vii PREFACE The International Conference on Advances in Engineering and Technology (AET2006) was a monumental event in the engineering and scientific fraternity not only from the African continent but also from the larger world, both technologically advanced and still developing. The Conference succeeded in bringing together to Uganda, affectionately called "The Pearl of Africa", scores of some of the world-famous scientists and engineers to share knowledge on recent advances in engineering and technology for the common good of humanity in a world that is no more than a global village. These Proceedings are a compilation of quality papers that were presented at the AET2006 Conference held in Entebbe, Uganda, from 61 th to 91 th July, 2006. The papers cover a range of fields, representing a diversity of technological advances that have been registered in the last few decades of human civilization and development. The general areas covered range from advances in construction and industrial materials and methods to manufacturing processes; from advances in architectural concepts to energy efficient systems; from advances in geographical information systems to telecommunications, to mention but a few. The presentations are undoubtedly a pointer to more such advances that will continue to unfold in the coming years and decades to meet the ever growing demands and challenges of human survival in the face of diminishing natural resources for an ever-increasing population. The timing of the Conference could not have been more appropriate: it is at the time when most of Africa is facing an unprecedented energy crisis engendered by a combination of factors, namely drought (resulting in the recession of water reservoir levels), accelerated industrialization that outstrips available power gen- eration, inadequate planning, poor economies, etc. We think the AET2006 Conference has presented practical ideas for solving this and many other problems that face the peo- ples of Africa and other continents. The editors of the Proceedings, on behalf of the AET2006 Conference Organising Com- mittee, extend their thanks to the authors for accepting to share their knowledge in these Proceedings. All the experts who peer-reviewed the papers are most thanked for ensuring that quality material was published. The guidance given by the members of the Interna- tional Scientific Advisory Board is greatly acknowledged. The Sponsoring Organisations are most sincerely thanked for making it possible for the Conference and its Proceedings to be realized. The staff of the Faculty of Technology, Makerere University, and particu- larly the Dean, Dr. Barnabas Nawangwe, is given special thanks for providing an envi- ronment that was conducive for the smooth accomplishment of the editorial work. Fi- nally, the editors thank their families for the cooperation and support extended to them. J. A. Mwakali G. Taban-Wani xvii INTERNATIONAL CONFERENCE ON ADVANCES IN ENGINEERING AND TECHNOLOGY (AET 2006) Local Organising Committee Prof. Jackson .A Mwakali (Chairman), Makerere University Dr. Gyavira Taban-Wani (Secretary), Makerere University Dr. B. Nawangwe, Makerere University Prof. E. Lugujjo, ererekaM ytisrevinU Prof. S.S. Tickodri-Togboa, Makerere University Dr. Mackay E. Okure, Makerere University Dr. Albert I. Rugumayo, Ministry of Energy and Mineral Development International Scientific Advisory Board Prof. Adekunle Olusola Adeyeye, National University of Singapore Prof. Ampadu, National University of eropagniS Prof. Gerhard ,xaB ytisrevinU of ,alasppU nedewS Prof. Mark Bradford, University of New South Whales, Australia Prof. Stephanie Burton, University of Cape Town, Cape Town, South Africa Prof. R.L. Carter, Department of Electrical Engineering, University of Texas at Arlington, USA Prof. David Dewar, University of Cape Town, South Africa Prof. P. Dowling, University of Surrey, UK .forP Christopher ,slraE ytisrevinU of ,hgrubsttiP ASU Prof. .N EI-Shemy, tnemtrapeD of scitamoeG ,gnireenignE ytisrevinU of ,yraglaC ,atreblA adanaC Prof. Tore Haavaldsen, NTNU, Norway Prof. Bengt Hansson, Lurid University, Sweden Prof. H.K. Higenyi, Department of Mechanical Engineering, Faculty of Technology, Makerere University Kampala, Uganda Prof. Peter .B Idowu, Penn State Harrisburg, Pennsylvania, USA Prof. N.M. Ijumba, University of Durban-Westville, South Africa Prof. Ulf Isaacson, Royal Technical University, Stockholm, Sweden Prof. Geofrey R. John, University of Dar-es-Salaam, Tanzania Prof. Rolf Johansson, Royal Technical University, Stockholm, Sweden Prof H~kan Johnson, Swedish Agricultural University, Uppsala, Sweden, Prof. V.B.A. Kasangaki, Uganda Institute of Communications Technology, Kampala, Uganda Prof. G. Ngirane-Katashaya, Department of Civil Engineering, Faculty of Technology, Makerere University, Kampala, Uganda Prof. Badru M. Kiggudu, Department of Civil Engineering, Faculty of Technology, Makerere University, Kampala, Uganda Dr. M.M. Kissaka, University of Dar-es-Salaam, Tanzania Era. Prof. Bj6rn Kjelstr6m, Royal Technical University, Stockholm, Sweden Prof. Jan-Ming Ko, Faculty of Construction and Land Use, Hong Kong Polytechnic University, Hong Kong, China Era. Prof. W.B. Kraetzig- Ruhr University Bochun, Germany Prof. R.W. ,siweL ytisrevinU of ,selaW ,aesnawS UK xviii Prof. Beda Mutagahywa, University of Dar-es-Salaam, Tanzania Prof. Burton M. L. Mwamilla, University of Dar-es-Salaam, Tanzania Dr. E. Mwangi, Department of Electrical Engineering, University of Nairobi, Kenya Dr. Mai ,agebulaN dlroW ,knaB ,alapmaK adnagU .forP Jo ,oreN ytisrevinU of epaC ,nwoT htuoS acirfA Prof. D.A. Nethercot, Imperial College of Science, Technology & Medicine, UK Dr Catharina Nord, Royal Institute of Technology, Stockholm, Sweden Prof. A. Noureldin, Department of Electrical & Computer Engineering, Royal Military College of Canada, Kingston, Ontario, Canada Prof. Rudolfo Palabazer, ytisrevinU of ,otnerT ylatI Prof. G.N. Pande, University of Wales, Swansea, UK Prof. G. A. Parke, University of Surrey, UK Prof. Petter Pilesj~, University of Lund, Sweden Dr. Pereira da Silva, Faculty of Technology, Makerere University, Kampala, Uganda Prof. legiN John Smith, ytisrevinU of ,sdeeL UK Prof. Lennart Soder, Royal Institute of Technology, Stockholm, Sweden Prof. Orjan Svane, Royal Institute of Technology, Stockholm, Sweden Prof. Sven Thelandersson, Lurid University, Sweden Prof. Roger Thunvik, Royal Institute of Technology, Stockholm, Sweden Prof. Lena Trojer, Blekinge Institute of Technology, Sweden Prof. F.F. Tusubira, Directorate of ICT Support, Makerere University, Kampala, Uganda .forP Brian ,yU ytisrevinU of ,gnognolloW ailartsuA Prof. Dick Urban Vestbro, Royal Institute of Technology, Stockholm, Sweden Prof. A. Zingoni, University of Cape Town, South Africa gnirosnopS dna gnitroppuS snoitasinagrO Makerere University NUFU Sida/SAREC Ministry of Works, Housing and Communications Uganda Institution of Professional Engineers Construction Review Fontaine, Kenner & Hoyer CHAPTER ONE KEYNOTE PAPERS WATER QUALITY MANAGEMENT IN RIVERS AND LAKES T. A Fontaine, Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, ,DS ASU .S .J Kenner, Department of Civil and Environmental Engineering, South Dakota School of Mines and Technology, Rapid City, ,DS ASU D. Hoyer, Water and Natural Resources, RESPEC, Rapid City, ,DS ASU ABSTRACT An approach for national water quality management is illustrated based on the 1972 Clean Water Act in the United States. Beneficial uses are assigned to each stream and lake. Water quality standards are developed to support these beneficial uses. A data collection program is used to make periodic evaluation of the quality of water bodies in each state. A bi-annual listing of all impaired water is required, with a schedule for investigations to determine causes of pollution and to develop plans to restore desired water quality. The approach is illustrated using recent water quality investigations of two rivers in the Great Plains Region of the United States. Keywords: water quality management, total maximum daily load, pollution. 1.0 INTRODUCTION Water quality is related to the physical, chemical and biological characteristics of a stream, lake or groundwater system. Once the water quality of a water body is compromised, sig- nificant effort and cost are required to remediate the contamination. Protecting and improv- ing the quality of water bodies enhances human health, agricultural production, ecosystem health, and commerce. Maintaining adequate water quality requires coordinated national policy and oversight of state and local water quality management. International Conference on Advances in Engineering and Technology A critical component of water quality management in the USA is the 1972 Federal Clean Water Act, which established additional rules, strategies, and funding to protect and improve water quality of streams and lakes. The US Environmental Protection Agency (EPA) is the federal administrator of the program. Water quality management of specific water bodies (rivers, lakes, and estuaries) is delegated to state and local governments that are required to meet the federal regulations. Key components of this process include (1) definition of bene- ficial uses for each water body, (2) assigning water quality standards that support the benefi- cial uses, (3) an antidegredation policy, and (4) continual water quality monitoring. Each state must submit a list of impaired waters to the EPA every 2 years. The most com- mon reasons for these waters to be impaired include pollution related to sediments, patho- gens, nutrients, metals, and low dissolved oxygen. For each water body on the list, a plan is required for improving the polluted water resource. A fundamental tool in this plan is the development of a total maximum daily load (TMDL). For a specific river or lake, the TMDL includes data collection and a study of the water quality process, evaluation of current sources of pollution, and a management plan to restore the system to meet the water quality standards. These aspects of water quality management are described in the remainder of this paper. The concepts of beneficial uses, water quality standards, the antidegredation policy, the list- ing of impaired water bodies, and the development of a TMDL are discussed. Case studies from recent research in South Dakota are then used to illustrate the development of a TMDL. 2.0 BENEFICIAL USES AND WATER QUALITY STANDARDS The State of South Dakota has designated 11 beneficial uses for surface waters: (cid:12)9 Domestic water supply (cid:12)9 Coldwater permanent fish life propagation (cid:12)9 Coldwater marginal fish life propagation (cid:12)9 Warmwater permanent fish life propagation (cid:12)9 Warmwater semi-permanent fish life propagation (cid:12)9 Warmwater marginal fish life propagation (cid:12)9 Immersion recreation (cid:12)9 Limited contact recreation (cid:12)9 Fish and wildlife propagation, recreation, and stock watering (cid:12)9 Irrigation (cid:12)9 Commerce and industry The EPA has developed standards for various beneficial uses. Each state can apply the EPA standards, or establish their own state standards as long as they equal or exceed the EPA standards. Examples of parameters used for standards for general uses include total dis- Fontaine, Kenner & Hoyer solved solids, pH, water temperature, dissolved oxygen, unionized ammonia, and fecal coli- form. Water quality standards for metals and toxic pollutants may be applied in special cases. Waters for fish propagation primarily involve parameters for dissolved oxygen, un- ionized ammonia, water temperature, pH, and suspended solids. Standards are either for "daily maximum", or acute values or "monthly average" or chronic values (an average of at least 3 samples during a 30-day period). Additional standards for lakes include visible pol- lutants, taste- and odor- producing materials, and nuisance aquatic life. The trophic status of a lake is assessed with a Trophic State Index (TSI) based on measures of water transpar- ency, Chlorophyll-a, and total phosphorus. Maximum values of the TS! allowed as support- ing beneficial uses of lakes range from 45 to 65 across the state. The detailed numeric stan- dards for surface water quality in South Dakota are described in South Dakota Department of Environment and Natural Resources (2004). 3.0 LISTING OF IMPAIRED WATER BODIES Section 303d of the Federal Clean Water Act requires each state to identify waters failing to meet water quality standards, and to submit a list to the EPA of these waters and a schedule for developing a total maximum daily load (TMDL). A TMDL represents the amount of pollution that a waterbody can receive and still maintain the water quality standards for the associated beneficial use. The list of impaired waters (the "303d list") is required every 2 years. Examples of the most frequent reasons for listing waters across the USA are: (1) nu- trients, sediments, low dissolved oxygen, and pH for lakes; and (2) sediments, metals, pathogens, and nutrients for streams. The number of waterbodies on the 303d list for South Dakota has been about 170 for the past 8 years. The decision to place a waterbody on the 303d list can be based on existing data that docu- ment the impaired water quality, or on modeling that indicates failure to meet water quality standards. A waterbody that receives discharges from certain point sources can also be listed when the point source loads could impair the water quality. If existing data are used to evaluate whether or not a water should be listed, the following criteria apply: (1) 20 water quality samples of a specific parameter are required over the last 5 years; (2) over 10% of the samples must exceed the water quality standard for that pa- rameter; and (3) the data must meet certain quality assurance requirements. 4.0 REMEDIATION STRATEGIES For each water placed on the 303d list, a strategy for improving the water quality so that the standards are met is required. The development and implementation of a TMDL is the most common approach for remediation strategies. A TMDL is calculated as the sum of individ- ual waste load allocations for point sources, and load allocations for nonpoint sources and for natural background sources, that are necessary to achieve compliance with applicable surface water quality standards. The units of the TMDL can be mass per day or toxicity per International Conference on Advances in Engineering and Technology day for example, but not concentration. The waste load allocation involves point sources, which are regulated by the National Pollution Discharge Elimination System program (NPDES: see South Dakota Department of Environment and Natural Resources, (2004)). A point source permit must be renewed every 5 years. Examples of load allocations (nonpoint sources) include agricultural runoff and stormwater runoff from developed areas. Natural background loads involve pollution from non-human sources. Examples include high sus- pended solids in watersheds with severe erosion due to natural soil conditions, high fecal coliform concentrations due to wildlife, and elevated streamwater temperatures due to natu- ral conditions. A margin of safety is included in the TMDL to account for the uncertainty in the link between the daily pollutant load and the resulting water quality in the stream or lake. The process of developing and implementing a TMDL usually involves a data collection phase, the development of proposed best management practices (BMPs), and an implemen- tation and funding strategy. A water quality monitoring program may be required to gener- ate data to define the watershed hydrologic system, measure water quality parameters, and identify the sources of pollution. A computer simulation model may be used to calculate the TMDL required for the stream or lake to meet the water quality standards for the beneficial uses involved. Once the TMDL is known, various management actions are evaluated for their effectiveness in decreasing the pollutant loads to the point where the water quality standards are met. Point source loads are managed through the NPDES permit system. Man- agement of nonpoint sources requires cooperation among federal, state, and local agencies, business enterprises, and private landowners. Examples of activities by individuals, corpora- tions, and government agencies that generate nonpoint pollution sources include agriculture (livestock and crop production), timber harvesting, construction, and mining. Federal and state funding can be applied for to promote voluntary participation in best management practices (BMPs) to reduce water pollution related to these activities. Once the implementation phase of the TMDL begins, water quality monitoring continues on a regular basis to measure the impact on water quality of the selected BMPs. The state is allowed 31 years from the time the specific river or lake is placed on the 303d list to develop the TMDL, complete the implementation, and restore the water to the standards required to support the beneficial uses of that water. A final aspect of the water quality management program is an antidegredation policy. Antidegradation applies to water bodies with water quality that is better than the beneficial use criteria. Reduction of water quality in high quality water bodies requires economic and social justification. In any case, beneficial use criteria must always be met. Establishing desired beneficial uses for every surface water body, and the associated stan- dards required to support those uses, provides the framework to protect and improve the Fontaine, Kenner & Hoyer water quality of a country so that all benefit. The process of routine collection of water qual- ity data provides the information needed to identify impaired waters, place them on the 303d list, and to define a plan to develop and implement a strategy for restoring the desired level of water quality. The following case studies illustrate some of the procedures and issues that are often involved in this process. 5.0 SPRING CREEK Spring Creek is located on the eastern side of the Black Hills of South Dakota. The portion of Spring Creek involved in this project has a drainage area of 327km 2 at the outflow gage at 43~ and 103029 , 18". The annual mean discharge is 0.62m3/s (1991 - 2004), maxi- mum daily mean discharge of record is 14.9m3/s, and minimum daily mean discharge is 0.0m3/s. The average annual precipitation is 56cm and the land cover is Ponderosa Pine for- est. The beneficial uses of this section of Spring Creek are (1) cold-water permanent fish life propagation, (2) immersion recreation, (3) limited-contact recreation, and (4) fish, wildlife propagation, recreation, and stock watering. Spring Creek was placed on the 303d list and scheduled for TMDL development because the standard for fecal coliform in immersion recreation waters was exceeded. Fecal coliform bac- teria are present in the digestive systems of warm blooded animals, and therefore serve as an indicator that the receiving water has been contaminated by fecal material. Symptoms of ex- posure in humans include cramps, nausea, diarrhea, and headaches. The objective of the project was to support the development of the TMDL using a water quality monitoring program and a computer simulation program (Schwickerath et al, (2005)). Data from the water quality monitoring program helped identify the sources of fecal coliform and measure the current loads. The simulation model provided insight into the relation of the sources to the loads exceeding the standards for the immersion recreation use, and was used to estimate the reduction of pollution levels resulting from various water quality management activities in the watershed. 5.1 Monitoring Program Fourteen monitoring sites were selected in the study area: 9 on the main channel of Spring Creek, 2 on Palmer Gulch Tributary, 2 on Newton Fork Tributary, and 1 on Sunday Gulch Tributary. Monthly grab samples were collected for 51 months at all 14 sites, and samples during storm-runoff events were collected at 6 stations. The storm event samples were col- lected over a 12 to 24 hour period on a flow-weighted basis. Streamflow measurements were taken periodically during the 51 month study to establish stage-discharge ratings at each sta- tion. A quality assurance program using field blanks and field replicates every 10 samples was used to measure the reliability of the data. International Conference on Advances in Engineering and Technology Samples were analyzed for fecal coliform, total suspended solids, pH, temperature, ammo- nia, and dissolved oxygen. The criteria for fecal coliform in immersion contact recreation has two standards: (1) the geometric mean of at least 5 samples collected during a 30 day period must not exceed 200 colony-forming units (cfu) per 100mL; or (2) a maximum of 400cfu per 100mL in a single sample. The water is considered impaired if either standard is exceeded by more than 10% of the samples. The water quality standards for the other rele- vant parameters were: total suspended solids less than 35 mg/L (daily maximum sample), pH between 6.6 and 8.6, water temperature of 18.3~ or less, and at least 6 mg/L dissolved oxygen. The standard for ammonia depends on the temperature and pH at the time of sam- pling. The fecal coliform standard was exceeded in 17% of the samples from the main channel of Spring Creek, 30% of samples from Palmer Gulch Tributary, and 13% of samples from Sunday Gulch Tributary. More than 10% of samples from Palmer Gulch Tributary also exceeded standards for total suspended solids (22% exceeded), pH (11% exceeded), and ammonia (11% exceeded). Fourteen percent of samples in Newton Fork Tributary exceeded the temperature standard. These results confirm that a TMDL for fecal coliform bacteria is required for this section of Spring Creek. The results also indicate that Palmer Gulch Tribu- tary should be considered for an independent listing on the 303d list of impaired water, and that additional monitoring is needed to investigate temperature conditions on Newton Fork Tributary. Additional sampling was used to estimate the distribution of fecal contamination coming from humans and animals. A DNA fingerprinting analysis called ribotyping can indicate the source of fecal coliforms. Results of the initial ribotyping samples suggest that 35% of the fecal coliform in Spring Creek originates from humans, with the other 65% coming from livestock (cattle) and wildlife in the catchment. This information is used to develop reme- diation options to help Spring Creek meet the water quality standard. For example, potential sources of human coliform include leaking sewer systems, leaking treatment lagoons at Hill City (a town of 780 people in the center of the study area), and failed septic systems. 5.2 Simulation Modeling Analysis The Better Assessment Science Integrating Point and Nonpoint Sources (BASINS) and the HSPF simulation models were used to investigate the impact of various remediation activi- ties on the coliform contamination in Spring Creek (US Environmental Protection Agency (2001), Bicknell et al, (2000)). These models provide comprehensive simulation of the hy- drology, channel processes, and contaminant processes on a continuous basis. Field data were used to calibrate and validate the model. The effectiveness of various best management practices (BMPs) for remediating pollution can be simulated with the models. The nonpoint sources of fecal coliform contamination in Fontaine, Kenner & Hoyer Spring Creek include humans and urban runoff, runoff from agricultural land and livestock, and wildlife. Human and urban runoff sources include leaks from septic systems of individ- ual homes, sewer pipes, and treatment lagoons, and animal feces. Livestock (primarily cat- tie in this watershed) generates waste in concentrated compounds near farms during cold months and across widely distributed areas of the catchment during the warmer open range season. Fecal coliforms from livestock are deposited near, and easily washed into, streams in areas where no fences exist along the riparian zones. Examples of BMPs applied in the modeling analysis included improving failed septic sys- tems, leaking sewer systems, and leaking treatment lagoons, and keeping cattle away from streams. Various combinations of these BMPs are simulated and the TMDL in Spring Creek is calculated for each scenario. Two of these scenarios were successful in reducing the TMDL to the point where the water quality in Spring Creek would be expected to support the beneficial uses. The final phase of the water quality program involves collaboration between the state envi- ronmental agency, local residents and landowners, and funding agencies to implement the effective BMPs. Water quality monitoring will continue during this period in order to meas- ure the actual impact on fecal coliform loads, and to document the point when the water quality attains the standards for the beneficial uses of Spring Creek. 6.0 WHITE RIVER The White River is located in the prairie region of southwestern South Dakota. The drainage area is 26,000kin: at the downstream boundary of the study area at 43~ and 99~ ''. The annual mean discharge is 16.2m3/s (1929 - 2004), maximum daily mean discharge of record is 1247m3/s and minimum daily mean discharge is 0.0m3/s. Suspended sediment concentrations vary widely, with maximum daily mean of 72,300mg/L and mini- mum daily mean of 1 lmg/L (for period of 1971 to 2004). Climate is semi-arid, with 41cm of rain per year and 102cm of lake evaporation per year. Land cover is rangeland and grass- land, with areas of Badlands (steep terrain with highly erodible, bare soil). The river basin has 91 streamflow gaging stations. Spring-fed baseflow provides most of the discharge in the upper portions of the drainage area. Streamflow is a combination of base- flow and storm-event runoff in the lower portions of the basin. An analysis of streamflow data and a physical habitat assessment indicated that the river basin could be divided into three sections (the upper, middle and lower reaches), each reflecting water quality character- istics related to the hydrology, geology, and land use of the section (Foreman et al (2005)) The beneficial uses for the White River are (1) warm-water semi permanent fish life propa- gation; (2) limited contact recreation; (3) fish and wildlife propagation, recreation, and stock waters; and (4) irrigation waters. The White River is listed as impaired for the use of warm-