T

he Jakarta administration is looking into the use of decomposer bacteria to treat polluted water in the city water bodies to see whether it can be an alternative way to provide potable water for the city.

Deputy Governor Basuki “Ahok” Tjahaja Purnama said Saturday that the administration would hold a
trial in a Ciliwung River tributary near the State Palace beginning this year.

“I have invited a Chinese company that had done similar work in China. If it succeeds, it can provide an alternative for clean water provision,” Ahok told reporters at City Hall.

The deputy governor said that the company had also presented their bacterial technology to the central government.

“According to them, the bacteria decompose waste in the water and is safe for humans. So, I think we need to hold trial first,” Ahok said.

City sanitation agency chief Eko Bharuna said that the bacteria can be used to decompose waste sediment in the tributary.

“It would take three months for the bacteria to turn the black murky water clear and odorless,” Eko said.

The agency chief said that the bacteria for the trial was free. “If it can actually work, there’s a chance to use this bacteria in all rivers in Jakarta,” he said.

Eko said that the Chinese company has requested that the bacteria and their company name be kept secret until there was formal agreement with the city administration.

The administration has been working to produce more potable water for its residents. The city is planning to construct water treatment plants that are designed to use ultrafiltration processes to produce potable water.

Ultrafiltration produces clean water by passing dirty water through semipermeable membranes using hydrostatic pressure.

Five plants will be built near five main waterways in the capital — the Pejompongan River, the West Flood Canal, the Cengkareng drain, the Krukut River and the Pesanggrahan River.

The plants that were supposed to have gone into operation before the end of last year, but had to be postponed due to delayed approvals for the city to extract water from its rivers from the Public Works Ministry’s water management directorate.

The new water plants, when operational, are expected to produce a total of 4,500 liters per second. In its initial plan, the clean water will be sold to the city tap water distributors PT PAM Lyonnaise Jaya and PT Aetra Air Jakarta at Rp 2,000 (20 US cents) per liter.

The city’s existing plants produce 8,000 liters of clean water per second, far below the ideal rate of more than 26,000 liters.

The tap water operators currently provide clean water to only 60 percent of Jakarta’s residents. Forty percent of the population relies on groundwater because of the limited coverage of the pipeline network.

Extensive groundwater extraction by residents, in addition to pressure from high-rise buildings, has increased the land subsidence rate in the city in past years.