refined field data in future. In the field programme, field methods to control UFW were tried out. An insertion meter pipe flow testing was done to verify as a sample, the accuracy of readable production bulk meter and the reading was found to be satisfactory. A leak repair recording format was designed to be implemented in Greater Colombo maintenance offices. The characteristics and benefits of this format is explained in section 3.2 and discussed in the discussion. A test was done to verify the effect of throttling of stand posts. 5 stand posts were metered and throttled. This test yielded extremely satisfactory results in the field. The costing of this proposal was done under the discussion. A minimum night flow test was carried out as a trial on a selected and isolated sample of distribution system and satisfactory results were gained on the selected stretch of distribution. Sample testing of water meters were done on two batches of 1/2" water meters viz, turbine meters and volumetric meters. On the results obtained, it was suggested to replace turbine meters in the system and a costing calculation was done in the Chapter 4. Author concludes that the throttling of standposts is one of the most effective means to reduce NRW in G/C. Also turbine meter replacement and caretaker system were shown to be effective means. Author further emphasizes the importance of highest attention on bulk production meters and also concludes that MNF test could be regarded as a suitable baseline to monitor UFW. Author recommends on further study on meter replacement periods, action plan to control illegal consumption, and setting out guidelines on LR, LDR and PRo Also emphasis is made on the importance of studying on modifications to be done on the present distribution system and future distribution systems in order to facilitate reducing and easy control of UFW.

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