A boat tour through northwestern Beijing will begin a trial run in July that will herald a major effort by the city to clean up its watercourses. The 20km trip will take tourists from Yuyuanpiao to the lake behind the Beijing Exhibition Centre, cutting through the Summer Palace and Kunming Lake. Even the six boats, which seat between 30 and 50 passengers, are environmentally friendly. Their engines all use low-emission, liquefied petroleum gas. For many years, residents have used the capital's waterways as a rubbish dump. More than 1,600 baskets were found in the watercourses during the Beijing River and Lake Management Bureau's spring clean this year. In 1997, 12,506 baskets were pulled from city waters. Each day, three-quarters of the 2.5 million tonnes of waste water generated in the city is released into canals without processing. There are more than 1,000 sewage openings along the 366km of waterways. The municipal government has decided to tackle the dirty water problem by investing one billion yuan (HK$930 million) to clean up the city's waterways. Top priority is the dredging of major waterways and lakes, while waste water will be diverted into new sewage pipes and processing plants.