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