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Water resources and environment in and around Ho Chi Minh City, Vietnam Hiep Nguyen Duc Environment Protection Authority, NSW, Australia Truong Phuoc Truong University of New South Wales, Australia ..................................... The increase in population, and rapid economic growth in recent years, after Doi Moi (Renovation) Policy, have put a large and increasing stress on the water resources and environment in Ho Chi Minh City, Vietnam. The demand from industries, businesses, and households surpassed the current supply distribution capacities. The water quality in river courses and underground sources is also highly degraded due to many sources of pollution. The authorities have initiated some joint venture works with foreign water companies to invest in the commercial development of water supply infrastructure. In this paper, the status of water environment and water resources in and around the city is described. Various environment organizations have responded to the problems of water pollution. Of interest are the emerging roles of non-government organizations (NGO) and of public participation in environment issues, especially in a traditionally government-controlled society. Some suggestions for improvement of water management are also proposed. Ho Chi Minh City is the largest city in Vietnam with a current (1995) population of about 5 million and which is increasing rapidly due to internal migration and na tural growth. The city covers an area of 2,056 sq km, which is about 0.61% of the total country area and a population density of 2,338 persons/sq km (see Figure 1). 1,2 With rapid economic growth following the opening of the Vietnamese economy after "Doi Mo i" or "Renovation Policy" in 1987 and the end of the U.S. trade embargo in 1994, water demand in the City has been increasing rapidly. This has caused considerable stress on the environment. The Ho Chi Minh City Service of Communication and Public Works (SCPW) admitted in September 1998 that the city's decades-old water supply system is incapable of meeting the growing demand. According to the SCPW, the water consumption is estimated to be 800,000 cubic meters per day, but the combined daily capacity of its two water treatment plants at Thu Duc and Hoc Mon, and of underground wells in the city, stops short at 750,000 cubic meters. In addition, if water loss in delivery is taken into account (the proportion of water loss can be as high as 32% in some areas), then only about 500,000 cubic meters are available for use each day. In 2000, in fact, the daily water demand jumped up to 1,250,000 cubic meters /day while the supply capacity of Water Supply Company could only reach 850,000 cubic meters/day. 3 This is despite the fact that the City is situated in an area where water resources are plentiful and potential supply should be able to meet the increased demand even with sustained urban growth if the water resources are properly developed and managed. Ho Chi Minh City is situated next to the Saigon River, which joins the Dong Nai River to make northern and eastern boundaries of the city. These waterways can act both as potential water supply resources and as a medium to carry away the wastewater. The Dong Nai River has a minimum flow of approximately 100 cubic meters/sec. It originates from the central highlands of Vietnam and flows through Dong Nai and Ho Chi Minh City with tributaries from other provinces. The total catchment area is 42,665 sq km and total flow volume is 30.6 cu km/year. 4 Forests cover approximately 30% of the basin. The upstream area in the lowland part of the river is the present Cat Tien National Park. The Tri An reservoir and hydropower plant is located downstream nearby. Further downstream of the river it is joined at Nha Be area of Ho Chi Minh City by the Saigon River. Inside the city a hydrological network of five canals acts as the natural water drainage 5: Nhieu Loc - Thi Nghe (9 km), Tau Hu - Kinh Doi - Kinh Te (19.5 km), Ben Nghe (5.9 km), Tan Hoa - Ong Buong - Lo Gom (7.2 km), and Tham Luong - Ben Cat - Vam Thuat (14 km). Before finally reaching the sea, the Dong Nai River passes through a coastal mangrove forested delta area with many interconnecting riverlets. This Can Gio area is the "green lungs" of Ho Chi Minh City. This 75,740 ha area is rich in biodiversity and was designated in 2000 as a Man and Biosphere (MAB) Mangrove Reserve area by UNESCO. Figure 1. Ho Chi Minh City and surrounding areas (Source: ESRI World map) Water Environment and Pollution One of the important aspects of water resource usage management is the prevention and mitigation of sources of pollution into the watercourses. A brief description of the current water environment and pollution is presented below. Sources of Pollution The majority of industries are located in industrial zones around Ho Chi Minh City. In addition to old industrial zones such as Bien Hoa zone 1, built in 1963, a large number of new industrial zones were set up recently in the neighboring provinces of Dong Nai, Song Be, and Ba Ria-Vung Tau. They were established to attract foreign investment to set up factories to produce goods for domestic and export markets. The industrial zone in Bien Hoa (Dong Nai) is upstream from the Ho Chi Minh City. The foremost concern is that the wastewater discharge from this zone to the Dong Nai River is near the Hoa An pumping station which supplies water to the residents of Ho Chi Minh City. 6 Altogether, it was estimated that about 200,000 cubic meters/day of wastewater is discharged into the Dong Nai-Saigon River from the industrial zones. 7 In early April 2000, more than 50 tonnes of fish were killed in an upstream feeder of the Tri An Reservoir in the upper reach of the Dong Nai River. The Dong Nai River provides drinking water for most of the residents of Ho Chi Minh City and the surrounding provinces. The main suspects for the pollution were two agro-industrial plants, the La Nga Sugar Cane Company and the Mauri La Nga Food Fermentation Joint Venture Company. 8 Another source of pollution in the Dong Nai-Saigon catchment and watershed is agricultural run-off from the high usage of chemical and organic fertilizers and widespread use of pesticides. 2 In Truong Tho, Thu Duc district, residents near the industrial zone have suffered from the problem of severe creek and groundwater pollution, which results from the discharge from a number of sources. Their farms suffered from vegetable and animal losses. There are reports of fish dying off in ponds. Odors emanating from polluted water have also made living condition worse. 9 Each day, about 7,000 cubic meters of untreated wastewater from 10 factories are discharged into the receiving creek, which flow on to waterways in the residential area before eventually reaching the Saigon River. In 2001 it was reported that companies such as Phuoc Long Textile company, the seafood processing company Cofidec, and the Mai Tan Paper Company discharged about 1500 cubic meters, 90 cubic meters, and 200 cubic meters of untreated wastewater respectively into the water environment daily. While the sources of the industrial discharges are located mostly in the Thu Duc and Bien Hoa areas, their discharges are eventually found scattered along the many canals in and around Ho Chi Minh City. There are five main canal systems that receive direct wastes from various sources: Nhieu Loc- Thi Nghe, Tau Hu-Ben Nghe, Doi-Te, Tan Hoa-Lo Gom, and Tham Luong- Vam Thuat. The total length of these canal systems is about 56 km with about 100 km from smaller tributaries. According to the data provided by the Water Supply Company, there are about 461,000 cubic meters of wastewater discharged into the canal systems daily 6 coming from 680 factories and 22,562 small manufacturing enterprises operating in the city in 1997. Nearly all of these wastewater sources are not equipped with any wastewater treatment facilities. Wastewater samples collected from some of the food-processing plants (numbering about 100) situated in and around the city area were analyzed by the Geographic and Geological Society of Ho Chi Minh City, and the results showed that the BOD (biological oxygen demand) levels ranged from 300 to 2800 mg/l which is 3 to 28 times above the Vietnamese standard (TCVN 5945). This is the standard for class C wastewater which would be allowed to be discharged into the environment. 6 According to a report by the Department of Science, Technology and Environment (DOSTE) to the HCM City People's Committee, most of the 57 factories of various types existing in the city discharge wastewater with high pollutant concentrations to the Tham Luong canal without any proper treatment. 10 This canal, flowing through districts 12, Tan Binh, and Go Vap, has been one of the most polluted canals in the city and the problem has been in existence for over 10 years. The health of the residents around the canal is thus severely affected with frequent outbreaks of dermatitis and gastroenteritis. The district most affected, District 12, has began taken action to reduce the wastewater discharge problem. Most enterprises in district 12 now have wastewater treatment. Recently (June 2001) the local government in the Go Vap District has also demanded that industrial sites in the district should treat wastewater before discharging to the Tham Luong canal. Other local governments in the districts surrounding the canal have also asked the HCM city DOSTE to inspect and take action agains t companies that fail to treat wastewater properly.

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