Jakarta in dire need of better sewage system

Urip Hudiono, Jakarta

This is the first of a series of three articles on the environmental problems caused by untreated sewage in the capital, and the inevitable river and marine pollution it causes.

Jakartans were startled to see untold thousands of fish washed up dead on the beaches of Jakarta Bay in May, but quickly accepted the explanations of officials that it was a natural phenomenon.

It nevertheless raised concerns about pollution in the bay's waters, as further investigations indicated that the oxygen- depleting algae proliferation was spurred by a high level of nutrients in the water originating from inorganic and organic waste.

While the inorganic waste is mostly untreated industrial waste, the organic waste is basically raw sewage discharged into rivers which finally ends up in the bay.

Indications that untreated sewage has been finding its way into the city's rivers are nothing new, as the Jakarta Environmental Management Agency (BPLHD) has repeatedly reported its discovery of E-coli bacteria in all of the 13 city rivers it regularly monitors.

The bacteria, which come from human feces and can cause diarrhea, have also been found to have contaminated up to 80 percent of shallow artesian wells in the city.

These findings have led to questions about just how well Jakarta manages its sewage.

Data from the BPLHD shows that Jakarta's population of some 12 million people produce no less than 1.5 billion liters of sewage each day -- far above the total 600,000 liters that can be handled by the Pulo Gebang, East Jakarta, and Duri Kosambi, West Jakarta, sewage treatment plants.

Jakarta also has a US$6 billion sewage treatment plant in Setiabudi, South Jakarta, which utilizes a network of underground pipes to collect waste water from surrounding houses and buildings. This large-scale treatment plant can process up to 500 liters per second, or over 40 million liters per day.

In the absence of adequate treatment facilities, city residents have to rely on private septic tank installations, but many of them are inadequately designed, according to the BPLHD.

The agency revealed that only 39 percent of the septic tanks can properly neutralize untreated sewage. The rest, meanwhile, can barely process human waste, let alone handle other types of waste water, such as bathing and washing water, which is simply discharged into the city's drainage system to end up in its rivers.

Other residents simply pipe their raw sewage out into rivers despite the existence of regulations against this.

The city's 36 large-sized 6,000-liter capacity sewage trucks and private sector's 83 smaller 2,000-liter capacity trucks empty the septic tanks. A septic tank normally needs to be drained once or twice a year.

However, many truck drivers prefer to discharge the sewage into the city's rivers instead of transporting it to the treatment plants.

Amir Sagala, a waste management official with the Jakarta Sanitation Agency, said that it was impossible to rearrange the already chaotic sewage treatment system, pointing out that converting the city's existing system of septic tanks into one based on sewage pipes would be a difficult and costly task.

"This city's infrastructure is, unfortunately, only being developed now, after the city has been built," he said. "However, I'm sure that in particular business districts with high-rise buildings, or newly developed residential areas, it would still be possible to adopt and implement such a piped sewage system," he said recently.

Meanwhile, Pudjo Prihadi Santoso, director of city-owned sewerage company PAL Jaya, which operates the Setiabudi sewage treatment system, said that the construction of an integrated sewage treatment system for the whole city would be extremely expensive.

Pudjo explained that a piped sewage system like the one in Setiabudi would only be economically feasible if 40 percent of its costs were allocated to construction, maintenance and the operation of the treatment plant alone.

"If the ratio is anything less than that, then the project will be more concerned with installing pipes than with treating the sewage itself," he said. "The city's level topography, meanwhile, would also mean additional investment for pumps to ensure that the sewage flowed properly into the treatment plant's aeration pond."