Many Asian countries are facing huge costs to clean environmental damage done to surface and ground water due to a lack of investment in sanitation, a senior official at the Asian Development Bank said Tuesday ahead of a global conference on the issue.

“Failure to act on sanitation and wastewater eventually comes home to roost when the problem results in a smelly, foul, turgid river that despoils a city and surrounding areas,” said Amy Leung, ADB Principal Urban Development Specialist. “But the real horror is the outbreak of typhoid and cholera caused by inadequate sanitation.”

One notorious example is Shanghai's Suzhou Creek, which runs through the metropolis. For decades, the river had been used as sewer by the city. In the 1970s and 80s, the river became black and emitted a pervasive stench.

In an effort to bring the creek bank from the brink, Chinese authorities will have spent over $1 billion over a decade by 2008, according to ADB. While it has improved, it still needs additional work before the water is considered clean.

Officials acknowledged that the cleanup costs were much more than the cost of preventing pollution, the agency added.

The cost of cleaning a river once polluted with industrial waste or sewage is far higher than the cost of building the infrastructure needed to dispose pollutants properly, the bank said.

China announced last year that it will spend $125 billion over five years to improve water security and build sewage treatment systems in urban areas.

About two billion Asians - roughly 66 percent of the population in Asia - lack access to adequate sanitation, such as toilets, pit latrines, septic tanks, and sewerage system, the bank said. This accounts for nearly three-quarters of all those in the world without such facilities.

ADB will meet to discuss sanitation and other water issues at World Water Week in Stockholm from August 12 to 18.