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

i

11

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

49

49

49

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51

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52

53

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

64

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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60

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. 76

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viii

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,

3

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,

4

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

5

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

6

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

7

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).

8

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.

10

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

14