This is the second of three stories on the impact of the polluted Citarum River.
While Jakarta is traversed by 13 rivers, none of them a used to supply the capital with raw water. Instead, the government chose a 269-kilometer-long river that runs outside of the capital as the main supplier of raw water.
Citarum River does not pass through Jakarta, but a canal made in 1966 carries water from the river to the capital.
The river stretches around 14 kilometers from Halim junction to Bekasi, and the West Tarum canal, or Kalimalang as it is popularly called, channels the raw water into Jakarta to be processed and distributed as clean water by two tap water operators: Aetra, which serves North and East Jakarta and Palyja, which serves West and South Jakarta.
Both Aetra and Palyja have been affected by the recent dike collapse on the Kalimalang canal. However, of the two companies, only Aetra agreed to speak with The Jakarta Post.
Muhammad Selim, president director of Aetra, said that the quality and quantity of raw water from Citarum River had been decreasing over the past five years. This has forced the water company to reduce its water production, which has affected its customers.
“Despite all of its flaws, Citarum River’s raw water is still the best option we have for raw water. There is no other choice but to use it as best we can,” Selim said.
The raw water redirected from the river, he said, had high turbidity and contained ammonia, manganese and organic materials.
“The ammonia is probably caused by the fish food thrown into the freshwater fisheries at the Jatiluhur Dam. So far, we have yet to find any mercury in the water,” he said.
A 1995 Jakarta gubernatorial decree stipulates that the maximum turbidity of raw water used to produce tap water is 100 nephelometric turbidity units (NTU), but the Buaran water processing was designed to handle a maximum raw water turbidity of 1,750 NTU.
When the Buaran installation was designed in 1987, the turbidity level of the raw water supply was between 600 and 1,000 NTU.
Since then the turbidity level has been increasing, with a level of 28,000 NTU recorded in February 2010, or 28 times higher than 20 years ago.
“High turbidity is usually recorded in the rainy season, perhaps due to deforestation in upstream areas, which causes erosion,” Selim said.
As for supply volume, there have been several sudden stoppages of water flow at the Jatiluhur dam.
The stoppages occur because the dam management office also uses Citarum River to irrigate paddy fields in the area.
During times of irrigation, the dam channels less water to Jakarta, which means the capital must use raw water from the Cikarang, Cibeet and Bekasi rivers.
However, it takes two-and-a-half days for water from these alternative rivers to reach Jakarta. Thus, if the Jatiluhur dam office is late notifying Jakarta’s water companies, supply to Jakarta residents can be disrupted.
The Jakarta administration has planned to build a pipeline connecting Jatiluhur Dam in Purwakarta, West Java, to a water treatment facility in Buaran to increase the reliability of water supply for Jakartans.
The project has been estimated to cost Rp 3 trillion (US$351 million), and would be financed by the Public Works Ministry.
However, the project will not begin until next year, meaning Jakarta will continue to rely on the Citarum River for raw water supply for some time.
The collapse last week of the Buaran dike left 570,000 Jakartans without clean water supply.
Aetra recorded that in the first half of the year, 60.3 percent of all of the problems it faced were raw water supply-related problems.
“We want to create an early warning system with the Jatiluhur Dam management office so that we can minimize disruption,” Selim said.
The company also launched a green movement in Sunten Jaya, a village located in the upstream area, to reduce sedimentation in the river.
Farmers in the village have agreed to change from a monoculture plantation technique for vegetables farming to an intercropping system, which involves wooden trees, which absorb more rain water.
To improve raw water quality, the government is building an underground tunnel to channel water from Citarum River below Bekasi River so that the waters from the two rivers do not mix.
A. Hasanuddin, head of the Balai Besar Citarum river development office, said that the construction of the tunnel had started this year, and would be complete before the end of the year.
“Our target is to bring Citarum’s raw water quality to Class 2,” he said.
In the absence of reliable tap water supply, some Jakartans have built groundwater wells in their homes.
Nova, a resident of East Jakarta, said that her family built a well connected to an electric pump because they could not get reliable tap water supply.
“We only use the well if there is a service disruption, which happens quite often, actually,” she said.
Although some groundwater is clean, pumping it out can cause land subsidence.
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