Around 150,000 cubic meters of untreated wastewater is dumped directly into the To Lich River daily, driving its water quality metrics to abysmal levels.

Back in 1980, Vu Trong Hong, then the deputy headmaster of Hanoi's Thuy Loi University, used to take his students to the To Lich River to clean it up.

Along its banks were villages and fields where farmers grew rice and vegetables. Hanoi's population was around 2.5 million people then.

39 years later, the capital's population has changed beyond Hong's recognition. Its water has turned blackish and miasmic. It currently receives 150,000 cubic meters of wastewater from 1 million people daily, with 280 sewer outlets placed along a 14 kilometer length. And all this is merely a sixth of all the wastewater discharged in the city every day.

Only 22 percent of Hanoi's wastewater is treated, meaning the rest is dumped directly into the rivers and lakes of the capital, according to statistics from the Hanoi Sewage and Drainage Company. This carries organic residues, chemicals, heavy metals and microorganisms, polluting the water environment and affecting water companies downstream, driving water quality test levels way below the national standards.

Hong, saddened by the transformation of the beautiful river, is also worried about its impacts. Pollutants in untreated wastewater is absorbed into the soil and contaminates underground water sources, he said. They would then be consumed by the population through the food they eat, he added.

"When the pollutants start to cause malignant diseases, the problem is no longer simply the stench and the insanitation," he said.

Misplaced priorities

The fact that Hanoi's drainage system doesn't differentiate between wastewater and rainwater isn't new. In the late 20th century, when Vietnam started to open itself to the world, people cared more about the food they bring on the table or the clothes they wear than things like wastewater treatment, said Hoang Van Nghien, former chairman of the Hanoi People's Committee.

In 1998, the capital launched a $550 million drainage project aimed to stop downtown flooding. While the sewer systems were upgraded, nothing was done about separating rainwater from wastewater in its pipes.

"How do we even get the money to do that? An underground sewer in the city is not a simple task," Nghien said. The "easier" option is to turn all four major rivers in the city (To Lich, Kim Nguu, Lu and Set) into sewers.

Nghien now realizes that Hanoi had far behind, many years behind, in wastewater treatment.

"We can't let this continue forever for people to suffer."

"The fact that wastewater and rainwater aren't differentiated into separate systems has many consequences," said Bui Ngoc Uyen, staff of the Hanoi Sewage and Drainage Company.

A water quality survey of 30 lakes in Hanoi by the Center for Environment and Community Research in 2015 showed 25 were heavily polluted. Many of them had around three to six sewers dumping wastewater directly into them.

As for the To Lich River, numerous water quality tests from 2014 to 2018 has shown it to be extremely polluted.

Trash downstream the To Lich River in Hanoi. Photo by VnExpress/Ngoc Thanh.

Inaction in action

In 2009, Hanoi People's Council resolved to address three of the most pressing environmental concerns in the city: solid waste collection, water treatment and air pollution. Wastewater would be sorted and treated before dumping it into the environment back then. More than 10 years later, no such project has been completed.

The city did begin construction of the Yen Xa wastewater treatment plant in Thanh Tri District in 2016, with the hope of collecting and treating wastewater from seven districts in the capital. The VND16.2 trillion ($697.4 million) project was to be completed this year, but just 10 percent of it was done as of September.

Hong's memories of the To Lich River – one that that exuded serenity as a burning sunset bathed in it – is a distant memory.

The majesty is gone, the serenity is gone, the water flow itself is gone. Today it is not even a shadow of itself – it is a foul sewer of trash and black sludge that no one dares to get close to without an air mask.

The river majestic is a creek pathetic.