THE IMPACT OF SEJINGKAT COAL-FIRED POWER

PLANT ON THE WATER QUALITY OF SARAWAK RIVER

ANITA BRUIN

A thesis submitted in partial requirements for the

Master of Environmental Science

(Land Use and Water Resource Management)

Faculty of Resource Science and Technology

UNIVERSITI MALAYSIA SARAWAK

2006

This dissertation is dedicated with love and gratitude to

My husband:

Harold Frederick Law

And

My daughter:

Nathalie Faith Law

ACKNOWLEDGEMENT

Many are to be thanked for this; by God's almighty for giving me strength. First

and foremost, I would like to express my deepest gratitude and appreciation to my

supervisor, Dr. Lee Nyanti for his dedication, criticism and guidance throughout the

preparation of this dissertation, for without him, this study would not have been

successful.

I would also like to extend my profound gratitude and appreciation to the people of

SLUSE Master Programme and all my course mates especially Tracy, Semuel, Jubin,

Hamden, Easter Storie and Khamri for their kindness. Special thanks also to Mr.

Rajuna Tahir for helping me during the sampling trip.

Finally, I would like to dedicate my deepest gratitude and love to my beloved

husband and my daughter for their understanding, blessings and endless

encouragement throughout my study. Last but not least thanks also to my parent,

sisters, relatives, and friends for their support and encouragement. The study would

not been possible without them.

Anita Bruin

II

2006

~sat Khidmat Maklumat Akademik fVEItS'Tl ~,f.4.f 'Vt;'. S.-IItAWAK

TABLE OF CONTENTS

Page

Dedication 1

Acknow ledgement 11

Table of Contents 111

List of Tables VI

List of Figures vii

List of Appendices ix

Abstract x

Abstrak xi

CHAPTER 1 INTRODUCTION

1.1 Background of Sejingkat Coal-Fired Power Plant 1

1.2 Scope of Study 3

1.3 Justification of Study 3

CHAPTER 2 LITERATURE REVIEW

2.1 Coal Utilization 5

2.2 Thermal Pollution 6

2.3 Water Quality Parameters 8

2.3.1 Physical Variables 8

2.3.1.1 Temperature 8

2.3.1.2 Turbidity 10

2.3.1.3 Total Suspended Solids (TSS) 11

III

2.3.1.4 Salinity 11

2.3.1.5 Conductivity 12

2.3.2 Chemical Variables 12

2.3.2.1 Dissolved Oxygen (DO) 12

2.3.2.2 Biochemical Oxygen Demand (BOD5) 13

2.3.2.3 Chemical Oxygen Demand (COD) 14

2.3.2.4 pH 15

2.3.2.5 Nutrient Contents 16

2.3.2.5.1 Ammoniacal - Nitrogen (NH3-N) 16

2.3.2.5.2 Nitrate-Nitrogen (N03-N) 16

2.3.2.5.3 Orthophosphate (P043.) 17

2.4 Water Quality Index (WQI) 17

2.5 Water Quality Classification 18

CHAPTER 3 MATERIALS AND METHODS

3.1 Study Site 19

3.2 Parameters Collected in the Field 21

3.2.1 In situ measurement 21

3.2.2 Water Samples Collection 21

3.3 Parameters Measured in Laboratory 25

3.3.1 Biochemical Oxygen Demand (BOD5) 25

3.3.2 Chemical Oxygen Demand (COD) 25

3.3.3 Total Suspended Solids (TSS) 26

3.3.4 Nutrient Analysis 26

3.3.4.1 Ammoniacal-Nitrogen (NH3-N) 27

IV

3.3.5

3.3.4.2 Orthophosphate (P043.)

3.3.4.3 Nitrate·Nitrogen (N03.-N)

Quality Control

27

27

28

CHAPTER 4 RESULTS AND DISCUSSION

4.1 Water Parameters

4.1.1 Temperature

4.1.2 Turbidity

4.1.3 Total Suspended Solids (TSS)

4.1.4 Salinity

4.1.5 Conductivity

4.1.6 Dissolved Oxygen (DO)

4.1.7 Biochemical Oxygen Demand (BOD5)

4.1.8 Chemical Oxygen Demand (COD)

4.1.9 pH

4.1.10 Ammoniacal-Nitrogen (NH3-N)

4.1.11 Nitrate-Nitrogen (N03.·N)

4.1.12 Orthophosphate (P043-)

4.2 Water Quality Indices

29

29

31

33

34

35

36

38

39

40

42

43

44

45

CHAPTER 5 CONCLUSION 47

REFERENCES 49

II, APPENDICES 56

v

LIST OF TABLES

Table 1: Classification of BOD water. 14

Table 2: The coordinates and study site description for each

water sampling station. 24

Table 3: Average Water Quality Indices (WQI) for all the sampling

stations at low tide and mid high tide. 46

f

VI

LIST OF FIGURES

Figure 1:· Map showing the study site of the Coal-Fired Power

Plant at Kg. Goebilt, Sarawak River. 20

Figure 2: Map showing the locality of sampling points. 23

Figure 3: Temperature value recorded at all sampling stations. 30

Figure 4: Turbidity values recorded at all sampling stations. 31

Figure 5: Total Suspended Solids values recorded at all

sampling stations. 33

Figure 6: Salinity values recorded at all sampling stations. 34

Figure 7: Conductivity values recorded at all sampling stations. 36

Figure 8: Dissolved Oxygen values recorded at all sampling stations. 37

Figure 9: Biochemical Oxygen Demand values recorded at all

sampling stations. 38

Figure 10; COD values recorded at all sampling stations. 40 ,:.

Vll

I

Figure 11: pH values recorded at all sampling stations. 41

Figure 12: Ammoniacal-Nitrogen values recorded at all sampling

stations. 42

Figure 13: Nitrate-Nitrogen values recorded at all sampling stations. 43

Figure 14: Orthophosphate values recorded at all sampling stations. 44

viii

LIST OF APPENDICES

APPENDIX 1: MALAYSIAN INTERIM WATER QUALITY STANDARD

CLASSIFICATION. 56

APPENDIX 2: METHOD FOR CALCULATION FOR DOE - WQI. 57

APPENDIX 3: GENERAL RATING SCALE FOR WATER QUALITY

INDEX. 58

APPENDIX 4: PROPOSED INTERIM NATIONAL WATER QUALITY

STANDARDS (INWQS) FOR MALAYSIA (DOE, 1994). 59

APPENDIX 5: LIST OF PLATES. 63

IX

~···-l

ABSTRACT

The demand for electricity is clearly associated with population growth. Thus, the

Kuching Coal-Fired Power Plant located at Sejingkat area was built to cater for this

needs. With the operation of Phase II, the impact to the water quality of the

Sarawak River is not known. In view of this fact, studies have been conducted to

evaluate the water quality on the affected river. Generally, the result obtained in

this study showed that the river was classified under Class II during mid high tide

and Class III during low tide (wQI) which is good and moderate respectively.

However, parameter such as turbidity was outside any of the Class listed (INQWS).

Meanwhile, during low tide parameters such as temperature increased slightly from

31.9 to 34.7 °C whereas pH value decreased slightly from 7.9 to 7.6 as compared to

the condition when only Phase I was in operation. The other parameters such as

TSS, BOD and COD were within Class II while parameters such as DO,

ammoniacal-nitrogen, nitrate-nitrogen and orthophosphate were within Class III in

accordance with INWQS. Thus, it is still viable to support the aquatic life.

x

ABSTRAK

Pertambahan jumlah penduduk adalah sangat berkait rapat dengan permintaan

terhadap tenaga elektrik dan seterusnya menambahkan bilangan pembinaan stesen

janakuasa. Stesen Janakuasa Elektrik yang menggunakan arang batu di kawasan

Sejingkat yang kini beroperasi pada Fasa yang kedua sedikit sebanyak

mempengaruhi kualiti air Sungai Sarawak. Oleh yang demikian, satu kajian telah

dilakukan untuk menilai kualiti air di sungai terse but. Secara umumnya, hasil

kajian mendapati kualiti air Sungai Sarawak berada pada Kelas III semasa air

surut manakala pada Kelas II semasa air pasang yang mana masih di dalam

lingkungan kategori baik dan sederhana (WQI). Walau bagaimanapun, parameter

seperti kekeruhan adalah di luar mana-mana kelas yang tersenarai (INQWS).

Parameter seperti suhu didapati meningkat sedikit dari 31.9 ke 34.7 OC dan nilai pH

pula didapati turun sedikit dari 7.9 ke 7.6 berbanding dengan keadaan semasa

stesen tersebut beroperasi pada rasa yang pertama. Parameter yang lain seperti

TSS, BOD dan COD adalah di bawah Kelas II manakala parameter seperti DO,

ammoniacal-nitrogen, nitrate nitrogen dan orthophosphate pula di bawah kategori

Kelas III (lNQWS). Ini menunjukkan yang sungai tersebut masih sesuai untuk

menampung kehidupan akuatik setempat.

Xl

CHAPTER 1

INTRODUCTION

1.1 Background ofSejingkat Coal-Fired Power Plant

Coal is one of the alternative resource to generate electricity besides hydro power,

wind power and nuclear power. Sejingkat Coal-Fired Power Plant (CFP) is the first

and only power station that provides electricity by using coal in Sarawak. Recently

in a media report, after the weekly Cabinet meeting, Chief Minister of Sarawak

announced that there will be another Coal-Fired Power Plant to be set up near the

coal mines between Mukah and Balingian (The Borneo Post, February 24, 2006).

The Sejingkat CFP is located about 27 kilometers from Kuching City and built on a

130 hectares land area by the side of Sarawak River. Coal is supplied mainly from

the coal mine in Merit Pila, Kapit. The annual consumption of coal for Phase 1 and

Phase 2 is estimate to be 744,000 tonnes (EIA Technical Reports, 2002). There are

three villages situated nearby the Sejingkat CFP namely Kampung Goebilt,

Kampung Senari and Kampung Muara Tebas. The communities which are mainly

Malay at the surrounding area earn their living as fishermen.

The power station operates as a base load plant and the electricity produced is sold

to Sarawak Electricity Supply Corporation (SESCO). The power station was

designated to accommodate four units of steam turbine generators of 50MW in

I• phase 1 and 55MW in phase 2 (EIA Technical Report, 2002). The electrical energy

1

is then supplied to the Kuching City and Sejingkat Industrial area, meanwhile, the

supply from the Phase 2 will go into the state grid to cater for the whole state.

There are several processes involved during the operation of fuel (coal) processing

such as fuel combustion and by products, ash disposal system, turbines and

generators, cooling water systems (condensation) and fresh water system (EIA

Technical Report, 2002).

Generally, electricity is produced by the process of heating water in a boiler to

produce steam. The superheated steam at 535 °C produced under tremendous

pressure will flows into turbines, which spins a generator to produce electricity.

Basically, large amounts of water from Sarawak River is needed for the cooling

system which are then discharged back into the river. This may increase the

temperature of the receiving water body from an original seawater temperature of

25 °C to a temperature of about 33 °C in 20 meter radius. With the water

temperature ranging between 25 oC, the increment was calculated to be 7.84 °C

which is well within the Malaysian Standard. Further more, in order to prevent

marine growth fouling (shells and corals), the water will be treated by chlorine

dosing (EIA Technical Report, 2002). Apart from that, as mentioned by Suh (2001),

the cooling water discharges, also contained an unwanted by· product that may

cause harmful effects to the marine environment.

Apart from the Sejingkat CFP, a lot of other development has taken place along the

bank of Sarawak River and the river receives different types of pollutants from

various industries such as Steel Mill, Flour Mill, HDPE Product Factory, and

2

Hardwood and Softboard Factories. All these industries are located mainly In

Sejingkat area.

1.2 Scope of Study

This study focused on the changes in water quality of Sarawak River with the

operation of the second phase of Sejingkat Coal-Fired Power Plant.

1.3 Justification of Study

Besides population growth, economic development is also a major driving force that

leads to the land use changes in most of the developing countries including

Malaysia. The extensive land conversion from forest into other type of land use

may have significant impact on the water quality and resources. For instance,

power plant were often build on estuaries for convenience and economics points of

view because the estuary provide a source of cooling water for the power plant

(Laws, 2000). I I

In VIew of this fact, there is a need to evaluate if there is any significant

relationship or correlation of coal-fired power plant and the water quality of the

Sarawak River. According to the previous study done by Agatha (2005), the Phase

1 of the Coal-Fired Power Plant was found to have several impacts on the

community structure of harpacticoid copepods at the study area. The community

parameters of the harpacticoid copepods were reported to be significantly influenced

by several physico-chemicals and biological environmental parameters. In addition,

3

the study done by Juliana (2002), found out that water temperature significantly

affect the density of macrobenthos at the study area. Apart from that, Agatha

(2005) also reported that the effect of temperature and chlorine were much localized

within the vicinity of the effiuent outlet during the operation of Phase 1. No studies

have been conducted to determine the effect on water quality after the operation of

Phase 2 of the Sejingkat Coal-Fired Power Plant.

4

,.

2.1 Coal Utilization

Coal has been used to produce electricity although not as rapidly as gas and oiL

Coal is burned to produce nearly 60 % of the electricity used, and about 25 % of the

total energy consumed in the United States today. However, the giant power plants

are responsible for about 70% of the total emissions of sulphur dioxide, 30 % of

nitrogen oxides and 35 % of carbon dioxide. The emissions of air pollutants are

arise from the combustion processes, or coal gasification or liquefaction plants

(Botkin and Keller, 2000).

There has been tremendous growth in the usage of coal to generate electricity.

Electricity has displaced the direct use of coal industry as oil-based electricity

generation is uneconomical in comparison with coal. Between 70 % and 90 % of the

total quantity of coal consumed in planned economies is utilized for electricity

generation (Hester, 1983). Globally, this proportion ranges from 70 % in the United

States to 50 % in western Europe and 15 % in Japan (Chadwick et at., 1989).

Besides that, England (1980) added that we are burning more coal than ever

between 75 and 80 million tones a year and will be expected to maintain that level

of consumption for some more years to come. The Industrial Revolution also leads to

rapidly increasing volumes of water used in the cooling processes (Hester, 1983).

And of course, larger industries will discharge larger volumes of heated and noxious

effluents to the nearest body of water.

5

Pusat Khidmat M k lINlVBRSm MA~ lumat Akademik

YSfA SARAWAI(

CHAPTER 2

LITERATURE REVIEW

However, Laws (2000) pointed that the greatest disruption to aquatic systems from

power plant effiuents may be caused by the continual exposure of the organisms to

sublethal stresses rather than the occasional killing of large number of organisms

due to thermal shock, chlorination, or gas bubble disease.

Khalanski and Bordet (1980) stated that chlorine is widely used to treat fouling for

freshwater and marine cooling water system because it acts quickly and relatively

inexpensive but it is highly toxic. They further explained that, chlorine like other

treatment chemicals, its derivative are vital constituents of many thermal

discharges.

A case study at Turkey Point, Biscayne Bay in East Florida showed an adverse

impact on the aquatic fauna when the Florida Power and Light Company (FPL)

built an oil-fIred generator in 1964 and followed by nuclear-powered generators in

1971. The study found that a total area of2.7 km2 was deteriorated. A massive fIsh

kill was caused entirely by elevated temperature resulting from the power plants

cooling water discharges (Laws, 2000).

2.2 Thermal Pollution

About 75 % of the earth's surface is covered by water. Water is the life giver for

every living things and the hydrological cycle is central to human existence. Water

surface is found in the forms of lakes, rivers, streams, oceans and lagoon. People

have understood the importance ofwater for millennia, and yet it is one of the most

abused and over exploited resources in our planets. Water pollution and scarcity

6

have existed throughout history, and remains today, one of humankind's most

intractable problem (Markham, 1994). As an example, heated water discharge from

a power plant can change the temperature of an aquatic environment. Besides

that, the other major sources of surface water contamination are construction,

municipalities, agriculture, and industries. However, according to Baumgartner

(1996) heated water or water containing some contaminant might not be a problem

provided it is rapidly mixed with the surface water and diluted material does not

accumulate over time.

Thermal pollution, also called heat pollution, occurs when heat is released into the

water or air produces undesirable effects. Heat pollution can occur as a sudden,

acute event or as a long term through chronic release. According to Lloyd (1992), .. ~:GESAMP defined marine pollution as "the introduction by man, directly or 1·

" II Iindirectly, of substances or energy (e.g., heat) into the marine environment ~ f

"(including estuaries) resulting in such deleterious effects as harm to living :1

.1 I.resources, hazards to human health, hindrance to marine activities including !

fishing, impairment of quality for use of seawater and reduction of amenities." .'

Cooling water discharges from the electricity generating stations including coal-

fired power plants are the main sources of pollution by heat. Increase in

temperature alters the physical environment, in term of both a reduction in the

density of water and its oxygen concentration. The impact on fish specifically can

be lethal, inhibit the migration, increase susceptibility to disease, reduces

metabolism efficiency and changes in competitive advantage.

r 7

Besides thermal pollution, Laws (2000) stated that aquatic organisms may also be

killed by the discharge of chlorine used to prevent fouling in the heat exchangers.

The toxicity of chlorine plays an important role in the impact of entrainment on the

other types of organisms such as zooplankton. This was supported by Clark and

Brownell (1973), which found out that a number of menhaden at the Cap Pod Canal

Plant in Massachussetts in 1968 and the killing of 40,000 blue crabs at the Chalk

Point Plant in Maryland. He further explained that effluent chlorine

concentrations during intermittent chlorination are typically 0.5-2.0 mgll for a

periods of 20-30 minutes. The criterion maximum concentrations for chlorine are

0.013 mgll for marine water and 0.019 mgll for freshwater (EPA, 1986).

2.3 Water Quality Parameter

2.3.1 Physical Variables

2.3.1.1 Temperature

Water temperature plays an important role as it affect the natural condition of the

ecosystems, and direct or indirectly affects the dynamics of all water quality

variables especially to the temperature dependence of chemical reaction rates,

equilibrium constants, solubility products, gas behavior, and other physicochemical

processes (Boyd and Tucker, 1998).

Heating the water not only changes the natural conditions of the ecosystems but

also affects the fish spawning cycle. susceptibilities to disease, physical stress and

change the type and abundance of food available. Hammer and Hammer (1996).

8

l

further explained that higher temperature in the rIver would also favour

anaesthetic growths of bacteria and fungi or blue-green algae in place of green

species.

The release of large amounts of heated water into the river changes the average

water temperature and concentration of dissolved oxygen (DO) as warm water holds

less oxygen than cooler water and changing the river's species composition. The

range of tolerance for each critical stage in an organism's lifetime can be quite

different for every species. Cold water species especially fish, are very sensitive to

changes in temperature. For example, at 1 DC a carp (Cyprinus carpio) can survive

in an oxygen concentration as low as 0.5 mg/l, whereas at 35 DC the water must

contain 1.5 mgt!. For the small tolerance range, a slight change in water

temperature can be a problem (Harrison, 1993).

According to Clark and Brownell (1973), many species of fish and invertebrates

initiate spawning activity at least partly in response to higher temperature in the

spring. As a result, organisms attracted to thermal discharges during the winter

may be induced to spawn earlier than usual in the spring. On the other hand, Kaya

(1977) stated that in geothermal heated stream, rainbow trout changed their

spawning period from spring to autumn and thus avoided the hottest period of the

year for hatching and fry development.

In addition, Katz (1971) stated that thermal effects are not restricted to fish. It also

has a marked and measurable effect upon the other organisms including the

aquatic bacteria, the phytoplankton and zooplankton and the macroinvertebrates.

9

.,...

He further explained that changes in the population composition of the flora and

the invertebrates which form the food chain of fish will ultimately adversely affect

the desirable fish population even if the temperature does not approach the lethal

point for the important species of fish. However, estuarine species are expected to

have a greater range of temperature tolerance than sublitoral marine species.

2.3.1.2 Turbidity

Turbidity refers to an optical property of water that causes light to be scattered or

absorbed rather than transmitted through the water in a straight line. The

primarily effect of turbidity is to restrict light and reduce photosynthesis.

Normally, turbidity is caused by various suspended matter such as suspended soil I;

particles, plankton and organic detritus, and soluble coloured organic compounds "

, " in water that interferes with passage of light through water (Boyd and Tucker, "

"1998). Excessive runoff from surrounding watershed can often caused clay and silt :1

loads to exceed 20,000 mgll which is harmfull to fish and invertebrates. However,

Lawson (1995) found out that fish seem to be less affected at concentrations below

20,000 mgll for a short period of time.

Malaysian River water has high turbidity, mostly of silt with 47 % of them having

more that 50 mg/l of suspended solids. Turbidity is measured by unit NTU

(Nephelometric Turbidity Unit. The maximum turbidity level allowed in drinking

water is 5 NTU whereas for raw water, the maximum acceptable level is 1000 NTU

(DOE, 1994).

10

2.3.1.3 Total Suspended Solids (TSS)

Suspended solids consist of suspended soil particles and particulate organic matter

resulting from live plankton and detritus. Suspended solids in water can be

described as the filterable components of the solids present, of which tme particles

are held in suspension for long periods, depending on the intensity of water

turbulence (Avault, 1996). Apart from that, Ali and Murtedza (1999) pointed out

that the measurement of total suspended solids (TSS) can be used to determine soil

erosion rate of that area. The high TSS value indicates that the area experienced

high rates of erosion.

2.3.1.4 Salinity

I

Salinity refers to the total concentration of all ions such as calcium, magnesium,

sodium, potassium, bicarbonate, chloride and sulphate in water. Salinity expressed

in grams per liter (gil) in the SI system of units or parts per thousand (ppt) in the

English System (Lawson, 1995). He further explained that, every species has an

optimum salinity range, and when forced outside of this range, metabolic energy is

spent on osmoregulation at the expense of other functions. Salinity in estuaries

depends on the relative amounts of fresh water and seawater that are mixed

together, varies with both time and location within the estuary, and is influenced by

river inflow, tides, and wind (Boyd and Tucker, 1998).

r I 11

I

2.3.1.5 Conductivity

The unit of conductivity is microsiemens per centimeter (J,tScm-1) or micromho per

centimeter (J.1mholcm). According to Lawson (1995), electrical conductance is a

measure of the dissolved mineral content of the water and changes in direct

proportion to salinity. Conductivity levels in the water indicates the amount of

dissolved matter in the water body. It reflects the condition and chemical and

physical characteristics of the erosion and transportation processes. The higher

value for conductivity shows greater proportion of ions in the water. He further

mentioned that, electrical conductance can be used to obtain reliable estimates of

salinity or total dissolved solids. However, the presence of some unrelated organic

molecules in aqueous solution also contribute to electricity (APHA, 1998). Boyd

(1990) stated that distilled water has a conductivity of about 1 J.1Scm-1 while natural

freshwater ranging from 20·1,500 J.1Scm-1•

2.3.2 Chemical Variables

2.3.2.1 Dissolved oxygen (DO)

Allan (1995) stated that dissolved oxygen in unpolluted flowing nver IS

usually near saturation and as such the concentration of oxygen is of little

biological significance. He further explained that the solubility of oxygen

gases in water is not only affected by temperature and partial pressure but

also by turbulence. It is within these turbulent flows of the stream that

12