The government on Friday announced a $500 million project to dredge and clean up Rio's picturesque Guanabara Bay, polluted by years of chemical waste-dumping.

The federal project, to begin next month, includes the construction of underground drains, recycling plants and waste treatment facilities, said Eliana Farias, a spokesman in the Social Action Ministry.Scientists say it will take until the year 2005 to finish the cleanup.