As the cleanup of the decade-old mercury pollution in Nura river started in Kazakhstan, environmentalists emphasised the need for extreme caution. Mercury had been discharged in the river over many years by a Karbid acetaldehyde plant in Temirtau town, until it closed down in 1997. It contaminated a large area of the riverbed and the floodplain.

According to the government's committee on water resources that was handling the Nura River Cleanup Project, the mercury pollution presented a greater risk to the 1.5 million people living in the affected area than the actual operation of removing it. "When the project documentation was drawn up, any possible risk was reduced to a minimum. But the current situation presents a risk to the public,' said Yevgeniy Lukinykh, chief project coordinator of the project.

Environmentalists are also concerned of the cleanup's possible effect on the biodiversity in the nearby Korgalzhyn national park, where the river flows into dozens of lakes that are home to pink flamingos; an estimated 30,000 of them migrate there. Some 300 species of birds have been recorded at the lake. Concern was also raised regarding the financial aspects of the project.