Urban waste water runoff

In urban areas and industrial parks, about 3,110,000 m3 of domestic wastewater and production wastewater are discharged directly into surface water sources.

According to information from the Department of Environmental Protection (Ministry of Natural Resources and Environment), the system of ponds, lakes, canals and ditches in big cities is in serious pollution situation exceeding the permitted standards. 10 times; lakes in the inner city in the present big cities (Hanoi, Ho Chi Minh, Hai Phong, Hue) are mostly in eutrophication, many lakes are enriched with mutations and re-contaminated organically.

Urban: Filled with waste water

Nam Son Waste Treatment Zone, Hanoi
(Photo: Kieu Minh)

In addition, the concentration of pollutants (COD, total nitrogen, total phosphorus and heavy metals) in landfills or landfills is very high, water is large in color. When discharged into the environment, leachate often causes serious pollution to surface water bodies as well as surrounding groundwater.

Along with the above-mentioned types of waste water, about 1,000 hospitals and health centers (up to district level) release hundreds of thousands of cubic meters of untreated waste water every day. This is a source of hazardous waste which causes serious pollution to the environment.

Moreover, the annual amount of pesticide in agriculture is about 0.5-3.5kg / ha / crop, together with the amount of pesticides and mineral fertilizers in production activities, which also cause eutrophication or water poisoning. About 1,450 trade villages also create a quantity of waste discharged into the environment, seriously polluting the environment at many points, especially in villages producing paper, slaughtering cattle, weaving .

Specifically, in Hanoi, the total daily discharge of domestic wastewater is about 450,000m ³ / day and night; waste water from production and service establishments poured into the city drainage system about 260,000 ^m3 / day; Hanoi's urban rivers have been polluted, especially waste water rivers like Kim Nguu and To Lich . these rivers are no longer self-cleaning. The quality of water in urban lakes is also not up to the standard, allowing for B-type due to organic pollution.

Ho Chi Minh City, with about 1,000 industrial enterprises and more than 22,000 handicraft production facilities, many of which do not have waste treatment systems leading to organic and microbial contamination of surface water. .

Waterway transport is also the cause of oil pollution, acidification in the Saigon River and Dong Nai River along with the causes of water pollution and alum soil improvement in the area, using mineral fertilizers with sour characteristics. . In which the pollution level of Saigon River tends to increase gradually downstream.

In some other urban areas (Hai Phong, Hue, Ha Long, Vinh), there are no rivers that meet the standards for type A permission.

Waste water treatment has not met the requirements of urban development

Waste treatment with advanced technology
(Photo: Kieu Minh)

According to the Department of Environmental Protection, our country currently does not have any landfill site with a leachate treatment system to ensure environmental standards according to Vietnam standards 5945-1995.

Meanwhile, among 76 industrial parks (IPs) and export processing zones, there are only 16 centralized wastewater treatment stations operating at a capacity of 41,800m3 / day. The wastewater treatment technology is mainly biological or chemical combined with biology. The amount of industrial wastewater treated to ensure environmental standards is very low (4.26%).

Dr. Hoang Duong Tung, Department of Environmental Protection said, currently only some cities such as Hanoi, Ho Chi Minh City, Da Nang and Ha Long . have wastewater treatment stations of all kinds with the above capacity. 5,000m ³ / day is in the design and construction phase, no station has come into operation. Some other cities and towns are also developing urban wastewater treatment projects with funding from international organizations and projects.

As mentioned above, wastewater treatment has not been promoted, in some urban areas there are also some local wastewater treatment stations for such hospitals (Hanoi, Hai Phong, Quang Ninh, Hue). , Da Nang .) but due to many reasons such as design, operation, maintenance, no funding . but many treatment stations after a short period of operations have degraded and stopped working.

For concentrated industrial zones, according to regulations, it is required to build a wastewater treatment station to ensure TCVN 5945-95, but these IPs have built a very limited centralized wastewater collection and treatment system; Wastewater treatment stations are also intermittent, dealing, and the quality of treatment is not high.

Deputy Director of Department of Urban Infrastructure Bui Xuan Doan said that it is necessary to implement a synchronous plan to unify water drainage and wastewater treatment planning in big urban areas with the formulation of regional construction planning. Ha Noi capital,

The Ho Chi Minh City region, key economic regions, makes provincial planning for provinces without planning. In particular, focus on measures to research and apply scientific and technical advances, using advanced wastewater treatment technology, in accordance with Vietnam's economic development conditions; mobilize domestic capital sources and ODA capital for investment in construction of water drainage and wastewater treatment systems.

Kieu Minh