The cleaning operations in Cau Giay District are expected to cost the most at nearly VND11 billion ($472,800), followed by Ba Vi District at VND7.8 billion ($335,260). Dong Anh District will take the smallest allocation of around VND500 million ($21,500).

The Hanoi People's Committee has required site cleaning staff to comply with environmental sanitation guidelines and avoid both overlaps with the operation of the city's sweeping trucks and operating on rainy days.

Main streets which generate the most dirt will be washed more often. Local authorities will decide which streets need less washing depending on the amount of heat and air pollution levels on given days.

Hanoi had the most polluted air in Vietnam last month, according to a report by Vietnam Environment Administration which showed the city's PM2.5 level at 22-48 μg/m3, compared to 8-30 μg/m3 in Ho Chi Minh City. PM2.5, also described as super fine particles, is a fraction of the width of a human hair and comes from vehicles and factories and natural sources like dust.

Hanoi’s popular walking street zone around the Sword Lake will be washed three times a week. Water trucks will spray main streets with a lot of traffic like Ly Thuong Kiet, Tran Hung Dao and Hai Ba Trung Streets on a daily basis. Streets where water trucks need to operate to keep illegal bike races at bay will be washed four times a week.

In other major areas, Ba Dinh District plans to clean most of its 37 streets once a week, while Cau Giay District’s 50 or so streets will be cleaned every day.

Most of Hanoi’s outskirt districts like Dong Anh, Thuong Tin and Me Linh will not receive the same amount of cleaning.

The city had grounded water trucks in early 2017, with Chairman Nguyen Duc Chung saying washing did not make the city any cleaner.

Fifty vehicles that vacuum dust and trash were then bought from Germany. Each collects 1.5 cubic meters of dust a day, the same volume as 12 workers.

Chung had said then that using such vehicles will save the city VND70 billion ($3 million) in washing its streets with water each year, while reducing the workload of drainage maintenance staff who would have to remove mud collected in the system by the washing.

Since then, the cleaning trucks have only been used by the Hanoi Urban Environment Company (URENCO) when the city hosts a large event and to clean the streets around the Sword Lake before and after weekends, when they become exclusively pedestrian.

The decision to deploy the water trucks again was taken late last year after numerous reports about worsening air pollution since September.