The Hanoi Committee has announced that the second phase of a mass clean up of the city's lakes will start later this month.

"Most of the lakes have varying levels of pollution," said Ngo Thai Nam, deputy director of the Hanoi Environment Protection Department (EPD).

Waste water and algae are just two of the problems currently affecting the nine lakes that have been earmarked for treatment in the phase including Giang Vo, Van Chuong, Thien Quang, Nghia Tan, Van Quan, Ho Vo, Den Lu, Giap Bat and Ao Lam Du.

Pollution has become a big problem for people living by the lakes. In March this year, local citizens were subjected to the smell of rotting dead fish in Truc Bach.

An investigation by the EPD showed that the fish died due to seriously polluted water and tens of other lakes were affected by the same problem.

To date, 65 lakes in Hanoi remain to be dredged and cleaned, but there are no plans for operations at 33 others, including Thuy Su, Kim Lien and Me Tri.

The project started in September 2009 with a total investment of VND2.6 trillion (136.8 million USD). It is planned to finish in September this year. In the first phase, 46 lakes were treated and the quality of water improved.

"Water quality is getting better but sometimes it is only a temporary fix. In some cases, the problems return due to a lack of preservation," said Nguyen Le, general director of the Hanoi Water Drainage Company.

Professor Vu Hoan, chairman of the Union of Science and Technology Associations said that the city had tried a number of treatment techniques but the pollution still returned.

Nguyen Van Luong, director of the of Hanoi EPD, said the best way to solve the problem was to ban the release of all untreated sewage into the city's lakes.

"Comprehensive management of the lakes is needed but this is complicated at the moment as it involves local authorities, co-operatives and individuals," he said.

Educating local people on how to protect the environment was also an important task, Luong added.

There are several waste water treatment facilities, but they do not have the capacity to deal with the city's waste./.