Post on 05-Jun-2019
WATER QUALITY ASSESSMENT OF TRUSAN AND LIMBANG BASINS, SARAWAK
Tie Siaw Tze
Master of Environmental Science (Land Use and Water Resource Management)
2010
Pusat Khidmat Mak)uroat Akademik t 1NIVERSTTI MALAYSIA SARAWAK
P, KMIDMAT MAKLUMAT AKADäMIK
111111111111 ril 11 Il III III 1000248307
WATER QUALITY ASSESSMENT
OF TRUSAN AND LIMBANG BASINS, SARAWAK
TIE SIAW TZE
A dissertation submitted
in fulfillment of the requirement of the Master of Environmental Science
(Land Use and Water Resource Management)
Faculty of Resource Science and Technology (FSTS)
UNIVERSITI MALAYSIA SARAWAK
2010
ACKNOWLEDGEMENTS
Acknowledgements are owned to a number of people. First and foremost, I would like
to record my sincere gratitude and appreciation to my study supervisor, Dr Lim Po Teen
for his unwavering support and invaluable advice in getting this research completed. An
appreciation to Dr Lau Seng who gave valuable comments and suggestions.
In particular, I wish to accord my appreciation to the management of ECOSOL
Consultancy Sdn Bhd for the support on my study leave and assistance in this project.
All the colleagues who always shared their knowledge and assisted me in drafting some
of the figures and maps are also gratefully acknowledged.
I also would like to record my special thanks to all SLUSE 8`h Cohort lecturers, resource
persons, coordinator and my coursemates. Sincerely thanks for their encouragement,
invaluable knowledge and experiences.
Last but not least, I would like to acknowledge the encouragement given by my family,
particularly my parents
i
ABSTRACT
Good Land-use practice or land and water resources management is the key remediate
water quality in our rivers for sustainable water resources. This study is to determine the
water quality status in the Limbang and Trusan basins comprised of Limbang River,
Selidong River, Medamit River and Batang Trusan. Water parameters included pH, DO,
BOD5, COD, TSS, Ammoniacal nitrogen, TFC and TCC were examined. Selidong
River and Limbang River are comparatively more polluted than Sungai Medamit and
Batang Trusan. Study showed that the mean annual soil loss, E, from bare Kapit soils on
30-degree slopes, were estimating to be 44,283 mt/ha/yr of contribution by logging,
development and agricultural activities at the hilly areas. When the slopes of the areas
are getting higher, the mean annual soil loss was calculated to get higher as well.
Similarly, once the area been developed or cleared, the topsoil was stripped and the
more erodable subsoil exposed; thus, the mean annual soil loss would increase
dramatically.
ABSTRAK
Pengurusan air dan tanah dengan baik adalah kunci bagi meningkatkan kualiti air dalam
sungai-sungai kita untuk jangka masa panjang sumber air. Pemeriksaan kualiti air dalam
Limbang dan Trusan lembangan termasuk Sungai Limbang, Sungai Selidong, Sg
Medamit dan Batang Trusan. Parameter yang terlibat termasuk pH, DO, BOD5, COD,
TSS, nitrogen Ammoniacal, TFC dan TCC. Sungai Selidong dan Sungai Limbang
adalah lebih tercemar daripada Sungai Medamit dan Batang Trusan. Kajian juga
menunjukkan kadar-kadar hakisan tanah dijangka mencapai 44,283 mt/ha/yr berpunca
daripada pembalakan, pembangunan dan aktiviti-aktiviti pertanian pada kawasan bukit
tinggi. Apabila lereng-lereng bagi kawasan itu menjadi semakin tinggi, makna
kehilangan tanah tahunan akan meningkat juga. Serupa, bila kawasan pembangunan
dan penerokaan secara besar-besaran, tanah yang telah dilucutkan akan mendedahkan
subtanah; makna kehilangan tanah tahunan akan meningkat secara mendadak.
III
Pusat Khidmat Maklumat Akadereil, UW"F'$(iT MALAYSIA SAkAWAK
TABLE OF CONTENTS
ACKNOWLEDMENT
ABSTRACT
ABSTRAK
TABLE OF CONTENTS
LIST OF FIGURES
LIST OF TABLES
CHAPTER ONE INTRODUCTION
Page
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111
iv
vii
viii
CHAPTER TWO LITERATURE REVIEW 6
2.1 INTRODUCTION 6
2.2 WATER RESOURCES RELATED ISSUES IN MALAYSIA 10
2.3 GUIDELINES FOR MANAGEMENT OF WATER CATCHMENT
AREAS IN SARAWAK 12
2.4 NATIONAL WATER QUALITY STANDARDS (NWQS) FOR
MALAYSIA 13
2.5 WATER QUALITY PARAMETERS 14
2.6 QUALITY CONTROL PROCEDURES IN FIELD 29
2.7 NUTRIENT LOSSES IN THE OIL PALM PLANTATION 30
2.8 WATER QUALITY AND THE ENVIRONMENT 31
2.9 SOIL EROSION 34
iv
2.10 PROGRESS STUDY IMPLICATIONS FOR SOIL
CONSERVATION MEASURES IN TROPICAL STEEP LANDS 38
2.11 CLIMATE 39
2.12 POLLUTION SOURCES 40
2.13 ENVIRONMENTAL PERSPECTIVE IN AGRICULTURE 42
2.14 ENVIRONMENTAL POLICY IN MALAYSIA 43
2.15 STRATEGIES TAKEN BY THE GOVERNMENT TO IMPROVE
RIVER WATER QUALITY 44
2.16 INTEGRATED CATCHMENT MANAGEMENT (ICM) 45
CHAPTER THREE MATERIALS AND METHODS 47
3.1 STUDY AREA 47
3.2 HYDROLOGIC DATA ANALYSIS
3.3 WATER QUALITY ANALYSIS
3.3.1 SAMPLING FREQUENCY
3.3.2 PHYSICO-CHEMICAL PARAMETERS
3.3.3 SAMPLING PROCEDURE AND PRESERVATION
3.3.4 ANALYTICAL METHODS
3.3.5 CLASSIFICATION OF THE WATER QUALITY
3.4 LAND USE ANALYSIS
3.5 SOIL EROSION MODELLING
49
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V
CHAPTER FOUR RESULTS AND DISCUSSION
4.1 HYDROLOGIC DATA
4.2 WATER QUALITY ANALYSIS
4.3 STATUS OF RIVER WATER QUALITY
4.4 GENERAL SETTLEMENT PATTERNS AND REGIONAL LAND
USE
4.5 SOIL EROSION MODELLING
4.6 SOURCES OF POLLUTANTS
54
54
59
64
71
74
77
CHAPTER FIVE CONCLUSIONS AND RECOMMENDATIONS 83
5.1 CONCLUSIONS 83
5.2 RECOMMENDATIONS 85
REFERENCE 88
APPENDIX 1 WATER QUALITY AND EFFLUENT DISCHARGE
STANDARDS 93
V1
LIST OF FIGURES
Figure 1.1
Figure 3.1
Figure 4.1
Figure 4.2
Figure 4.3
Figure 4.4(a)
Figure 4.4(b)
Figure 4.4(c)
Figure 4.4(d)
Figure 4.4(e)
Figure 4.4(f)
Page
The Northern interior of Sarawak. Noted that Limbang River flows 2
from the Batu Lawi Mountain and Murud Mountain area
Location of the Water Sampling Points
Locations of Rainfall Stations
Mean Monthly Average Rainfall from Available Stations
Source: Department of Irrigation and Drainage
Yearly Evaporation Data from 1983 - 2004
pH levels of the Medamit, Selidong, Limbang and Trusan Rivers
DO levels of the Medamit, Selidong, Limbang and Trusan Rivers
BOD levels of the Medamit, Selidong, Limbang and Trusan Rivers
COD levels of the Medamit, Selidong, Limbang and Trusan Rivers
TSS levels of the Medamit, Selidong, Limbang and Trusan Rivers
Amm. N levels of the Medamit, Selidong, Limbang and Trusan
Rivers
Figure 4.4(g) Faecal Coliform Count levels of the Medamit, Selidong, Limbang
and Trusan Rivers
Figure 4.4(h) TCC levels of the Medamit, Selidong, Limbang and Trusan Rivers
Figure 4.5 Catchment Land Use Distribution
48
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56
58
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65
66
67
68
69
70
71
72
Figure 4.6 Land uses within the Water Sampling Points Catchments 82
vii
LIST OF TABLES
Table 3.1 Locations of the Water Sampling Points
Table 3.2 Water Quality Parameters that Were Examined
Table 3.3 Special Sampling or Handling Requirements
Table 4.1 Available Rainfall Stations
Table 4.2 Mean Monthly Rainfall
Table 4.3 Physical, Chemical and Biological Data Collected from Limbang
and Trusan Basins during March 2008 and March 2009
Table 4.4 Land Uses within Catchment
Table 4.5 Cropping Management factors
Table 4.6 Potential Soil Erosion (mt/ha/yr)
Table 4.7 Sediment rates of Limbang River
Paae
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57
60
72
. 76
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CHAPTER ONE
INTRODUCTION
Water is a valuable resource that all the biological life depends on for securing the
necessities of life; as well as for humanity's needs for drinking, horticulture, agriculture,
industry, recreation and wetlands maintenance. However, clean potable water is getting
scarce and unavailable to million of people each day. Only 1% of the world's water is
for all biological life, as nearly 97% is salty and another 2% is locked in ice caps and
glaciers and the remaining areas of two rivers.
In the Northern interior of Sarawak, the Limbang River flows from the Batu Lawi
Mountain and Murud Mountain area (Figure 1.1). It is noted that the elevation gets
higher as one goes farther inland, rising to a height of 7,950 feet. From its headwaters,
the Limbang River flows north-westwards through the Limbang Division, navigable for
about 210 km and eventually discharging into the Brunei Bay. The drainage pattern in
the headwaters is considered as trellis and rectangular, reflecting the strong structural
geological elements in the region. Limbang River serves as the main linkage for cargo
and passenger vessels communicating mainly between Limbang, Brunei and Labuan.
1
36 MEIL"! AU PARU
MM DIVISION
Figure 1.1 The Northern interior of Sarawak.
BT BATU LAWI
SCALE 1: 750,000
CATCHMENT BOUNDARY
DIVISIONAL BOUNDARY
XXk INTERNATIONAL BOUNDARY
DISTRICT BOUNDARY
STATE BOUNDARY
TOWN/SETTLEMENT
2
The Lawas District is situated at the northern end of Sarawak, which sandwiched
between Brunei Darussalam and Sabah. Trusan Town itself is about 16 km from Lawas
Town, via the tar-sealed Lawas-Trusan Road. Ferry service at Trusan Town is the
present mode of crossing Batang Trusan, to go to Brunei and then Limbang. Batang
Trusan is approximately 100 m wide at the current ferry crossing. Batang Trusan
originates from the Maligan Highland, flowing in a northerly direction into the Bay of
Brunei. The Trusan catchment has an area of over 2,300 km2.
With the rapid development and increasing of human populations, the demands for
higher water capacity and quality have increased. However, hydrological problems
related to non-natural and natural changes in the quality of inland water bodies. In other
words, human activities have changed water composition. These activities commonly
included uncontrolled clearing of forests and natural vegetation for agriculture
activities; timber harvesting; excessive use of fertilizers and pesticide for agricultural
purposes; runoff from urban areas such as housing, commercial and industrial. Each
water use, including abstraction of water and discharge of wastes, has long-term effects
on ground and surface water resources.
Due to the isolated locations of the some settlements along the upper rivers, the most
unsatisfactory situation pertains to domestic waste disposal, with waste being just
thrown into river. Domestic sewage and wastes include plastic materials, glass, kitchen
wastes, etc. Such pollutants may be carried away as floating rubbish in the rivers or may
sink and block the flow of the rivers. If these materials were not properly disposed of,
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they would be aesthetically unpleasant, produce odour, become breeding grounds for
pests and diseases, and even present physical safety hazards.
Human activities that involve clearing of land along the waterways may also cause
vegetative debris and solid wastes such as leaves, tree trunks and branches, roots, etc., to
washout by rain and eventually litter the waterways. Other than that, in the hilly areas,
clearing of land will expose the land surface directly to erosion elements. The cutting of
terraces will loosen, disturb, turn and move the soils on the slopes and thus create slope
instability, especially those with very steep gradients. As a result, slopes may fail and
collapse, and contribute to soil loss from the slopes. Loosened soils will be washed by
rain into the waterways causing high loading sediment in the waters.
Excessive and inappropriate applications of fertilisers also cause undesirable impacts.
Nitrogen as one of the common fertilizers is applied in the form of urea, ammonium, or
nitrate compounds. Nitrate, being soluble in water and negatively charged can easily
find its way into the water sources. Eutrophication, it will naturally promote the growths
of plants, whether desirable or undesirable. If the nitrate were to get into the streams and
rivers in large quantities, it would promote the excessive growth of aquatic micro-flora.
Agro-chemicals such as fertilizers, herbicides and other biocides are potent pollutants
that could cause significant impacts if they are not carefully managed and used. The
quality of surface and ground water may be affected if leaching of agro-chemical
applied to the field occurs. If large quantities of fertilisers get into the watercourses,
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Pusat Khidmat Maklumat Akademik UNIVERSITt MALAYSIA SARAWAK
they may cause eutrophication of the water systems. Pesticides are also highly toxic to
the aquatic ecosystem, fauna elements and humans who depend on the water directly.
Undeniably, human activities have brought degradation of our water resources.
Therefore, good land and water management is the key to improve water quality in our
rivers for long term sustainable water resources. Assessment of the quality of water is
the first steps towards successful management.
In this study, status of Limbang and Trusan Basin was assessed in existing physical-
chemical environment. The main objective of this study thus is to examine the water
quality status through several water parameters in relationship to the land use pattern in
the area. Information obtained from this study could be used for management of the two
river basins and conservation of water resources.
The specific objectives of this study are:
" To assess and establish "baseline" data of the water quality of these rivers;
" To identify specific existing or emerging water quality issues;
" To identify the types of pollutants discharged into the rivers;
" To identify the possible sources of pollutants; and
" To gather information and make recommendations for follow-up action to
maintain and improve water quality of the rivers
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CHAPTER TWO
LITERATURE REVIEW
2.1 INTRODUCTION
Water pollution is caused by any human's activities such as urbanization,
industrialization, population growth, and the expansion of irrigated agriculture
(Moduying and Gabriel, 2004) that subsequently reduce the usefulness of water to
humans as well as organisms in nature. Nowadays, water pollution is of concern and
the common pollutants include herbicides, pesticides, fertilizers, hazardous chemicals
(EPA, 1997), organic loads (BOD), sediments and bacterial loads (Moduying and
Gabriel, 2004). According to WRC (2008), about two million tons of wastes are
dumped every day into rivers, lakes and streams. It should be notable that one liter of
wastewater pollutes eight litres of freshwater.
Apart from industries, most of Sarawak's 2.2 million hectares of arable land and 1.7
million hectares of peat soil located in the region had been developed into agricultural
sector. The State, which has the largest forest area in Malaysia, has set aside 7.5 million
hectares for Permanent Forest Estates (PFEs) and Totally Protected Areas (TPAs). The
acreage for the Palm Oil Industry could potentially grow from 400,000 hectares to 1
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million hectares. Sarawak holds 7.6 million hectares of log-able forests (44% of
Malaysia), contributing to 26% of its GDP. Forest plantations in Sarawak are currently
below 1 million ha. Total potential for forest plantations is 3.4 million ha (State
Government of Sarawak, n. d. ).
In an effort to sustain the timber industry while at the same time conserve the remaining
forests; the State Government has therefore encouraged the timber companies in
Sarawak to practice sustainable forest management. To this end, a total of one million
hectares of land has been earmarked for forest plantation development. The underlying
rationale for establishing the forest plantations is that the land can be continuously
cropped to provide sustainable and reliable sources of raw materials for the timber mills,
medium-density fiberboard (MDFB) factories and other wood-based manufacturing
plants (ECOSOL, 2009a).
At both the national and State levels, the importance of agriculture in terms of its
contribution to the Gross Domestic Product and its level of employment is indisputable.
Since the First Malaysian Plan (1965-1970), agriculture has always featured
prominently in the development plans. Under the Ninth Malaysian Plan, agriculture has
been termed the third engine of growth after the manufacturing and service sectors.
Palm oil is a key agricultural commodity, and, is the leading global source of vegetable
oil. The increasing demand for oil and hence this commodity stems from increasing
food consumption in developing countries, particularly China and India. Malaysia and
Indonesia has already expanded its area under oil palm areas very rapidly in the last
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three decades growing by 12 per cent annum to 7.1 million hectares in 2008 (Gan,
2009).
At present, Malaysia is one of the world's largest producers and exporters of palm oil,
oleo-chemicals and other related products. Oil palm cultivation within the framework of
economy viability usually involves enormous tracts of land. There is a growing concern
that this type of large-scale agriculture could lead to many of the environmental ills
similar to what the other economic sectors would do. Land degradation and loss of peat
swamp ecosystems are major concerns. Agro-chemicals including chemical fertilisers
and synthetic pesticides, some of which have become an integral and indispensable
component in the plantation industry, are liable to cause such negative side effects as
water pollution. Excessive nitrate leaching into the surface and ground water, and the
persistence of pesticide residues polluting soil and water are all of environmental
concern (ECOSOL, 2009b).
Other than that, environmental non-government organizations (NGOs) have alleged that
expansion of oil palm agriculture in Malaysia and Indonesia has destroyed huge tracts of
tropical forest and threatened the survival of many native species, including the
orangutan (Pongo pygmaeus and P. abelii), tigers (Panthera tigris sumatrae), Sumatran
rhinoceros (Dicerorhinus sumatrensis) and Asian elephants (Elephas maximus) (Gan,
2009).
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In the last few decades, Sarawak has experienced relatively strong economic growth.
The forestry sector has been the major contributor to Sarawak's economy; second only
to petroleum and other related products of petroleum. The outlook for the timber
industry usually depends on demand from major markets such as Japan, Europe and the
United States. In 2007, the export of timber and timber products totalled RM 22.65
billion. Wooden furniture exports accounted for 29.3% of the total value while plywood
contributed 27.7% (or RM 6.27 billion) to the total revenue earned. For Sarawak alone,
the revenue from timber exports was RM7.74 billion, which was 34% of the national
total. It contributed about 12% to the external trade revenue of Sarawak, the third largest
contributor after gas and petroleum.
The continual success of the forestry sector as a major economic generator will depend
on the sustainable utilization and management of the production forests. The selective
poly-cyclic harvesting technique is one of the forest management practices that have
been adopted by the Forest Department, Sarawak (FDS) and SFC to ensure the
sustainability of this important natural resource. This is in support of the Government's
obligation under international treaties such as the International Tropical Timber
Agreement, the Biodiversity Convention and the Framework Convention on Climate
Change (ECOSOL, 2009c).
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2.2 WATER RESOURCES RELATED ISSUES IN MALAYSIA
Based on the study by the Gabriel and Moduying (2004), in 2002, the major pollutants
for rivers in Kota Kinabalu are sedimentation of rivers, wastewater discharge, solid
waste from industries and livestock rearing. In upper Bandau water catchments, much of
the deterioration was related to the vegetation removal and road construction on steep
areas, which associated primarily with agricultural development and logging. These
activities are set to reinitiate large scale erosion and sedimentation of rivers and
floodplains downstream.
Similarly, logging and clearance of land for agriculture in the upper Padas River
catchment is probably one of the main causes of the apparent increase in number of
flood events over the years. Large amount of suspended sediments in the river is a major
factor in creating water quality problems in the various water supply treatment plants,
irrigation pumping stations and the Tenom Pangi Hydropower Station.
Sungai Padas, Sungai Pegalan and its smaller tributaries are used as sources of water
supply for the population within the Padas River catchment. Water for the main towns is
provided with a standard surface water treatment including chlorination before
distribution. However, villages outside the town areas or the reticulation system,
however, use river water directly from the sources. There is a growing concern that the
increasing amount of domestic and industrial wastewater, pesticides and fertilizer
ending up in the rivers.
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In the report of the Regip. et. al. (2004) stated that, water quality in the Kinabatangan
and its tributaries has been declining since the 1960's when commercial' logging started
in the upper river catchment and worsened in the 1980's when the oil palm plantations
and mills started operations. The main pollution sources in the Kinabatangan River
catchment now are effluent from palm oil mills, pesticides, and fertilizers; sediment
from plantations, sediment from logging activities and sewage from villages along the
river (Regip et. al., 2004).
Land clearing for plantations and logging are the main source of sediment into the
Kinabatangan. The total sediment transport by the Kinabatangan River is about 6
million tones per year. The majority of the sediment originates from the hilly upper
catchments, which is largely forested but with significant areas of plantation crops.
Significant impacts can be felt downstream, where the great majority of the floodplain
has been converted to plantation agriculture and other cash crops, or village settlements.
Increased sediment load has also led to geo-morphological changes such as increased
riverbank erosion. Sediment transport in a large river system like the Kinabatangan has
large time-lags built-in, meaning that even if all logging activities and land clearing
were to stop immediately, the sediment loads in the river may only decline after 5- 10
years. This is the time required to transport away all the previously deposited sediment,
both in the river channels as well as on the catchments slopes.
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2.3 GUIDELINES FOR MANAGEMENT OF WATER CATCHMENT
AREAS IN SARAWAK
In Sarawak, there are some clear provisions in the laws that are related to the
management of Water Supply Catchment areas such as those provided in the Water
Ordinance 1994, Natural Resources and Environment Ordinance 1993 and Sarawak
Rivers Ordinance 1993 (Tay, 2004). There are other laws that do not have explicit
provisions on the management of water catchment areas but they have certain
provisions which have a bearing on the management of catchment areas. These laws
include the Forest Ordinance 1954, Local Authority Ordinance 1996, Land Code 1958
and the Sarawak Inland Fisheries Ordinance 2003 (Tay, 2004). The management of
water catchment areas in Sarawak is most extensively covered under the Water
Ordinance.
Water Ordinance 1994
The Water Ordinance was amended in 2000 and cited as the Water (Amendment)
Ordinance 2000. The Water Ordinance 1994 has clear provisions relating to the
management of water supply catchment areas. At present, in Sarawak, these provisions
in the Water Ordinance 1994 are relied upon for the management of Water Catchment
Areas.
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Sarawak Water Resources Council
Part II Section 3 of the Water Ordinance provides for the establishment of the Sarawak
Water Resources Council (SWRC). SWRC was set up in 1991 to pursue a more
effective water management.
2.4 NATIONAL WATER QUALITY STANDARDS (NWQS) FOR
MALAYSIA
The National Water Quality Standard for Malaysia (NWQS) is one of the relevant water
quality and effluent discharge standards:
Classes Parameters Units
I IIA LIB III IV V
pH 6.5-8.5 6-9 6-9 5-9 5-9
DO mg/l 7 5-7 5-7 3-5 <3 <1
BOD5 mg/i 1336 12 > 12
COD mg/i 10 25 25 50 100 > 100
Ammoniacal mg/l 0.1 0.3 0.3 0.9 2.7 > 2.7
Nitrogen
T. S. S. mg/l 25 50 50 150 300 >300
F. Coliform ** counts/ 100m1 10 100 400 5000 5000
20000' 20000'
Total Coliform counts/100ml 100 5000 5000 50000 50000 >50000
** 1- Maximum not to be exceeded Source: NREB, 1995b
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2.5 WATER QUALITY PARAMETERS
The various parameters represent the following (UNESCO, WHO and UNEP, 1996):
Dissolved Oxygen (DO)
Dissolved Oxygen (DO) is a measure of the amount of available oxygen dissolved in the
water sampled. The DO level is essential for the survival of aerobic micro-organisms
and other aquatic life form.
The oxygen content of natural waters varies with temperature, salinity, turbulence, the
photosynthetic activity of algae and plants, and atmospheric pressure. The solubility of
oxygen decreases as temperature and salinity increase. In fresh-waters dissolved oxygen
(DO) at sea level ranges from 15 mg/l at 0° C to 8 mg/l at 25° C. Concentrations in
unpolluted waters are usually close to, but less than, 10 mg/l. Dissolved oxygen can also
be expressed in terms of percentage saturation, and levels less than 80 per cent
saturation in drinking water can usually be detected by consumers as a result of poor
odor and taste.
Variations in DO can occur seasonally, or even over 24 hour periods, in relation to
temperature and biological activity such as photosynthesis and respiration. Biological
respiration, including that related to decomposition processes, reduces DO
concentrations. In still waters, pockets of high and low concentrations of dissolved
oxygen can occur depending on the rates of biological processes. Waste discharges high
in organic matter and nutrients can lead to decreases in DO concentrations as a result of
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