Most rivers face severe pollution, study finds

Adianto P. Simamora, The Jakarta Post, Jakarta  | Tue, 12/02/2008 7:20 AM  

Siti, a housewife who lives near the Kalimalang canal in East Jakarta, is familiar with the sight of dead fish floating up from the murky depths after overnight rains. 

“We often find dying fish and shrimps in Kalimalang river, usually in the morning after the heavy rains. Many residents go into the water to collect the fish,” she says. 

“What we (residents) understand is the fish die because certain companies dump hazardous waste into the river.” 

The recently published Indonesian State of the Environment Report includes the canal, which runs down the middle of Jakarta, as one of the most polluted rivers in the country. 

The 2007 report, issued by the State Ministry for the Environment, revealed that water quality in rivers, basins and small lakes continued to be severely polluted by domestic and industrial waste, despite being the main sources of drinking water. 

The ministry surveyed 33 rivers in 30 provinces, most of them moderately to severely contaminated.

The most polluted rivers are North Sumatra’s Deli, Lampung’s Way Sekampung, Jambi’s Batanghari, Banten’s Kali Angke, Yogyakarta’s Progo, East Java’s Brantas, and the Kalimalang. 

“The survey represents the real conditions of rivers in the country. But the report did not study the sources of pollutants,” Antung Deddy, deputy assistant minister for river and lake management, said Monday. 

The survey focused on 16 parameters, including biochemical oxygen demand (BOD), chemical oxygen dioxide (COD), pH, and fecal coli and coli form. 

In terms of pollutants affecting the BOD — the total oxygen required by microorganisms to decompose organic substances in sewage — water in most of the rivers was no longer suitable as drinking water. 

“The highest BOD concentrations are in Java, with 185 milligrams per liter in Surabaya River and 155 in Citarum River, West Java,” the report said. 

The Public Works Ministry earlier predicted the country would need more than 311 million cubic meters of drinking water in 2012 because of the population boom. 

The densely populated Java Island alone will need about 184 million cubic meters in 2012 and 312 million cubic meters in 2025. 

The report, used as a basis for other departments in making policies related to infrastructure development, also found fecal coli levels that far exceeded government-specified limits. 

Water quality in basins also suffered from high concentrations of BOD pollutants, the study showed.

The study examined 18 basins, including Darma, Selorejo and Sempor on Java Island. 

The government blamed riverbank dwellers as the main source of the pollution. As of 2005, there were 118,891 families, mostly in Jakarta, living along riverbanks. 

In addition to this, about 8 percent of households across the archipelago dump their domestic waste directly into rivers, the survey found.