Untreated filthy surface runoff was (as of 2008) the main source of pollution; in the 1980s it contributed one to eight times more petrochemical waste than direct industrial waste. As of 2008, nearly 80% of the surface runoff in the Central Administrative District is still flushed into the Moskva and Yauza untreated. Until 2000 the river was used in winter as a dump for snow collected from the streets, adding chlorides, soot, rubbish and more oil into the mix. This practice is now banned; the city now employs a network of snow-melting dumps that feed polluted water into treatment facilities.