Pan, N. Comparison of Water Quality of the Tonlé Sap River and the Mekong River

A Comparison of the Water Quality of the Tonlé Sap River and the Mekong River in Phnom PenhIB Geography HL Internal Assessment International School of Phnom Penh #1222 December 19, 2007, Cambodia By Nettra D. Pan Candidate #001222-011 Candidate Number: 001222-010 By Nettra D. Pan Word count: 2,569 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 2 of 56 GEOGRAPHY HL Cover photograph, ‘Riverviews,’ courtesy of Christopher Barlow of the Mekong River Commission during his presentation on the Mekong River. Acknowledgements Christopher Barlow, from the Mekong River Commission, for an insightful presentation on the river. Jan Willem Rosenboom, from the World Bank, for his time, detailed advice and useful information. Janette Fawcett, for teaching Geography and genuinely caring about our class, continuing to offer expert assistance after her departure from Phnom Penh. Lilo Henke, for imparting upon me the knowledge she gained in the IB Geography Diploma Programme. Robin and Erik Wilensky, for their valuable criticisms and feedback. S.J. Vermette, Ph. D., from New York State University at Buffalo Aquanaut Program, for donating water quality testing equipment to the International School of Phnom Penh (ISPP) and for helping to set up this project in the International Baccalaureate Geography program at ISPP. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 3 of 56 GEOGRAPHY HL A Comparison of the Water Quality of the Tonlé Sap River and the Mekong River in Phnom Penh IB Geography HL Internal Assessment Nettra D. Pan Candidate #001222-011 Word count: 2,499 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 4 of 56 GEOGRAPHY HL Contents Introduction _______________________________________________________________________ 6 I. General Background _____________________________________________________________________6 II. Rationale for Study______________________________________________________________________8 III. Aims of the Investigation________________________________________________________________8 IV. Hypotheses ____________________________________________________________________________8 V. Theoretical Background ________________________________________________________________10 1. 2. 3. 4. 5. 6. 8. 9. 10. 11. Dissolved Oxygen_________________________________________________________________________ 10 Fecal Coliform ___________________________________________________________________________ 10 pH ______________________________________________________________________________________ 11 Biological Oxygen Demand (BOD)___________________________________________________________ 11 Temperature Change ______________________________________________________________________ 12 Nutrients ________________________________________________________________________________ 13 Turbidity ________________________________________________________________________________ 14 Total Solids ______________________________________________________________________________ 14 Hardness ______________________________________________________________________________ 15 Other Pollutants _______________________________________________________________________ 15 Methodology______________________________________________________________________ 16 I. General Method ________________________________________________________________________16 II. Location of Sample Sites ________________________________________________________________16 III. Data Collection Methods _______________________________________________________________17 1. 2. 3. 6. Temperature _____________________________________________________________________________ 17 pH ______________________________________________________________________________________ 17 Turbidity ________________________________________________________________________________ 18 Nitrates _________________________________________________________________________________ 19 IV. Evaluation of Data Collection Methods___________________________________________________23 Results ___________________________________________________________________________ 24 I. Collected Data _________________________________________________________________________24 II. Presentation of Data ___________________________________________________________________25 III. Analysis and Evaluation of Data _________________________________________________________28 IV. Conclusion ___________________________________________________________________________32 Bibliography ______________________________________________________________________ 33 Figures and Diagrams _____________________________________________________________________34 Appendices _______________________________________________________________________ 36 Appendix 1: Tonlé Sap River’s Bi-Directional Unimodal Flow __________________________________36 Appendix 1.5: Tonlé Sap River’s River Volume _______________________________________________38 Appendix 2: Seasons of Cambodia ___________________________________________________________38 Appendix 3: The Effects of Urbanization_____________________________________________________39 Appendix 4: Heat, as an Effect of Urbanization _______________________________________________39 Appendix 5: Hard & Soft Water Explained ___________________________________________________40 Appendix 6: Complete List of Possible River Water Contaminants ______________________________41 Appendix 6.5: Length of Cambodian Seasons _________________________________________________45 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 5 of 56 GEOGRAPHY HL Appendix 7: Information about WQI ________________________________________________________46 Appendix 7.5: Improving the Precision and Accuracy of Data Collection _________________________48 Appendix 8: Turbidity_____________________________________________________________________50 Appendix: 9: % DO Saturation______________________________________________________________51 Appendix 10: Hardness Concentration _______________________________________________________51 Appendix 11: Evaluation of WQI ___________________________________________________________52 Appendix 12: Raw Data____________________________________________________________________53 Appendix 13: Standard Deviation ___________________________________________________________55 Appendix 14: Temperature_________________________________________________________________55 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 6 of 56 GEOGRAPHY HL Introduction I. General Background Every great civilization has a body of water which acts as a protective barrier between regions, or a meeting point for commerce and transportation. It is a renewable source of food, whether directly from the animals living in it, or else, indirectly, from the fertile, silt-covered grounds washed ashore during floods. From this waterway, cultures develop, supporting a myriad of lifestyles. In Cambodia, two rivers play these roles: the Tonlé Sap River and the Mekong River (Fig. 1.1.1). The lengths of these rivers are 160 km and 4880 km respectively. The Tonlé Sap River’s depth ranges from 1.0m to 4.0m, whereas the Mekong River’s depth ranges from 2.4m to 4.5m. The Mekong River flows southwards through Cambodia, from Laos, northeast of Cambodia, while the Tonlé Sap flows southwest from the Great Lake in the northwest of Cambodia, and back. In Phnom Penh, the Mekong River has a greater width than the Tonlé Sap River (Fig. 1.1.2).1 Image 1.1.1: the Tonlé Sap River (labeled ‘Sab’) and the Mekong River (labeled ‘Mekong’), in Cambodia The largest river in the world to seasonally change the direction of its flow,2 the Tonlé Sap holds great significance for Cambodians. For them, this river is the foundation of a country whose main 1 Tonlé Sap Database. http://www.sumernet.org/tonlesap/eng/news/news_detail.asp?id=59 11/02/07, Tracing the Mekong River. http://www.hawaii.edu/hga/gaw01/workshop/TracingMekongRiv.html 11/02/07 2 Appendix 1 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 7 of 56 GEOGRAPHY HL forms of livelihood rely on agriculture and fisheries. As the volume of the Tonlé Sap lake swells to nearly five times its original size (Fig. 1.1.3.), the region is flooded with 8-9 tons of sediment that birds, fish and crops feast on, which, in turn feeds most of Cambodia, helping the Great Lake yield crops at a rate of 230kg per hectare per year.3 Fig. 1.1.2: Google earth image of the Tonlé Sap River and the Mekong river at their confluence in Phnom Penh4. Fig. 1.1.3: Satellite image of Cambodia. The Tonlé Sap Lake and River have clearly expanded in the wet season. The lower Mekong River basin is significant to many other countries (Fig. 1.1.4). In particular, it provides 80% of the animal protein consumed by its 55 million inhabitants.5 Did You Know? The Mekong River Commission. http://www.mrcmekong.org/MfS/html/did_you_know.html 11/02/07 The Source of Life. Powerpoint presentation by Dr. S.J. Vermette from New York State University at Buffalo’s Aquanaut Program. 5 WWF Report: World’s Top Ten Rivers at Risk. WWF. http://assets.panda.org/downloads/worldstop10riversatriskfinalmarch13_1.pdf Date accessed 11/02/06 4 3 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 8 of 56 GEOGRAPHY HL Fig. 1.1.4: the Mekong River Basin flows through China, Myanmar, Thailand, Laos, Cambodia and Vietnam II. Rationale for Study Due to its location in Less Economically Developed Countries (LEDCs), limited study has been conducted on the Tonlé Sap and the Mekong River. An evaluation of the water quality in this unique river system during various seasons6 would be fascinating and necessary since its location indicates possible far-reaching implications for Cambodia and Asia, as a whole. III. Aims of the Investigation 1. To compare the water quality of the Tonlé Sap and Mekong River in Phnom Penh while controlling for differences between Cambodia’s wet and dry season. 2. To examine the effect of the wet and dry season on the water quality of the Tonlé Sap and Mekong River in Phnom Penh. IV. Hypotheses 1. The water quality of the Tonlé Sap is expected to be lower than that of the Mekong. The Tonlé Sap River’s proximity to Cambodia’s primate city suggests that it would be likely to receive larger amounts of sewage than the Mekong, increasing the amount of fecal coliform (FC) and nitrates 6 Appendix 2 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 9 of 56 GEOGRAPHY HL and phosphates (nutrients) and lowering the dissolved oxygen (DO) concentration of the river. Runoff from the streets and factories of Phnom Penh are more likely to contain pH-changing contaminants, compared to runoff from less developed areas around the Mekong River in Phnom Penh. The increased amount of automobile traffic in the inner city may lead to increased air pollution and therefore, acid rain, and nitrate and ammonium deposition.7 Also, heat pollution due to Phnom Penh’s greater amounts of concrete could increase the Tonlé Sap’s temperature and reduce the maximum amounts of DO saturation.8 Phnom Penh’s urbanization influences heavily weighted factors affecting Tonlé Sap’s water quality (Table 1.4.1). Table 1.4.1: Factors and weights contributing to the Water Quality Index, a standard created by the United States’ National Sanitation Foundation (NSF) to evaluate the water quality of temperate rivers. However, urbanization’s effect on the Tonlé Sap River may be considered insignificant if the Mekong River’s route through developed areas in Thailand is taken into account. Undeveloped sewerage systems closer to the Mekong River may also encourage more defecation into the river (increasing the amount of FC and nutrients and lowering the DO concentration of the Mekong River). Nevertheless, the Mekong River’s consistently large volume makes the concentration of waste products less significant in terms of water quality.9 The Tonlé Sap River, on the other hand, only enjoys this diluting effect in May, during flow reversal, and even then, the Tonlé Sap experiences a surplus of suspended solids (SS) that are beneficial for soil fertility, yet, poor for water quality. 2. The water quality of both rivers is expected to be lower in the dry season than in the wet season. In addition to turbidity, the concentration of solids, FC, and nutrients are expected to increase as the volume of both rivers decrease. This season’s increase in temperature is also likely to contribute to lower DO saturation and higher biological oxygen demand (BOD). 7 8 Appendix 3 Appendix 4 9 Appendix 1.5 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 10 of 56 GEOGRAPHY HL V. Theoretical Background To best compare the water quality of the Tonlé Sap and Mekong River, it is important to understand the factors affecting water quality. 1. Dissolved Oxygen Most river organisms require high levels of dissolved oxygen to survive. Low DO concentration indicates a decay of organic material (such as sewage or vegetation) by microbial action or chemical processes. Q-value Dissolved Oxygen Saturation (%) Fig. 1.5.1: This weighing curve chart for (DO) Saturation demonstrates a positive correlation for dissolved oxygen concentration and water quality. 2. Fecal Coliform Fecal Coliform Test Results Fig. 1.5.2: This table shows a negative correlation between the number of FC colonies and water quality. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 11 of 56 GEOGRAPHY HL 3. pH pH Test Results Fig. 1.5.3: pH Test Results indicates that a neutral pH will yield the greatest water quality, since most organisms are unable to survive outside a neutral environment. 4. Biological Oxygen Demand 5-Day BOD Test Results Fig. 1.5.4: This chart demonstrates the negative correlation between water quality and BOD. The more oxygen is used up by organisms in the water after five days, the lower the WQI. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 12 of 56 GEOGRAPHY HL 5. Temperature Change Temperature (Water Quality Index Calculator) Based On Temperature Change from a Reference Site Warm climates sometime kill fish in ponds because the high temperatures reduce the oxygen concentration of the water. Temperature determines the maximum DO concentration in the water and influences the rate of chemical and biological reactions, thus determining which organisms can survive in the water. Fig. 1.5.5: This chart demonstrates that the smaller the change in temperature, the better the WQI. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 13 of 56 GEOGRAPHY HL 6. Nutrients Total Phosphates High levels of phosphates in water are associated with an excess of sewage, fertilizers, detergent or decaying plants. Nutrients from fertilizer leaked into rivers may cause excess algae or moss to grow on the surface of the water or turn the water green, thus preventing muchneeded sunlight from reaching the aquatic organisms. The absence of sunlight creates a decrease in the production of oxygen by plants through photosynthesis, which can then lead to decaying organisms and an even lesser water quality. Fig. 1.5.6.1: Phosphate Results demonstrate a negative correlation between water quality and total phosphates. Nitrates High levels of nitrates in water are associated with an excess of sewage, fertilizers, detergent or decaying plants, as explained in Fig. 1.5.6.3. Fig. 1.5.6.2: Nitrate results demonstrate a negative correlation between water quality and nitrates. Fig. 1.5.6.3. A slide from Aquanaut’s Analytes, Dr. Vermette’s Presentation to the MRC. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 14 of 56 GEOGRAPHY HL 8. Turbidity Turbidity Results . Fig. 1.5.8: Turbidity Results indicate a negative correlation between water quality and turbidity. 9. Total Solids Total Solids Test Result Fig. 1.5.9: Total Solids Test Results indicate a negative correlation between water quality and turbidity. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 15 of 56 GEOGRAPHY HL 10. Hardness Both hard and soft water are helpful depending on the need.10 11. Other Pollutants Other waste products which may be detrimental to organisms and infrastructure, include: microorganisms and inorganic chemicals, such as, metals, hydrocarbons, disinfectants and their byproducts.11 10 11 Appendix 5 Appendix 6 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 16 of 56 GEOGRAPHY HL Methodology I. General Method To best evaluate the water quality of the Tonlé Sap and Mekong River as many factors must be compared as possible. Due to limited resources, I will only collect and calculate data for the following: DO, FC, pH, BOD, temperature, nutrients, turbidity, and total solids. Later, values from both rivers will be compared and used to calculate their Water Quality Index (WQI)12 according to the NSF standard. Although this standard has not been specifically designed for tropical rivers,13 it allows a general comparison of water quality. So that the differences in season do not affect the accuracy of our comparisons, four samples will be used. Two samples will be taken from the dry season and two samples will be taken from the wet season. To accurately portray each season, samples will be taken in the middle of each season.14 II. Location of Sample Sites To fairly compare these two rivers, samples will be taken from Site 2 on the Tonlé Sap River and Site 4 on the Mekong River, since both sites lead up the confluence. Site 1 will be compared with Site 4 because of their varying distance from Phnom Penh center and may inaccurately represent the effects of urbanization on each river. Sites 3 and 5 will not allow a clear comparison between the rivers in question since they contain samples of both rivers. SITE 1 SITE 4 SITE 2 SITE 5 GPS Coordinates (m)15 2 Tonlé Sap 491400 1281957 4 Mekong 495820 1277387 Table 2.2.1: GPS Coordinates of river sites. Site River SITE 3 Fig. 2.2.1: Satellite photograph of the five possible testing sites students were limited to in this investigation 12 13 Appendix 7 Appendix 11 14 Appendix 6.5 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 17 of 56 GEOGRAPHY HL III. Data Collection Methods Tests for DO, FC, pH, BOD, temperature, nutrients, turbidity and total solids were done in the following ways because of the portability, availability and low cost of the equipment required for each measurement. 1. Temperature Fig. 2.3.1 2. pH Fig. 2.3.2: Annotated image demonstrating colorimetric testing method. 15 Value refers to UTM coordinate system, based on the WGS84 ellipsoid in zone 48P. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 18 of 56 GEOGRAPHY HL 3. Turbidity16 Fig. 2.3.3 4. Dissolved Oxygen Saturation17 Fig. 2.3.4.1 Fig. 2.3.4.2: Colorimetric method requires using Comparator Ampoules. 16 17 Appendix 8 Appendix: 9 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 19 of 56 GEOGRAPHY HL 5. Biological Oxygen Demand Fig. 2.3.5 6. Nitrates Fig. 2.3.6 7. Total Phosphates Fig. 2.3.7 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 20 of 56 GEOGRAPHY HL 8. Fecal Coliform18 Fig. 2.3.8 9. Total Solids Total solids are the sum of dissolved solids (DS) and SS. Dissolved Solids 18 This tests for Escherichia coli, a type of FC. Because 80 to 95% of FC found in feces are E-coli, the absence of E. Coli indicates few FC. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 Fig. 2.3.9.1 1222 Page 21 of 56 GEOGRAPHY HL Suspended Solids Fig. 2.3.9.2: Annotated photo detailed how MITYVAC filtration equipment was used. Fig. 2.3.9.3 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 22 of 56 GEOGRAPHY HL 10. Water Quality Index19 The NSF website provides a WQI calculator which employs the tables presented in IV. Theoretical Knowledge to indicate a water quality index (WQI) for each of the 9 factors and combine them to create one value ranging from 1-100 specifying the sample’s water quality. Fig. 2.3.11: Water Quality Index Calculator 19 Appendix 7 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 23 of 56 GEOGRAPHY HL IV. Evaluation of Data Collection Methods The methods used boasted several advantages: they were straightforward enough for secondary students to carry out; the fact that they were donated eliminated most costs involved; aside from small battery-operated instruments, no electricity was necessary and the equipments’ portability was high. However, several aspects of the data collection methods may have lead to inaccuracies, especially due to their interrelated nature.20 Many of the methods21 were colorimetric and therefore, influenced by operator characteristics, such as eyesight.22 The test for temperature and DS was electronic, so there was a smaller margin for human error.23 Finally, the WQI was devised in a temperate climate and intended for temperate rivers, not tropical rivers.24 Appendix 7.5 DO, pH, BOD, total phosphates, nitrates, turbidity and FC. 22 Appendix 8 and 9 23 The human factor may still have affected our results, though, since measuring temperature depended on the way water was retrieved for the test. Students were instructed to collect water 2-3 inches below the river surface but people may have lowered the container deeper or shallower into the water than each other, changing the effect of the sun on the water sample’s temperature. 24 Appendix 11: Evaluation of WQI 21 20 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 24 of 56 GEOGRAPHY HL Results I. Collected Data Tonlé Sap River Dry Wet Season Season 15.750 9.860 7.0 7.5 28.85 28.95 0.1 0.1 0.1 0.1 5.5 6.0 3.5 3.0 2 3 69.5 77.0 60 60 20 105 80.0 165.0 19 55 725 1050 68.5 69.0 Mekong River Dry Wet Season Season 33.465 4.935 7.0 7.0 28.75 28.50 0.1 0.1 0.1 0.1 6.5 6.0 4.5 3.0 2 3 82.0 75.0 125 65 8.5 190 133.5 255.0 10 66 350 1425 72.5 67.5 Test Secchi (in) pH Temperature (°C) Nitrate (ppm) Phosphate (ppm) Dissolved Oxygen (ppm) Dissolved Oxygen in 5 day (ppm) Biological Oxygen Demand (ppm) Dissolved Oxygen (%) Dissolved Solids (ppm) Suspended Solids (ppm) Total Solids (ppm) Turbidity (NTU) E. coli (# of colonies/100mL) Water Quality Index (Q-Value) Table 3.1.1: All data calculated from the Tonlé Sap River and Mekong River25 Test pH Temperature (°C) Nitrates (ppm) Total Phosphates (ppm) Biological Oxygen Demand (ppm) Dissolved Oxygen (%) Total Solids (ppm) Turbidity (NTU) FC (# of E. coli colonies/100mL) Water Quality Index (Q-Value) Table 3.1.2: Factors affecting water quality26 Site 2 7.25 28.9 0.1 0.1 2.50 50.975 122.50 37.0 887.5 68.75 Site 4 7.50 28.7 0.1 0.1 1.75 58.185 174.25 45.5 837.5 70.0 Tonlé Sap River Mekong River Water Quality Index Sample 1 Sample 2 Average Sample 1 Sample 2 Average Wet Season Samples 68.00 70.00 69.00 69.00 66.00 67.50 Dry Season Samples 73.00 64.00 68.50 77.00 68.00 72.50 Average 70.50 67.00 68.75 73.00 67.00 70.00 Table 3.1.3: Water Quality Index of the Tonlé Sap River and Mekong River27 25 26 Each season’s data averaged from two samples, taken each season from each river. Each site’s data averaged from four samples taken from each site (two from each season). 27 Appendix 12 Water Quality Index of the Tonlé Sap River and Mekong River 73 72 II. Presentation of Data 71 70.00 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 70 68.75 Water Quality 69 Index 68 67 66 65 Average Wet Season Dry Season Mekong River Water Sample Average Tonlé Sap River Wet Season Dry Season 1222 Page 25 of 56 GEOGRAPHY HL Fig. 3.2.1: Water Quality of Index of the Tonlé Sap River and Mekong River Tonlé Sap River Wet Season Tonlé Sap River Dry Season Tonlé Sap River Average Mekong River Wet Season Mekong River Dry Season Mekong River Average Water Quality Index of the Tonlé Sap River and Mekong River during the Dry Season 80 72.5 68.5 70 60 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 50 Water Quality 40 Index 30 20 Tonlé Sap River January Tonlé Sap River February Tonlé Sap River Average Mekong River January Mekong River February Mekong River Average 10 0 February Average January February Mekong River Water Sample Fig. 3.2.2.: Water Quality Index of the Tonlé Sap River and Mekong River January Tonlé Sap River Average 1222 Page 26 of 56 GEOGRAPHY HL Water Quality Index of the Tonlé Sap River and Mekong River during the Wet Season 70.0 69.0 69.0 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 68.0 67.5 Water Quality 67.0 Index 66.0 65.0 64.0 August Tonlé Sap River Water Sample Fig. 3.2.3.: Water Quality Index of the Tonlé Sap River and Mekong River September Average August September Mekong River Average Tonlé Sap River August Tonlé Sap River September Tonlé Sap River Average Mekong River August Mekong River September Mekong River Average 1222 Page 27 of 56 GEOGRAPHY HL International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 28 of 56 GEOGRAPHY HL III. Analysis and Evaluation of Data The first hypothesis is correct: the Mekong River does have a higher water quality than the Tonlé Sap River when controlling for wet and dry season (Fig. 3.2.1). The rivers are on a border line between medium and good high water quality, with the Mekong River more often corresponding to a good WQI (Table 3.1.3 and 3.3.1). Table 3.3.1 Possible explanations for this may include the sewage dispatched by the large boating community on the Tonlé Sap Lake (Fig. 3.3.1), where the largest incident of inland fishing in the world takes place.28 This is likely to affect the WQI of the Tonlé Sap River, especially in the dry season, where the volume is lowest, increasing the concentration of waste. Table 3.1.1 shows an SS value for the Tonlé Sap River which more than doubles the Mekong River’s SS value. Fig. 3.3.1: Overhead image of the fishing community on the Tonlé Sap Lake, a source of the Tonlé Sap River. 28 WWF Report: World’s Top Ten Rivers at Risk. WWF. http://assets.panda.org/downloads/worldstop10riversatriskfinalmarch13_1.pdf Date accessed 11/02/06 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 29 of 56 GEOGRAPHY HL Because of Tonlé Sap River’s proximity to Cambodia’s primate city, it would also be affected by the city’s commercial enterprises (Fig 3.3.2). Fig. 3.3.2: Images of a boat transporting sand (left) and gasoline (right). However, a closer look at Tables 3.1.1 and 3.1.3 and Figures 3.2.3 and 3.2.4 shows that the Tonlé Sap River’s lesser WQI only occurs during the dry season. In the wet season, the Tonlé Sap River’s water quality is greater than the Mekong River’s. This was unexpected due to the undeveloped nature of the area around the Mekong River in Phnom Penh and also because of the Mekong River’s expected capacity to dilute waste products (due to a large volume which would only increase in the wet season). However, the Mekong River’s high turbidity and sediment values (Fig. 3.3.3) nearly double the Tonlé Sap River’s amounts in the wet season (Table 3.1.1). Fig. 3.3.3: Sediment containing filter paper from a wet season SS test, placed on an image of Fig. 1.1.2. A possible explanation includes increased logging. In Cambodia, the annual deforestation rate has risen by 74.7% between 2000 and 2005.29 This is more likely to be carried out near the Mekong River, in the outer city, where more vegetation is available.30 Also, the increased rain in the Mekong River during the flood season, thought to be able to dilute waste products, has instead, increased the 29 30 Cambodia. http://rainforests.mongabay.com/deforestation/2000/Cambodia.htm Date Accessed: 11/07/07 Vegetation inhibits soil erosion. Tree roots to hold the soil together preventing rainwater from sweeping silt into rivers. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 30 of 56 GEOGRAPHY HL river’s velocity, eroding the loose, undeveloped banks of the Mekong River significantly more than the Tonlé Sap River’s banks, which are much shorter. Fig. 3.3.4: A fishing boat by the Tonlé Sap’s cemented banks in Phnom Penh. Increased amounts of DS in the Mekong River from the dry season to the wet season can be attributed to the increased surface flow in the presence of rain which washes more minerals into the river. The Mekong River’s higher DS values than the Tonlé Sap River’s can be explained by residue left behind by traffic, since higher water levels greatly ease transportation between countries in the Mekong River’s lower basin (Fig. 3.3.5). Fig. 3.3.5: A fishing boat traveling on the Mekong River during the flood season. The second hypothesis is only partly true. Mostly due to a sharp decrease in DO, the Tonlé Sap River’s WQI is higher in the wet season than in the dry season (despite sharp increases in turbidity and E. coli). Conversely, the WQI of the Mekong River decreases, mostly because of increased turbidity. Velocity, caused by an increase in river volume, prevents solids from to settling on the riverbed, augmenting turbidity. Also, the wet season caused an unprecedented rise in FC which was overlooked when determining the hypothesis. Logically, higher water levels increase accessibility of the river, allowing more organisms to defecate in it. Added to this, increased humidity provides more resources and breeding grounds to FC. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 31 of 56 GEOGRAPHY HL However, when analyzing the data in its entirety, the overall differences between each season and each river’s WQI are too small to be considered significant.31 Not all contaminants have been measured in this investigation32 and the interrelated nature of these rivers makes it difficult to accurately compare each river (Fig. 3.3.6).33 Fig. 3.3.6: Origin of Tonlé Sap Lake’s Water Though possible for these two rivers to maintain similar WQI values throughout the year, it is important to revisit the limitations of the methods of study.34 Firstly, the WQI was not designed to evaluate tropical rivers and therefore, could be inaccurate.35 Secondly, this investigation’s calculated WQI is based only on eight factors, not nine.36 Thirdly, some inaccuracies may be attributed to human error and natural, annual variations of the river. Finally, Table 3.3.2 indicates the uncertainty values of the equipment and methods employed in this investigation. Test Secchi (cm) pH Hardness (ppm) Temperature (°C) Nitrate (ppm) Phosphate (ppm) Dissolved Oxygen (ppm) Biological Oxygen Demand (ppm) Dissolved Oxygen (%) Dissolved Solids (ppm) Suspended Solids (ppm) Total Solids (ppm) Turbidity (NTU) E. coli (# of colonies/100mL) Water Quality Index (Q-value) Uncertainty (± units) 1 1 18 1 0.1 0.1 1 1 1 1 4 5 10 1 1 Table 3.3.2: Uncertainty values of factors measured. The sole average WQI change exceeding two units is the change from the Mekong River in the wet season to the dry season. See Appendix 12 & 13. 32 Appendix 6 33 The water quality of the Tonlé Sap River water contains great amounts of Mekong River water due to flow reversal. 34 See Methodology: IV. Evaluation of Data Collection Methods. 35 Appendix 11 36 Appendix 14 31 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 32 of 56 GEOGRAPHY HL With these inaccuracies in mind, this investigation does not prove nor disprove its hypotheses. The data shows generally constant levels of pH, hardness, temperature and nutrients and a good-toexcellent water quality. The rivers in question do not contain hazardous levels or fertilizers, decomposing organic matter or minerals, demonstrating that urbanization is actually a minor influence on the Tonlé Sap and Mekong River. Any fluctuations between each river’s WQI are attributed to seasonal variations in DO, total solids and FC. IV. Conclusion The Tonlé Sap and Mekong River were studied in order to evaluate their water quality while controlling for the changes in wet and dry season, as well as to determine the effect of the wet and dry season on their water quality. This was done by testing two hypotheses: 1) the Mekong River would yield a higher water quality than the Tonlé Sap River throughout the year and, 2) the wet season would yield a higher water quality than the dry season for both rivers. Data collected demonstrated that both hypotheses were only partly true. Because of the detrimental effect the wet season has on the Mekong River (affecting DO, SS and FC), the Mekong River actually only yields higher water quality than the Tonlé Sap during the dry season. Future investigations should focus specifically on DO, SS, and FC, as this investigation indicates these as the deciding factors in influencing water quality in Cambodia. It will also be important to continue studying WQI in Cambodia over time to appreciate emerging trends and set up a WQI standard for tropical rivers. The uniqueness of the reversal phenomenon in this area also warrants more study since there are no other rivers to compare these rivers to.37 The Mekong River Commission names agriculture, population pressure, economic development and fishery as the main stressors on WQI in Cambodia. In addition to measuring the effects of these things, it would be interesting to modify the hypotheses to compare the effects of deforestation, dams or sewerage systems on the WQI of these and other Cambodian rivers and their seasonal variations. 37 Smaller examples of river flow reversal exist but data available to the public is limited. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 33 of 56 GEOGRAPHY HL Bibliography About Floods in the Mekong Basin. The Mekong River Commission. http://www.mrcmekong.org/flood_report/2006/about-foods.htm Date accessed November 3, 2007. Aquanaut’s Analytes. Vermette, S. J. Power Point Presentation to the MRC. Cambodia. http://rainforests.mongabay.com/deforestation/2000/Cambodia.htm Date Accessed: 11/07/07 Coliscan Tests. http://www.nscollegeprep.cps.k12.il.us/depts/science/avites/AP%20Watercoliform_tests.htm Date accessed: November 2, 2007 Did You Know? The Mekong River Commission. http://www.mrcmekong.org/MfS/html/did_you_know.html 11/02/07 Foote K. E., and Molch, K. E. Effects of Urbanization on Environment: An Overview http://www.colorado.edu/geography/virtdept/stylesheets/samples/machine_space/html/body .html November 2, 2007 Geography of Cambodia. http://www.tourismindochina.com/geography-cambodia.htm Date accessed: 11/02/07 Hard vs. Soft Water Explained. http://www.freedrinkingwater.com/water-education/qualitywater-hard.htm Date Accessed: November 2, 2007 How exactly does dissolved oxygen affect water quality? http://www.freedrinkingwater.com/water_quality/quality1/1-how-dissolved-oxygen-affectswater-quality.htm Date Accessed: November 2, 2007 http://www.ifredi.org/Documents/BS/Built%20Structures%20synthesis.pdf Date Accessed: 11/02/07 Ikeazota, S. I. & Jeje L.K. Effects of Urbanization on Channel Morphology: The Case of Ekulu River in Enugu, South Eastern Nigeria http://www.blackwell-synergy.com/doi/abs/10.1111/14679493.00117?cookieSet=1&journalCode=sjtg Date accessed: November 3, 2007 Mekong River Watershed. http://en.wikipedia.org/wiki/Image:Mekong_River_watershed.png Date accessed: November 2, 2007 MRC, World Fish Center. Influence of Built Structures on Tonle Sap Fisheries. MRC (2007) Diagnostic study of water quality in the Lower Mekong Basin. MRC Technical Paper No. 15, Mekong River Commission, Vientiane. 57pp. Office of Council of Ministers. Inland Waterways. http://www.ocm.gov.kh/c_inf3.htm Date accessed: 11/02/07 Overview of Contaminants & Their Potential Health Effects. http://www.freedrinkingwater.com/water-education/water-contaminants-health-effects.htm Date accessed: November 2, 2007 Rosenboom, Jan-Willem (2004) Not Just Red or Green: An analysis of arsenic data from 15 upazillas in Bangladesh. Arsenic Policy Support Unit, Dhaka. Seasons of Cambodia. http://www.travelfish.org/cambodia-weather.php Date accessed: November 2, 2007 Structural Analysis of Deforestation in Cambodia. http://www.iges.or.jp/en/fc/phase1/ir99/4-13ruth.pdf Date accessed: 11/02/07 Structural Analysis of Deforestation in Cambodia. http://www.iges.or.jp/en/fc/phase1/ir99/4-13ruth.pdf Date accessed: 11/02/07 The Source of Life. Powerpoint presentation by Dr. S.J. Vermette from New York State University at Buffalo’s Aquanaut Program. Tonlé Sap Database. http://www.sumernet.org/tonlesap/eng/news/news_detail.asp?id=59 11/02/07, Tracing the Mekong River. http://www.hawaii.edu/hga/gaw01/workshop/TracingMekongRiv.html 11/02/07 - - - - - International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 34 of 56 GEOGRAPHY HL - - - Tracing the Mekong River. http://www.hawaii.edu/hga/gaw01/workshop/TracingMekongRiv.html 11/02/07 Turbidity. Australian Government. http://www.waterwatch.org.au/publications/module4/turbidity.html Date accessed : November 3, 2007 Vietnam plans Mekong mega dam in Laos http://www.straitstimes.com/Latest%2BNews/Asia/STIStory_190092.html Dec 25, 2007 Water Quality Index: Iowa. The Iowa Department of Natural Resources. http://wqm.igsb.uiowa.edu/wqi/wqi.asp 11/02/07 Water, the Source of Life. PowerPoint presentation by Dr. S.J. Vermette from New York State University at Buffalo’s Aquanaut Program. WELCOME TO PROJECT CHILDREN. http://www.projectchildrenni.com/states.htm 11/02/07 Why Temperature is Important. http://www.water-research.net/Watershed/temperature.htm Date accessed: November 2, 2007 WWF Report: World’s Top Ten Rivers at Risk. WWF. http://assets.panda.org/downloads/worldstop10riversatriskfinalmarch13_1.pdf Date accessed 11/02/06 www.ocm.gov.kh Date Accessed: November 11, 2007 Figures and Diagrams Fig. 1.1.1: Map/Still: Cambodia’ Encyclopædia Britannica. http://cache.eb.com/eb/image?id=4052&rendTypeId=4 Date accessed: November 2007. Fig. 1.1.2: Satellite image taken from Google Earth, April 4, 2005. Fig. 1.1.3 has been taken from: http://earthobservatory.nasa.gov/Newsroom/NewImages/images.php3?img_id=15294 Date accessed: 11/02/07 Fig. 1.1.4: http://www.mrcmekong.org/img/flood_report/2006/map1.gif 11/02/07 Fig.1.4.1: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig.1.5.1: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.2: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.3: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.4: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.5: taken from Why Temperature Is Important http://www.nsf.org/consumer/just_for_kids/wqi.asp Date Accessed: November 2, 2007 Fig. 1.5.6.1: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.6.2: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.6.3: Aquanaut’s Analytes. Vermette, S. J. Power Point Presentation to the MRC. Fig. 1.5.8: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Fig. 1.5.9: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 - International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 35 of 56 GEOGRAPHY HL - Fig.2.2.1: Source unknown. Fig. 2.3.1-2.3.9.2: Images taken by teacher and friends during field work, annotations by Pan, N. Fig. 2.3.9.3: Water, the Source of Life. PowerPoint presentation by Dr. S.J. Vermette from New York State University at Buffalo’s Aquanaut Program. Fig. 2.3.11: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Table 3.1.1-3.1.3: Results of Experiment carried out by IB Geography class, ISPP, ‘06-‘07 Fig. 3.2.1-3.1.3: Graphs by Pan, N. Table 3.3.1: taken from Calculating NSF Water Quality Index. http://www.waterresearch.net/watrqualindex/index.htm Date Accessed: November 2, 2007 Table 3.3.2: Source: Pan, N. Fig. 3.3.1: Source unknown. Fig. 3.3.2: Water, the Source of Life. PowerPoint presentation by Dr. S.J. Vermette from New York State University at Buffalo’s Aquanaut Program. Fig. 3.3.3: Photo credit: Pan, N. Fig. 3.3.4: Photo credit: Pan, N. Fig. 3.3.5: Photo credit: Pan, N. Fig. 3.3.6: ‘Origin of Tonlé Sap Lake’s Water’ taken from Influence of Built Structures on Tonle Sap Fisheries. http://www.ifredi.org/Documents/BS/Built%20Structures%20synthesis.pdf Date accessed: 01/10/2007 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 36 of 56 GEOGRAPHY HL Appendices Appendix 1: Tonlé Sap River’s Bi-Directional Unimodal Flow From mid-October the Tonlé Sap flows seaward, feeding the Mekong River at its confluence in Phnom Penh. However, as the wet season (also referred to as the monsoon season) continues and more rainwater and melted ice (from the Himalayas) flows into the Mekong River, the Mekong can no longer accept any water from the Tonlé Sap Lake and actually flows upslope into the lake, forcing the Tonlé Sap to reverse its flow around late May. Source: MRC Overview of the Hydrology of the Mekong Basin, November 2005:53 Tan Chau & Chau Doc = rivers on the Cambodia-Vietnam border also with a unimodal shape. Source: Diagnostic study of water quality in the Lower Mekong Basin., November 2007:12 Mean monthly discharge at selected locations showing the main tributaries in each reach. Arrows indicate from upstream to downstream. The period of record is 1960-2000 (MRC, 2004) International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 37 of 56 GEOGRAPHY HL This example of bi-directional flow is unique in the world; a drawback in this investigation for the results gathered in this study cannot be compared to another instance in the world. There are other smaller scale examples, but limited data is available on those streams. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 38 of 56 GEOGRAPHY HL Appendix 1.5: Tonlé Sap River’s River Volume River Volume Due to the unimodal flow of tributaries in the Lower Mekong River Basin and variations in season, the volume of the respective rivers is difficult to quantify. Also, there is limited information about this unique occurrence and the Tonlé Sap River and the Mekong River are greatly interrelated. This interrelatedness means that during the dry season, the Tonlé Sap River feeds the Mekong River and in the wet season the Mekong River feeds the Tonlé Sap River, making it difficult to determine the respective volume of each river. Appendix 2: Seasons of Cambodia Dry season – runs from November to April on the back of the northeast monsoon. Months between November to January are cooler and humid while between February to April months are hot and dusty. November is the coolest month, April the hottest. Wet season - runs from May to October courtesy of the southwest monsoon. Wet season brings some 75% of Cambodia's annual rainfall. Months between July and September are the wettest months. Source: Seasons of Cambodia. http://www.travelfish.org/cambodia-weather.php Date accessed: November 2, 2007 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 39 of 56 GEOGRAPHY HL Appendix 3: The Effects of Urbanization Dangers of Urbanization Urban areas have the potential to pollute water in many ways. Runoff from streets carries oil, rubber, heavy metals, and other contaminants from automobiles. Untreated or poorly treated sewage can be low in dissolved oxygen and high in pollutants such as fecal coliform bacteria, nitrates, phosphorus, chemicals, and other bacteria. Treated sewage can still be high in nitrates. Groundwater and surface water can be contaminated from many sources such as garbage dumps, toxic waste and chemical storage and use areas, leaking fuel storage tanks, and intentional dumping of hazardous substances. Air pollution can lead to acid rain, nitrate deposition, and ammonium deposition, which can alter the water chemistry of lakes. Source: Dangers of Urbanization. http://www.livinglakes.org/issues/pollution.html Date accessed: November 2, 2007 In urban areas, there is less interception from plants, which directs rainwater directly to the ground level where the soil is either compacter or covered in tarmac or concrete, creating an impermeable surface, that allows large volumes of rapid surface flow. This running water dissolves minerals found on the surface of cities and transports them to rivers and sewerage systems. Appendix 4: Heat, as an Effect of Urbanization Effects of Urbanization on Environment: An Overview Cities are made of concrete, asphalt, brick, stone, and steel. These materials absorb and reflect energy differently than vegetation and soil. They absorb more radiant energy and radiate this energy back into the atmosphere at different times through the day. The result is that cities are warmer than the surrounding countryside, sometimes considerably. Furthermore, cities remain warm well into the night when the countryside has already cooled. Source: Foote K. E., and Molch, K. E. Effects of Urbanization on Environment: An Overview http://www.colorado.edu/geography/virtdept/stylesheets/samples/machine_space/html/body.html November 2, 2007 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 40 of 56 GEOGRAPHY HL Appendix 5: Hard & Soft Water Explained Hard water contains dissolved minerals which can corrode pipes and infrastructure. Rain water is an example of softer water, containing less of these minerals and more sodium ion. Both hard and soft water can be useful. HARD vs. SOFT WATER EXPLAINED -Hard water is water that contains an appreciative quantity of dissolved minerals (like calcium and magnesium) -Soft water is treated water in which the only ion is sodium. As rainwater falls, it is naturally soft. However, as water makes its way through the ground and into our waterways, it picks up minerals like chalk, lime and mostly calcium and magnesium. Since hard water contains essential minerals, it is sometimes the preferred drinking water, not only because of the health benefits, but also the flavor. On the other hand, soft water tastes salty and is sometimes not suitable for drinking. So why, then, do we soften our water? When it boils down, the major difference between hard and soft water can best be seen while doing household chores. Hard water is to blame for dingy looking clothes, dishes with spots and residue and bathtubs with lots of film and soap scum. Even hair washed in hard water may feel sticky and look dull. Hard water can take a toll on household appliances as well, using up more energy. The elements of hard water are to blame for all of these negative factors, as soap is less effective due to its reaction to the magnesium and calcium. The lather is not as rich and bubbly. Chore-doers will love using soft water, as tasks can actually be performed more efficiently with it. Soap will lather better and items will be left cleaner. Glasses will sparkle and hair will look healthy. The shower curtain will be scum-free. Clothes and skin are left softer. In addition to time, this can also save money, as less soap and detergents will be used. Since appliances have to work less hard, soft water can also prolong the life of washing machines, dishwaters and water heaters. Energy bills are noticeably lower when in households with water softeners. In a time of rising energy costs, this is something to think about. Soft water is not, however, suggested for those with heart or circulatory problems, or others who may be on a low sodium diet. In the softening process, as minerals are removed, sodium content increases. Research shows that cardiovascular disease has the lowest risk in areas where water has the most mineral content. Source: Hard vs. Soft Water Explained. http://www.freedrinkingwater.com/water-education/quality-waterhard.htm Date Accessed: November 2, 2007 Image taken from Aquanaut’s Analytes, Dr. Vermette’s Presentation to the MRC. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 41 of 56 GEOGRAPHY HL Appendix 6: Complete List of Possible River Water Contaminants Overview of Contaminants & Their Potential Health Effects. Microorganisms Contaminant Potential Health Effects from Ingestion of Water Gastrointestinal illness (e.g., Cryptosporidium diarrhea, vomiting, cramps) Gastrointestinal illness (e.g., Giardia lamblia diarrhea, vomiting, cramps) Heterotrophic plate HPC has no health effects; it is an analytic method used to measure count the variety of bacteria that are common in water. The lower the concentration of bacteria in drinking water, the better maintained the water system is. Legionnaire's Disease, a type of Legionella pneumonia Not a health threat in itself; it is Total Coliforms used to indicate whether other (including fecal coliform and E. Coli) potentially harmful bacteria may be present5 Sources of Contaminant in Drinking Water Human and fecal animal waste Human and animal fecal waste HPC measures a range of bacteria that are naturally present in the environment Turbidity Viruses (enteric) Turbidity is a measure of the cloudiness of water. It is used to indicate water quality and filtration effectiveness (e.g., whether disease-causing organisms are present). Higher turbidity levels are often associated with higher levels of disease-causing microorganisms such as viruses, parasites and some bacteria. These organisms can cause symptoms such as nausea, cramps, diarrhea, and associated headaches. Gastrointestinal illness (e.g., Human and animal fecal waste diarrhea, vomiting, cramps) Found naturally in water; multiplies in heating systems Coliforms are naturally present in the environment; as well as feces; fecal coliforms and E. coli only come from human and animal fecal waste. Soil runoff Disinfection Byproducts Contaminant Bromate Chlorite Haloacetic acids (HAA5) Total Trihalomethanes (TTHMs) Potential Health Effects from Ingestion of Water Increased risk of cancer Anemia; infants & young children: nervous system effects Increased risk of cancer Liver, kidney or central nervous system problems; increased risk of cancer Sources of Contaminant in Drinking Water Byproduct of drinking water disinfection Byproduct of drinking water disinfection Byproduct of drinking water disinfection Byproduct of drinking water disinfection International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 42 of 56 GEOGRAPHY HL Disinfectants Contaminant Chloramines (as Cl2) Chlorine (as Cl2) Chlorine dioxide (as ClO2) Potential Health Effects from Ingestion of Water Eye/nose irritation; stomach discomfort, anemia Eye/nose irritation; stomach discomfort Sources of Contaminant in Drinking Water Water additive used to control microbes Water additive used to control microbes Anemia; infants & young children: Water additive used to control nervous system effects microbes Inorganic Chemicals Contaminant Antimony Potential Health Effects from Ingestion of Water Increase in blood cholesterol; decrease in blood sugar Skin damage or problems with circulatory systems, and may have increased risk of getting cancer Increased risk of developing benign intestinal polyps Increase in blood pressure Sources of Contaminant in Drinking Water Discharge from petroleum refineries; fire retardants; ceramics; electronics; solder Erosion of natural deposits; runoff from orchards, runoff from glass & electronicsproduction wastes Decay of asbestos cement in water mains; erosion of natural deposits Discharge of drilling wastes; discharge from metal refineries; erosion of natural deposits Discharge from metal refineries and coal-burning factories; discharge from electrical, aerospace, and defense industries Corrosion of galvanized pipes; erosion of natural deposits; discharge from metal refineries; runoff from waste batteries and paints Discharge from steel and pulp mills; erosion of natural deposits Arsenic Asbestos (fiber >10 micrometers) Barium Beryllium Intestinal lesions Cadmium Kidney damage Chromium (total) Allergic dermatitis Copper Short term exposure: Corrosion of household Gastrointestinal distress plumbing systems; erosion of Long term exposure: Liver or natural deposits kidney damage People with Wilson's Disease should consult their personal doctor if the amount of copper in their water exceeds the action level Nerve damage or thyroid problems Bone disease (pain and tenderness of the bones); Discharge from steel/metal factories; discharge from plastic and fertilizer factories Water additive which promotes strong teeth; erosion of natural Cyanide (as free cyanide) Fluoride International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 Children may get mottled teeth Lead 1222 Page 43 of 56 GEOGRAPHY HL deposits; discharge from fertilizer and aluminum factories Infants and children: Delays in Corrosion of household physical or mental development; plumbing systems; erosion of children could show slight deficits natural deposits in attention span and learning abilities Adults: Kidney problems; high blood pressure Kidney damage Erosion of natural deposits; discharge from refineries and factories; runoff from landfills and croplands Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits Mercury (inorganic) Nitrate (measured as Nitrogen) Infants below the age of six months who drink water containing nitrate in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Infants below the age of six months who drink water containing nitrite in excess of the MCL could become seriously ill and, if untreated, may die. Symptoms include shortness of breath and blue-baby syndrome. Nitrite (measured as Nitrogen) Runoff from fertilizer use; leaching from septic tanks, sewage; erosion of natural deposits Selenium Hair or fingernail loss; numbness Discharge from petroleum in fingers or toes; circulatory refineries; erosion of natural problems deposits; discharge from mines Hair loss; changes in blood; kidney, intestine, or liver problems Leaching from ore-processing sites; discharge from electronics, glass, and drug factories Thallium Radionuclides Contaminant Alpha particles MCL or Potential Health Effects from TT1 Ingestion of Water (mg/L)2 15 Increased risk of cancer picocuries per Liter (pCi/L) 4 Increased risk of cancer millirems per year Sources of Contaminant in Drinking Water Erosion of natural deposits of certain minerals that are radioactive and may emit a form of radiation known as alpha radiation Decay of natural and manmade deposits of certain minerals that are radioactive and may emit forms of radiation known as photons and beta radiation Erosion of natural deposits Beta particles and photon emitters Radium 226 and Radium 228 (combined) 5 pCi/L Increased risk of cancer International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 Uranium 30 ug/L Increased risk of cancer, kidney as of toxicity 12/08/03 1222 Page 44 of 56 GEOGRAPHY HL Erosion of natural deposits Source: Overview of Contaminants & Their Potential Health Effects. http://www.freedrinkingwater.com/watereducation/water-contaminants-health-effects.htm Date accessed: November 2, 2007 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 45 of 56 GEOGRAPHY HL Appendix 6.5: Length of Cambodian Seasons Ideally, the tests in this investigation would be carried out several times a month, every month for several years, but instead, the above was carried out only one time every month, and only while school was in session. This led to an absence of samples for the wet season (June and July) and no samples in the beginning of the dry season (November), which affected which samples I chose to compare in my investigation.38 The uneven number of samples from the wet and dry season would have made a comparison between, for example, an average of the Tonlé Sap’s wet season measurements and an average of the Tonlé Sap’s dry season measurements inaccurate, as explained by Fig. 3.4.1. Fig. 3.4.1: Hydrograph depicting the dry season and the wet season (labeled here as the flood season).39 Graph based on mean annual hydrograph recorded at Kratie, Cambodia, a province northeast of Phnom, also on the Mekong River. This demonstrates that the dry season is longer than the wet season, so two months of the wet season missing from the records would indeed misrepresent the two rivers being studied. Even without missing samples, it is important that the same number of samples from each season be compared for each river and vice versa. Also, the more samples tested the more accurate our results will be, since an average of three measurements in a single season would best represent that season. However, the maximum number of results from a single season which can be tested is 3 – August, September and October – in July; school was not in session so we could not take measurements. Therefore, it would make sense for me to choose three months from the dry season as well. However, because October is part of Transition Season 2, I did not want the period of flow reversal to influence the river’s water quality readings. Though not expressed on this graph, many other sources including the Office of Council of Ministers in Cambodia40 state that October is when the Tonlé Sap begins changing directions. Therefore, I have decided to choose two samples near the middle of each season for each river,41 which I have averaged and compared. 38 39 Please see Introduction: II. Aims of the Investigation About Floods in the Mekong Basin. The Mekong River Commission. http://www.mrcmekong.org/flood_report/2006/aboutfoods.htm Date accessed November 3, 2007. 40 www.ocm.gov.kh Date Accessed: November 11, 2007 41 Please see Methodology: I. General Method International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 46 of 56 GEOGRAPHY HL Appendix 7: Information about WQI Water Quality Index: Iowa In 1970, the National Sanitation Foundation developed the Water Quality Index (WQI), a standardized method for comparing the water quality of various water bodies. In Iowa, the WQI is calculated by using eight common water quality parameters (dissolved oxygen, fecal coliform bacteria, pH, 5-day BOD, total phosphorus, nitrate-nitrogen, turbidity, and total dissolved solids). Values range from 0 – 100 and streams are classified as poor (0-25), fair (25-50), medium (50-70), good (70-90), or excellent (90-100). Source: Water Quality Index: Iowa. The Iowa Department of Natural Resources. http://wqm.igsb.uiowa.edu/wqi/wqi.asp Date accessed: November 2, 2007 The following website, maintained by Wilkes University’s Center for Environmental Quality, Environmental Engineering and Earth Sciences, was used to calculate the NSF Water Quality Indexes in this investigation. Screen shot of: http://www.water-research.net/watrqualindex/index.htm This WQI standard has been used to indicate the general water quality of a river and not the water quality recommended for a specific activity e.g. drinking, swimming, cooking, etc. For example, this standard has not taken into account the concentration of sodium chloride as well – which is necessary for some forms of aquaculture. The following table shows the values the Mekong River Commission uses to determine water quality based on several factors. When viewed in contrast with V. Theoretical Background, this table demonstrates the minor differences present in each organization’s parameters of measuring water quality. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 47 of 56 GEOGRAPHY HL Diagnostic study of water quality in the Lower Mekong Basin. 2007: 17 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 48 of 56 GEOGRAPHY HL Appendix 7.5: Improving the Precision and Accuracy of Data Collection Precision and accuracy In all experimental measurements, there is a degree of uncertainty or error. When reporting data, the degree of uncertainty can be measured by considering the precision and accuracy of the analysis. The precision simply means the reproducibility of the analysis: If the same sample is analyzed multiple times, how much will the results vary? Accuracy, on the other hand, refers to how close the measurement is to the true value. Analytical precision can be assessed by making repeat measurements and calculating the ratio of the standard deviation to the average. This is called the coefficient of variation, and as a rule of thumb should be less than 10% for laboratory measurements. Precision will depend primarily upon the instrument and method, but also on the operator and quality control procedures. The picture below illustrates these concepts: Not precise, not accurate Accurate, not precise Precise, not accurate Accurate and precise Source: Rosenboom, Jan-Willem (2004) Not Just Red or Green: An analysis of arsenic data from 15 upazillas in Bangladesh. Arsenic Policy Support Unit, Dhaka. Precision of the measurements carried out for the river water analysis cannot be assessed, since only one single measurement was performed on each monthly because of lack of resources. Therefore, to improve accuracy and precision, we must eliminate issues of quality control. This could be done through using standard procedures, training operators, taking multiple samples and comparing data collected with existing scientific literature. With the limited method that we have, we were all taught a standard method by a qualified chemist, who stressed to us the importance of following the standard procedures outlined in III. Data Collection Methods. In regards to multiple samples, as mentioned in Appendix 6.5, and the conclusion, although we would ideally want to compare as many samples of each season and for as long as possible (a decade or more), this was not possible during the two years of our project. Also mentioned in the body of the essay, it is extremely difficult to find data to compare the results of this investigation to because of the unique hydrological system found in Cambodia. Another way to improve quality and precision is by following the Standard Methods for the Examination of Water and Wastewater’s official website standardmethods.org, put together by the American Public Health Association, the American Water Works Association and the Water Environment Federation, which provides extensive guidelines on how to best evaluate water quality. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 49 of 56 GEOGRAPHY HL It indicates that when using colorimetric methods, the use of an instrument called a photometer would eliminate the dependency the results have on the operator, to reduce bias and increase accuracy and precision. Since so many of our experiments use colorimetric methods, the use of a photometer would have greatly increased the precision and accuracy of our results. The increased accuracy would be especially useful for measuring nutrients. In this investigation, it has always been difficult to distinguish between 0.1 ppm or <0.1 ppm. Electronic instruments would make the process more convenient for pH, as well. Since this measurement is affected by temperature, it would be doubly useful to have an instrument that could take this into account too. However, as shown by the figure below, these types of instruments are expensive, and therefore explain why we have used the equipment donated to us by the New York State University through the Buffalo Aquanaut Program. Waterproof pH and Temperature Thermometer A superb digital dip-and-read meter, automatic 2 point self calibrating feature, Full microprocessor circuit with automatic compensation resolution 0.1 and temperature meter can be set to f or c scale Batteries, Instructions, & 2 buffer calibration solutions are included free. Replaceable pH probe. Temperature can be set to either F or C scale. Batteries, 2 buffer solutions and instructions are included. Code Product Price DPHM Waterproof pH and Temperature Thermometer £79.00 Source: http://www.absolute-koi.com/water_testing/hanna.html Date accessed: 11/02/07 Order International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 50 of 56 GEOGRAPHY HL Appendix 8: Turbidity Once secchi depth is measured (see right), turbidity can be calculated using a scale (see above). By connecting the value of the site’s secchi depth (on the top scale) with the turbidity in nephelometric turbidity units (NTUs) (on the bottom scale), we can determine what the turbidity measurement is. This diagram is a visual representation of the positive correlation between secchi depth and turbidity. It also demonstrates that the values calculated for turbidity saturation may not be very accurate since the subjective personal judgment must be used to estimate which value corresponds to which, since there are not enough marks between each unit. This is especially difficult because of its logarithmic increments. Varied lighting at each site may have further contributed to the inaccuracy of these tests. Turbidity indicates water quality by measuring the cloudiness of water. Higher turbidity may indicate low filtration effectiveness because of the high prevalence of disease-causing microorganisms such as viruses, parasites and bacteria or may be due to suspended solids and algae. Pathogens can cause nausea, cramps, diarrhea and headaches, while water cloudiness can block sunlight, leading to less oxygen produced by plants through photosynthesis, decaying plants and a lesser water quality. Suspended solids also absorb heat, making temperature rise faster in turbid water, thus lowering the DO concentration. They can also harm aquatic organisms in the water, such as fish.43 42 42 Image taken from: Turbidity. Australian Government. http://www.waterwatch.org.au/publications/module4/turbidity.html Date accessed : November 3, 2007 43 Turbidity. Australian Government. http://www.waterwatch.org.au/publications/module4/turbidity.html Date accessed : November 3, 2007 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 51 of 56 GEOGRAPHY HL Appendix: 9: % DO Saturation By using a straight line to connect the value of the site’s temperature (on the top scale) with the DO in parts per million (on the bottom scale), we can determine what the percentage of DO saturation is by recording where the straight line intersects with the scale for % saturation (on the middle diagonal scale). This diagram is a visual representation of temperatures effect on water’s maximum ability to absorb oxygen (DO Saturation). It also demonstrates that the values calculated for DO saturation may not be very accurate since the subjective personal judgment must be used to estimate where lines intersect, if there are not enough marks between each unit. Also, if water temperature exceeds 30 centigrade, an estimated extension of the top scale must be created, which is especially difficult because of its logarithmic increments Appendix 10: Hardness Concentration 1 drop = 18 ppm 2 drop = 36 ppm 3 drop = 54 ppm 4 drop = 72 ppm 5 drop = 90 ppm 6 drop = 107 ppm 7 drop = 125 ppm 8 drop = 143 ppm 9 drop = 161 ppm 10 drop = 179 ppm 11 drop = 197 ppm 12 drop = 215 ppm 13 drop = 233 ppm 14 drop = 251 ppm 15 drop = 269 ppm International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 52 of 56 GEOGRAPHY HL Appendix 11: Evaluation of WQI WQI is not designed for tropical climates, therefore it is important to understand its limitations when applying NSF’s water quality standard to tropical rivers which tend to contain have a higher temperature, sediment load (and thus SS, BOD, FC and nutrients) and slower speed. The following graphs show that streams in Iowa, a place with a temperate climate, have seasonal trends. Seasonal WQI trends of rivers in Iowa44 The same streams with nearly 69% good WQI and some medium WQI, flips over to over less than 30% good WQI in the summertime. This change may be an indicator of the increase in animal or human use of the streams for transportation or leisure during this season, or else, it could indicate that it is the temperature change which greatly affected the WQI. Summertime in Iowa is on average 26.745 near the average temperature of sites tested in this investigation: 28.76. This data suggests that it is possible that in tropical rivers, its high temperature may lower the WQI of what may be in fact a ‘good’ quality river. So for tropical rivers perhaps temperature should have less weight. It could also be argued that given the conditions of an LEDC, such as Cambodia where river water is used for drinking without treatment, that the weight for FC should be much higher. So a WQI that would indicate good quality in Cambodia, may in fact, if used for the same purposes in temperate climates, be of excellent quality, since water in MEDCs is generally treated further before usage. Finally, the WQI has been designed to give a general overview of water quality, assigning weights to the different factors in order of most harm or benefit to humans. It should not be viewed as the ultimate indicator of water quality since water is used for a variety of different purposes, e.g. drinking, cooking, bathing, fish raising, agricultural irrigation, recreation (such as fishing, sailing, swimming), or industrial use. The following table compares the World Health Organization’s guidelines for drinking water with Cambodia’s actual average drinking water quality. Indicator Unit WHO guidelines Cambodia standard Colour Pt/Co 15 5 pH value Unit 6.5 – 8.5 6.5 - 8.5 Suspended solids Mg/L 1 Turbidity NTU 5 5 Total dissolved solids Mg/L 1000 800 Dissolved oxygen Mg/L <10 Total coliform Cfu/100ml 0 0 Fecal coliform Cfu/100ml 0 0 N-Ammonia (NH3-N) Mg/L 0.05-0.50 Source: Phnom Penh Water Supply Authority, 2006 This table indicates that much processing is done after retrieving water from a source, so the value of the WQI of rivers on its own is less significant than if compared with other standards. It is useful in comparing tropical rivers against other tropical rivers, but should not be considered as the ultimate water quality standard, nor should tropical rivers’ WQI be compared with temperate rivers since they are different, and appropriately, should have different standards. 44 45 Water Quality Index: Iowa. The Iowa Department of Natural Resources. http://wqm.igsb.uiowa.edu/wqi/wqi.asp 11/02/07 WELCOME TO PROJECT CHILDREN. http://www.projectchildrenni.com/states.htm 11/02/07 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 53 of 56 GEOGRAPHY HL Appendix 12: Raw Data Information was collected from the 5 sites, every month from August to May. From the dry season’s set of data, I decided to use the following, since they were not prone to be affected by the reversal of the river flow: Sample 1: January 13, 2007 Test Secchi (cm) pH Hardness (ppm) Temperature (°C) Nitrate (ppm) Phosphate (ppm) Dissolved Oxygen (ppm) Dissolved Oxygen in 5 days (ppm) Biological Oxygen Demand (ppm) Dissolved Oxygen (%) Dissolved Solids (ppm) Suspended Solids (ppm) Total Solids (ppm) Turbidity (NTU) E. coli (colonies/100 ml) Water Quality Index (WQI) Sample 2: February 17, 2007 Site 2 Site 4 Tonlé Sap Mekong 19.69 39.37 7 7 54 54 30.5 30.7 <0.1 <0.1 <0.1 <0.1 5 6 3 4 2 2 66 79 60 130 10 5 70 135 17 8 400 200 64 68 Site 2 Tonlé Sap 30 7 36 27.2 < 0.1 0.1 6 4 2 73 60 30 90 22 1050 73 Site 4 Mekong River 70 7 54 26.8 < 0.1 < 0.1 7 5 2 85 120 12 132 11 500 77 Test Secchi pH Hardness Temp Nitrate Phosphate Dissolved Oxygen DO (5 days) BOD DO Dissolved Solids Suspended Solids Total Solids Turbidity E. Coli Water Quality Index Units inches pH ppm °C ppm ppm ppm ppm ppm % ppm ppm ppm NTU /100ml WQI International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 54 of 56 GEOGRAPHY HL For the wet season, I decided to use the following, for the same reasons: Sample 1: August 26, 2007 Test Secchi (cm) pH Hardness (ppm) Temperature (°C) Nitrate (ppm) Phosphate (ppm) Dissolved Oxygen (ppm) Dissolved Oxygen in 5 day (ppm) Biological Oxygen Demand (ppm) Dissolved Oxygen (%) Dissolved Solids (ppm) Suspended Solids (ppm) Total Solids (ppm) Turbidity (NTU) E. coli (colonies/100mL) Water Quality Index Sample 2: September 30, 2007 Test Secchi pH Hardness Temp Nitrate Phosphate Dissolved Oxygen DO (5 days) BOD DO Dissolved Solids Suspended Solids Total Solids Turbidity E. coli Water Quality Index Units inches pH ppm °C ppm ppm ppm ppm ppm % ppm ppm ppm NTU /100ml WQI Site 2 Tonlé Sap 17.72 7 36 28.9 <0.1 <0.1 5 3 2 64 60 10 70 20 1100 Site 4 Mekong 7.87 7 36 28.6 0.1 0.1 5 3 2 63 70 180 250 42 2100 Site 2 Tonlé Sap 2.2 8 72 29 < 0.1 0.2 7 3 4 90 60 200 260 90 1000 68 Site 4 Mekong River 2.2 7 36 28.4 < 0.1 < 0.1 7 3 4 88 60 200 260 90 750 69 70 66 International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 55 of 56 GEOGRAPHY HL Appendix 13: Standard Deviation Tonlé Sap River Standard Deviation 1.0 4.5 1.3 Standard Deviation Mekong River Standard Deviation 1.5 4.5 3.0 Water Quality Index Wet Season Samples Dry Season Samples Average Calculating the standard deviation (SD) of the results do not indicate whether or not the results are reliable because although the SD values suggest that the average differences between each measurement can be attributed to chance, repeated measurements at each site within each month were not taken, so these variations can also be attributed to the seasonal changes occurring in the time between when Samples 1 and Samples 2 were taken. Appendix 14: Temperature It wasn’t possible to calculate temperature change (the difference of one site’s temperature to the temperature of a site further upstream on the same river), for Site 4 on the Mekong (because we did not measure a site upstream from Site 4) so this calculation was not done for the Tonlé Sap’s Site. Although calculations for DO directly involved the temperature measurements, the calculated WQI does not take into account temperature change. International School of Phnom Penh (ISPP) Candidate Name: PAN Nettra Danette Candidate Number: 001222-011 1222 Page 56 of 56 GEOGRAPHY HL 2007 © Nettra Pan Two fishing boats on the Mekong River in Phnom Penh during the rainy season.