At a meeting with Prime Minister Nguyen Xuan Phuc in Hanoi on Thursday, water pollution was among the topics a visiting delegation of Japanese environmental experts discussed.

With a length of about 14 kilometers (8.7 miles), the To Lich runs through the downtown Thanh Xuan, Hoang Mai and Thanh Tri districts. It has been heavily polluted for years and is now infamous for its black water and stench.

Dr Tadashi Yamamura, a U.N. environmental specialist, chairman of Japan's Trade-Environment Promotion Organization and head of the delegation, offered to provide Vietnam bionanotechnology equipment for free to tackle pollution in a section of the river and the capital's largest freshwater body West Lake, which received 4,000 cubic meters of untreated wastewater every day.

The equipment, which includes an aerator that employs nanotechnology to quickly treat water using natural materials, will be installed on the bed of the river.

The Japanese experts said the river's stench would reduce significantly within just three days.

Yamamura said Japanese experts had done investigations and surveys for two years to come up with the proposal.

Phuc hailed the proposal as "a good idea, very practical for Vietnam" and appreciated the Japanese side for mobilizing funds for the project from private sources.

He told the visitors to work with the Ministry of Natural Resources and Environment and the Hanoi government to decide on a plan to clean up the To Lich.

The PM expressed trust that the new technology would be successful in treating wastewater and the polluted water sources in Hanoi as well as elsewhere in the country.

In October 2016, Hanoi started work on a $726 million sewage treatment plant which is expected to finish in three years and be capable of treating 270,000 cubic meters of sewage collected from the Lu, To Lich and Nhue rivers every day.