Acid water, hot mud, and damaged rice

 Duncan Graham   |  
The spectacular view of Kawah Ijen volcano’s crater lake is tempered by the drudgery and danger of sulfur miners’ work and the extraordinary acidity of the waters. Runoff from the lake creates hardships for downstream communities as it contaminates drinking and irrigation water. (Photo: Ciska Tobing)

The spectacular view of Kawah Ijen volcano’s crater lake is tempered by the drudgery and danger of sulfur miners’ work and the extraordinary acidity of the waters. Runoff from the lake creates hardships for downstream communities as it contaminates drinking and irrigation water. (Photo: Ciska Tobing)


Volcanoes are a double edged sword for the rice farmers of East Java. In many areas, volcanic ash helps create rich, fertile soils that allow farmers to plant three crops per year. But just as easily as they can provide, so can volcanoes damage and destroy.

Two volcanic calamities in the Indonesian province of East Java are getting worse, with no speedy solutions in sight. Together, the disasters have dramatically affected the lives of thousands and destroyed large areas of productive land.

It’s not possible to blame human error for the first problem—the continuous leaching of acid water from the Kawah Ijen volcanic lake at the east end of Java. The pollution of downstream rivers and wetlands has been known for many decades but only now has the impact been measured.

The second crisis is more recent, with the repercussions yet to be fully understood. The eruption of subterranean hot mud around an exploration gas rig is alleged to have been caused by flawed drilling procedures.

East Java, just south of the equator, is home to around 38 million people, with about 70% earning their living directly and indirectly from the land. The most important cash crops are rice, sugar, and tobacco, with fruits and vegetables grown on the cooler uplands.

A chain of six volcanic ranges runs east to west, with some peaks regularly belching smoke and ash. Along with the rich volcanic soils, heavy rains between October and May also make East Java a farmer’s paradise.

Paradise becomes lost, however, in the land surrounding one of the volcanoes, Kawah Ijen. The volcano’s crater lake, one of the biggest in the world, holds about 36 million cubic meters of hyper-acidic water saturated with a potent mix of numerous minerals. It’s about 200 meters deep and the water temperature varies between 20 and 40 degrees Celsius. Although regularly replenished by rain, the waters are not diluted. Gasses burping from the bowels of the earth through the water continually create extreme pollution.

About 50 liters of water per second leak from the lake into the Banyupahit-Banyuputih (bitter and white) River. This flows down to Asembagus on the Straits of Madura. There, more than 3,500 hectares of rich land are irrigated from the dammed river. The favored crop is rice—but this is acid-sensitive. Around 70% of plantings fail. Sugar cane is more tolerant but less profitable.

(Photo: Thom Bogaard, University Utrecht, and Ansje Löhr, Open University Netherlands)

(Photo: Thom Bogaard, University Utrecht, and Ansje Löhr, Open University Netherlands)

The water fails all standards for irrigation and drinking. No fish skim the waterways, no reeds whisper in the breeze. This is toxicity on a grand scale. The long-term effects on the 50,000 people who live in the area are not known, but in some districts up to 90% have black teeth. This condition is caused by an excess of fluoride, a compound added in tiny doses to the water supplies of many nations to reduce tooth decay.

Skin and eye problems are also easily visible. But what’s happening to people’s bones and brains? Are any of the minerals retained in the body? More study is needed to determine the other effects.

According to Indonesian government vulcanologist and geochemist Sri Sumarti, the problem was identified almost a century ago.

In 1921, the Dutch built a sluice near the outfall. When the lake was full, the gate was lowered and excess water flushed out to sea after downstream farmers were alerted.

“The crater lake last over fl owed in 1976,” says Dr. Sumarti. “The sluice has been renovated since then and could be used but that solution is no longer appropriate. We don’t know why the lake levels are decreasing but its probably seepage through the porous ground. The level is now 15 to 20 meters below the sluice.”

Vulcanologist Manfren van Bergen from Utrecht University in the Netherlands says the Dutch started watching volcanoes seriously and keeping records of activity after Kelut Volcano erupted in 1919, killing about 5,000 people near Kediri in central East Java. Kelut also had a crater lake, and the fountain of hot mud and rock devastated 15,000 hectares of good land.

“After Independence (in 1945), the Dutch were unwelcome for a while, but the records of volcanic activity were preserved in Holland,” says Dr. van Bergen. “Long-term information is critical in forecasting events.”

Now that international relationships have improved, the old statistics are available and nearly US$800,000 has been allocated to research on Kawah Ijen. Researchers sought solutions at a workshop in the East Java capital of Surabaya in August 2006. The meeting was also attended by affected farmers and government officials, many of whom offered obvious and imaginative proposals to solve the acid-water problem.

A proposed big engineering project never started. It would take at least 55 kilometers of piping to drain the lake and send the water to the sea. The pipes would have to be made of acid-proof materials and would be prohibitively expensive.

(Photo: Greenpeace/Vinai Dithajohn)

(Photo: Greenpeace/Vinai Dithajohn)

Diluting the acid is also impossible. This would take mountains of limestone, and, according to environmental scientist Ansje Lohr from the Netherlands Open University, even then the gasses would continue to percolate.

Dr. Lohr has worked on a survey of 23 villages in the area. This found only a “partial awareness” of the problem, despite the black teeth and the sulfur-yellow water. Surprisingly, many said the water was not distasteful—maybe because it’s the only water the locals have ever known. Even families who bought drinking water or who had an uncontaminated well were still affected by swallowing water while bathing.

“There are many unanswered questions because there’s been little research,” says Dr. Lohr. “Cattle graze the area, so will bakso (a meat ball soup) made from the beef be contaminated? And what about vegetables and cereals grown with the acid water? We don’t know. Most farmers depend on irrigated water. They want to grow rice, but most of it dies. The people are getting really poor.”

The priority, according to soil technologist Budi Widianarko from Soegijapranata Catholic University in Semarang, Central Java, is to get clean drinking water to the villagers.

“We can’t handle the two issues of public health and finding a long-term answer simultaneously,” says Dr. Budi. “Access to safe water is critical. Any new wells must be free from future contamination. Solutions for agriculture are more complicated. The pollution is causing more and more problems, economically, socially, and in people’s physical and mental health.”

Dr. Budi forecast that in the long run government subsidies would have to be paid if people were to stay in the area. These could make up the difference between profit from a rice crop and a cane harvest so farmers would concentrate on producing sugar.

But should the people remain? If the risks to their well-being are acute, the impact on health unknown, and the chances of making a good living remote, then maybe the long-term solution is to relocate the farmers and abandon the land.

Could the water’s minerals be extracted and sold? Utrecht University geoscientist Thom Bogaard thought gypsum could be recovered, but, again, the cost might exceed the value of the mineral.

“More research is required,” says Dr. Bogaard. “This isn’t just important for Kawah Ijen but for all volcanoes in Indonesia. About 10% have acid lakes. People are moving higher and higher to make a living from the land. The danger is that one solution could create another problem. Any answer has to be sustainable.”

But there’s another scenario that’s beyond all the planning and report writing. Kawah Ijen is dormant—not dead. If it explodes again, any attempt by humans to control nature will vanish in a hail of volcanic ash and storms of acid water.

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