The Asian Development Bank announced it would provide equity and loans of up to $146.6 million to improve the water supply and wastewater treatment for China's polluted Songhua River Basin.

The basin, China's third largest and one of the country's most polluted, is home to 62 million people.

The Songhua, like many of China's rivers, has faced widespread contamination from the discharge of untreated wastewater. Increasing migration from China's rural areas to urban areas is further straining public services in cities and towns.

In one of China's worst cases of river pollution, 100 tons of benzene and nitrobenzene compounds were released into the Songhua River after a November 2005 explosion in a petrochemical facility owned by the China National Petroleum Corp. in Jilin City, creating a 50-mile-long toxic slick that eventually reached the Amur River in Russia.

The Chinese northeastern city of Harbin was forced to cut water supplies to 3.8 million people for five days following the accident.

The ADB project for building, rehabilitating and privatizing the Songhua River Basin's water supply and treatment plants, is to be carried out by Tongfang Harbin Water Engineering.

The company has earmarked capital spending of $512.6 million from 2009-11, partly financed by ADB, to treat an additional 2 million tons of wastewater a day. Private investors and local commercial banks are expected to provide the rest of the funding.

"Treating more wastewater and improving the supply of potable water will reduce pollution in the urban environment around the Songhua River Basin and improve the health and quality of life for millions of residents," said Philip Erquiaga, director general of ADB's Private Sector Operations Department, in a release.

Since 2005, ADB has supported the Songhua River Basin Water Pollution Prevention and Control Master Plan with technical assistance and loans totaling around $400 million.

In 2008, ADB extended a loan of $200 million for the Songhua River Basin Water Pollution Control and Management Project, covering more than half the total estimated project cost of $396.3 million.

That project was for building infrastructure and providing training to improve and expand water supply, wastewater treatment and solid waste management. It also addressed water shortages by recycling wastewater and focusing on reducing wastage.

ADB, established in 1966, is dedicated to reducing poverty in Asia and the Pacific through inclusive economic growth, environmentally sustainable growth and regional integration, states its Web site.