Oil Palm Plantations Threaten Water Quality

The clearing of tropical forests to create oil palm plantations is threatening water quality, according to researchers from Stanford University and the University of Minnesota - a hazard to millions who depend on streams for drinking water.

Palm oil, found mostly in products like peanut butter, shampoo and packaged bread, is a booming multi-billion industry, popular in Indonesia. But the oil palm plantations built to manufacture these products are posing environmental problems. Not only are such plantations associated with dangerous and abusive conditions for laborers and the release of massive amount of harmful carbon dioxide into the atmosphere, fueling climate change, but now they are adding contaminated freshwater to the list.

The new study, published in the Journal of Geophysical Research: Biogeosciences, contains surprising findings about the intensity and persistence of the impact on drinking water, food and livelihood, even in areas fully forested with mature oil palm trees.

"Although we previously documented carbon emissions from land use conversion to oil palm, we were stunned by how these oil palm plantations profoundly alter freshwater ecosystems for decades," co-author and team leader Lisa M. Curran, a professor of ecological anthropology at Stanford and a senior fellow at the Stanford Woods Institute for the Environment, said in a statement.

During the process of land clearing, plantation management - which involves fertilizer and pesticide application - and processing of oil palm fruits, sediment, nutrients and other harmful substances can leach into streams that run through plantations. The research team found that sediment concentrations were up to 550 times greater in streams running through plantations than unaffected forest streams.

Indonesia, which produces almost half of the world's palm oil and is home to the world's third-largest tropical forest, is a major hub for this growing environmental problem. About 35 percent of Indonesian Borneo's unprotected lowlands may be cleared for oil palm in coming years, according to previous research by Curran.

It's possible that land changes from this industry will impact fisheries, coastal zones and coral reefs - potentially many miles downstream - but as this is the first study to assess the impact of oil palm plantations, the answer remains to be seen.

"Local communities are deeply concerned about their freshwater sources. Yet the long-term impact of oil palm plantations on freshwater streams has been completely overlooked until now," Curran said. "We hope this work will highlight these issues and bring a voice to rural communities' concerns that directly affect their livelihoods."