For years, the seven beaches along the Rambler Channel west of Tsuen Wan have embodied a contradiction: stunning views but filthy water. Pollution was so bad in the 1990s that the government withdrew lifeguards and put up banners warning people not to enter the water. Now, more than a decade after the beaches were closed, new sewage and water treatment facilities have improved the water quality to such an extent that the government has deemed it clean enough for swimming. Lifeguards will return to four of the beaches next summer and the rest will be reopened by 2013, when changing rooms and other facilities are built. Water quality at Anglers', Approach, Casam, Gemini, Hoi Mei Wan, Lido and Ting Kau beaches has improved by 70 per cent since 2005, according to figures released earlier this month by the Environmental Protection Department (EPD). That improvement comes thanks to a new water treatment plant in Sham Tseng and the opening last year of a sewage system in the villages along Castle Peak Road, which had previously relied on leaky septic tanks. So far, 210 of the area's 400 village houses have been connected. 'These seven beaches have been subjected to different sources of pollution from every direction since the 1990s,' said Elvis Au Wai-kwong, the EPD's assistant director of water policy. Raw sewage flowed directly into the sea from restaurants and houses, a problem that intensified as the population near the beaches increased from 26,000 in 1996 to 37,000 today. The improvement in water quality has been dramatic. In 1997, more than 1,500 Escherichia coli (E coli) bacteria were found in 100 millilitres of water gathered at Ting Kau Beach. Today, the count has dropped to 141. Lido and Hoi Mei Wan beaches are even cleaner, with E coli counts of 87. Water at a beach must have an E coli count lower than 180 for the EPD consider it suitable for swimmers. Hong Kong's most popular beach, Repulse Bay, has an E coli count of 11, and the city's cleanest beach, Hap Mun Bay in Sai Kung, has an E coli level of 3 - a reminder that, despite recent improvements, the Rambler Channel beaches remain the most polluted in Hong Kong. The problem is that, even though most local sources of pollution have been eliminated, the harbour's currents take dirty water from other parts of the city and send it towards the Rambler Channel, according to Dr Paul Shin Kam-shing, a marine pollution expert at City University. For that reason, pollution levels will remain steady at the Rambler Channel beaches until levels are reduced in Victoria Harbour. That won't happen until 2014, when the last outflow of raw sewage from Hong Kong Island - about 450,000 cubic metres a day - is finally treated. That hasn't stopped swimmers from taking a plunge at the closed beaches, which already attract several hundred people on summer weekends. One 61-year-old swimmer has visited Lido Beach every day for two years. 'I live in Tuen Mun but I don't like the beaches there - they're too dirty,' he said. 'I can see for myself that the water here is good. Besides, the scenery is great and there's never too many people.'