WATER QUALITY IN THREE RESERVOIRS
ON THE CITARUM RIVER, INDONESIA
Simon Sembiring *
*Reseacher, Research Institute for Water Resources Development
Jl. Ir. H. Juanda No. 193 Bandung – 40135, Indonesia
Fax : + 62-22-2500163
ABSTRACT
Three large reservoirs have been built on the Citarum River in West Java over the last two
decades. Saguling (completed 1985), Cirata (1988) and Jatiluhur (1967) are the first, second
and third reservoirs respectively downstream from Bandung city. Saguling and Cirata were
built primarily for hydroelectric power and Jatiluhur primarily for rice irrigation.
Subsequently all three are used for industrial, domestic, fisheries, recreation and
transportation purposes. Jakarta city, about 130km from Jatiluhur, plans to use the water from
this reservoir as its main water supply.
It has been known for more than a decade that the water of all three reservoirs is polluted by
inflows of domestic sewage, industrial and agricultural wastes. In addition, considerable
organic pollution comes from fish farming in the reservoirs. In year 1998 Saguling had 2500
floating cage nets, Cirata 2700, Jatiluhur 720 .
A number of pollutants exceed the limits of the official water quality regulation standards of
the government of Indonesia, particularly dissolved oxygen, zinc and iron.
This paper give some updated information about the level of pollution. Unless the sources of
pollution are controlled the effects of it presently seen in macrophyte plant infestation, algal
blooms, fish kills and degradation of potable and industrial water will increase.
KEYWORDS: Citarum , reservoir ,Cirata, Jatiluhur,Saguling, pollution, water quality.
INTRODUCTION
The Citarum is one of the main rivers in Indonesia, with a length of about 315km. Three
reservoirs have been built in the middle basin between Bandung city and Curug where much
of the water flows into an irrigation network. Saguling filled in 1985, Cirata in 1988 and
Jatiluhur in 1967. Their original purposes were for rice irrigation for Jatiluhur, and
hydroelectricity for the other two. The total power generated is 1350 MW for both industry
and domestic use. Subsequently many other functions for the water have developed. Some
general features of the reservoirs are in Table 1.
The river has a typical discharge of about 50 m3/sec in the dry season and about 280 m3/sec in
the wet season, with an annual mean of about 150 m3/sec.
Table 1 : Some features of the Citarum reservoirs
Year filled
Altitude (m)
Area ( Ha)
Catchment area (Ha)
Volume (x 106m3)
Maximum depth (m)
Mean depth (m)
Water level fluctuation (m)
Hydroelectric power (MW)
Original function
Jatiluhur
Cirata
Saguling
1967
115
8300
659.000
2970
90
35.8
25
150
Irrigation
1988
221
6200
603.200
2165
106
34.9
20
500
Hydroelectric
Power
1985
645
5340
334.300
982
90
18.4
20
700
Hydroelectric
Power
SOURCES OF POLLUTION
The major source area of pollution is the upper Citarum basin, which includes the most
important polluting area of Bandung city. The major pollutants are domestic sewage,
industrial waste, arable agricultural runoff including pesticides, and animal husbandry. In the
reservoirs themselves the pollution is the waste from fish farming.
Domestic sewage.
This type of pollutant involves organic material and so produces excessive consumption of
oxygen (as Biological Oxygen Demand, BOD) and excess of the plant nutrients nitrogen and
phosphorus that produce algal blooms and macrophyte plant infestations.
The population in the upper Citarum River basin (Kabupaten Bandung including Bandung
city) is about 6 million people, and in the Citarum catchment as a whole is about 11.4 million.
Of this total population, about 64% discharge sewage directly into the river. 32% have septic
tanks, and about 4% are said to be linked to the municipal treatment system in Bandung.
Direct river disposal alone contributes about 173 tons of BOD per day. Depending on the
efficiency of the septic tanks this figure could be up to double the amount (Table 2). For
typical sewage this is theoretically equivalent to about 25-50 tons of nitrogen and 5-10 tons of
phosphorus per day. Other references give 33.4 tons N/day of nitrogen and 4.4 tons P/day of
phosphorus.
Table 2: BOD loads for the Citarum catchment
Population
Municipal
Septic tank
Direct
BOD load
kg/day
BOD load Direct
kg/day
11,352,481
460,000
3,657,553
7,234,928
256,724
172,513
Industrial waste
Most of the industries in the Citarum are based on organic raw materials and so BOD,
nitrogen and phosphorus are significant. However, the manufacturing industries are also the
most important sources of other contaminants such as heavy metals (zinc, mercury, selenium),
phenol and cyanide.
There are more than 2,500 factories of various industries in the Citarum basin and about 384
are in the upper part. Most are small but their combined pollution load is considerable. The
textile and paper industries are the most important polluters, and next in order of importance
are the rayon, pharmaceutical, food processing and tanning industries. The total BOD load is
about 8 tons/day and the theoretical total nitrogen is about 1 ton/day. Table 3 gives a list of
the major BOD industrial inputs for only the largest factories but which produce by far the
most pollutants.
Table 3: BOD load for each type of major industry in the Citarum basin kg/day
Textile
3270
Paper
1841
Rayon
952
Chemicals
736
Communal sewage system 605
Food and beverage
136
Sugar
130
Tanning
82
Paper products
68
Textile chemicals
63
Basic chemicals
44
Printing
15
Mixed industrial estates
13
Single product food
10
Metal working
10
Fertilizer
8.7
Ceramics
5.8
Animal holding areas
5.3
Electroplating
5
Refrigeration
1.6
Pharmaceutical
0.6
Paint
0.14
Carpets
0.1
Arable agriculture waste
This is most important for the excessive inflow of the plant nutrients nitrogen and phosphorus.
At 1993, the agricultural area in the upper Citarum was 27,976 ha. The annual crop sequence
is mainly rice- cash crop –rice. In general the use of fertilizer (urea and TSP) is relative high.
Urea application is about 200 kg/ha and TSP 100 kg/ha. According to Iskandar (1993), the
pollution load from arable agricultural is approximately 2,800 kg/day for nitrogen and 600
kg/day for phosphate.
Fish farming
The effects of the type of pollutant are similar to domestic sewage.
In 1985 there were about 200 floating net cages in Saguling reservoir. By 1999 this number
had increased to 1,900. In 1999 about 1,700 nets were in Cirata and 520 in Jatiluhuluhur
(Sembiring,1992) .Based on the amount fish feed needed for each net, the total amount of
feed applied is presently about 35,400 tons 12,000 tons and 4,160 tons/year respectively for
Saguling, Cirata, Jatiluhur. Approximately 10 percent of the total amount of fish feed is
wasted and falls to the reservoir bottomKrismono et al, ,1992). Generally fish feed contains
24-26 percent nitrogen, and phosphor 0,96 percent by weight. So that the nitrogen input from
wasted fish feed alone can be estimated as 880 kg/day, 300 kg/day and 104 kg/day for
Saguling, Cirata, Jatiluhur reservoirs respectively. The corresponding phosphorus input would
be 35 kg/day, 12 kg/day and 4.2 kg/day.
The total amount of nitrogen and phosphorus from the fish farming would be much more than
this however because it does not consider excretion from the fish themselves. Digestion for
this type of basically herbivorous animal is only about 50-60% efficient, so that the inputs
mentioned above could be up to 50% greater for the complete farming operation.
Livestock waste
Waste from livestock husbandry can become an important source of pollution. It is equivalent
to domestic sewage in its effect. One cow is equivalent to 5 people. According to Iskandar
,1993) pollution loading to water from animal waste is about 3.3 tons N/day and 0.8 P/day.
Total Nutrient Load
Estimation of pollution loads to from the main sources entering the Saguling, Cirata and
Jatiluhur reservoirs every day is summarized in Table 4.
Table 4: Estimation total loads of nitrogen and phosphorus (kg/day)
WASTE
SOURCE
SAGULING
Nitrogen
Domestic
Industry
Agriculture
Livestock
Fishery
33,350
21.9
2,800
3,281
605
Phosphorus
4,370
600
812.4
24
CIRATA
Nitroge
n
5,800
300
Phosphorus
760
12
JATILUHUR
Nitroge
n
1,450
782
104
Phosphorus
190
167
4.2
-). No. data and very little impact
It is very evident that by far the most important input of pollution is domestic sewage. All the
other categories combined only amount to 20% of the total nitrogen and about 30% for
phosphorus. It is also evident that the industrial inputs are the smallest of the categories. This
would be so even allowing for the obvious errors and gaps in the data. Domestic sewage
disposal is thus shown to be the first priority for pollution management policy, rather than
industrial effluent management.
EVALUATION OF WATER QUALITY
Evaluation of water quality uses here the water quality standards (PP. No. 20/1990) of the
Government Indonesia for: Raw Water Supply (Group B), Fisheries (Group C), Agriculture
and Hydroelectric power (Group D).
Generally the water quality improves downstream in each reservoir. This is because they
function in a similar way as sedimentation ponds for sewage treatment systems. The majority
of particulate material sinks to the bottom of the reservoirs. However, over time the lower
reservoirs will develop worse water quality.
The condition of both Saguling and Cirata is poor because their waters are completely
deoxygenated below 5m from the surface. Jatiluhur remains oxygenated to the bottom at
present, so the other two reservoirs should also be oxygenated to the bottom if there was no
organic pollution. This deoxygenation is the main cause of the frequent mass fish deaths in
the fishing industry. Deoxygenated deep water is also passed thought the hydroelectric
turbines which in the long term will damage them. The following evaluations are for the
surface waters only. No deep water is normally sampled.
Saguling reservoir
In general the water quality of Saguling reservoir for Raw Water Supply category is adequate,
but water quality at the sampling stations at Batujaya, Cilawu and Cimerang is very bad,
particularly for dissolved oxygen, oil and grease, iron, mercury, selenium, cyanide, phenol,
hydrogen sulphide, all of which exceed the concentration limits for this category.
Water quality for the Fisheries category at all sampling stations is very bad. Hydrogen
sulphide, ammonia, nitrate, zinc, mercury, selenium, chlorite, phenol and dissolved oxygen all
fail the regulation standards.
Water quality for the category Agriculture and Hydroelectric power is adequate, with the
exception of selenium which exceeds the standard at all locations. However, the high
hydrogen sulphide concentration will be damaging to turbine metals given time.
Cirata reservoir
Water quality of Cirata reservoir for all the categories of Raw Water Supply, Fisheries,
Agriculture and Hydroelectric power is better than that of Saguling. This is because of the
sedimentation effect mentioned above, but also because only about two thirds of Cirata water
comes from the Citarum river, the remainder comes from the Cisokan, Cikundul and other
rivers. These rivers are not as polluted as the Citarum and so dilute the pollutants from
Saguling. This dilution only delays the time when the water of Cirata will become as bad as
that of Saguling now. Cirata does have an important direct pollutant source from the fish
farming. Dissolved oxygen, zinc and hydrogen sulphide exceed the regulation standards for
Raw Water Supply and Fisheries. Water quality for Agriculture and Hydroelectricity is very
good for all parameters.
Jatiluhur reservoir
Although the water of Jatiluhur is polluted, presently the quality of the water is still good.
According to data from 1992 and 1995 all the water quality parameters are within the limits
for Raw Water Supply, Fisheries, Agriculture and Hydroelectricity. However, as pollution
continues to flow into the reservoir from various sources including the water from upstream it
is only a matter of time before the water of this reservoir begins to deteriorate in the same way
as the two reservoirs upstream have deteriorated.
CONCLUSIONS
-
Saguling reservoir is polluted by domestic sewage, manufacturing industries mainly from
Bandung city. There are considerable diffuse inputs of sewage from human populations
and agriculture. Fish farming is a direct source.
-
The Cirata and Jatiluhur reservoirs are polluted directly by fish farming and from the
long-term effects of inputs from Saguling and from various sources in the surrounding
catchment, particularly from diffuse domestic sewage.
-
There is a gradation of increasing water quality from Saguling to Jatiluhur because of the
sedimentation and recycling effects of the reservoirs.
-
Present water quality of Saguling is adequate for Raw Water Supply and Fisheries good
for Hydroelectricity.
-
Present water quality of Cirata and Jatiluhur is good for Raw Water Supply and Fisheries
good for Hydroelectricity.
-
In Saguling reservoir dissolved oxygen, hydrogen sulphide, zinc and iron exceed the official
limits for fishery and raw water supply , .
-
In Cirata reservoir dissolved oxygen, hydrogen sulphide, zinc and iron exceed the official
limits for fisheries.
-
The water pollution conditions in the whole of the catchment of the Citarum area are poor,
particularly in the upper catchment which includes the city of Bandung. This part of the
catchment especially affects the Saguling reservoir which is badly polluted.
-
The Citarum basin needs to be managed against further water pollution, especially in the
upper catchment. By far the most important source of pollution to control is the domestic
sewage. But significant toxic heavy metals, phenol and cyanide comes from industrial
sources for which law enforcement needs to be strengthened.
REFERENCES
Anonymous, 1999; Water quality Report of Saguling Reservoir, Institute of Ecology,
Padjadjaran University, Bandung , co-operation with Perusahaan Listrik Negara (PLN).
Krismono, et al 1992, Impact of Fish Farming in Floating Net for Water Quality at Reservoir
Saguling, Proceeding at Research Institute for Fishery, Ministry of Agriculture.
Iskandar Yusuf, 1993, Waste Load Allocation for Long Term Water Quality Management at
the Upper Citarum River Indonesia, Thesis Master of Science University of Manitoba,
Canada.
Simon Sembiring, 1992, The Water Quality Impact on Fishery in the Saguling Reservoir
Indonesia. In Proceedings of the Sixth International Symposium River and Lake,
Conservation of Lake Ecosystem and Management on Watershed, Environmental
Research Institute Kongweon National University, South Korea, 240-261.
Simon Sembiring. and Firdaus Achmad, 1997, Eutrophication in three reservoirs in the Citarum River
basin and its relationship to beneficial uses, In Proceeding Workshop at the Management of
Lake, Kuta, Bali; Indonesia , Juli 1997, 199- 214.