WASTEWATER MANAGEMENT (WWM) AND ITS IMPACTS TO WATER ENVIRONMENTS IN VIETNAM. WWM CONCEPTS AND TECHNOLOGIES Hanoi University of Civil Engineering, 1 Cities in Vietnam, classes I - V Population, mln. Urban population ratio in Vietnam Total population, m ln. 120 urban population, m ln. 100 80 60 40 20 0 2000 2010 2020 Years Years Total population, mln. Urban population, mln. % 2000 2010 2020 76 93 103 15 30.4 46 20 33 45 2 Rapid urbanization and industrialization Hanoi city: Population 1945: 280,000 1954: 380,000 1960: 1,050,000 2001: 1,700,000 among 2,750,000 total urban zone population 2020: 2.5 million among 4.5 millions total urban zone population The area of Hanoi urban in 1994 was 4,600 ha, in 2000: 9,000 ha, and it will be up to 25,000 ha in 2020 Industrial ratio from GDP, % 400,000 200,000 36.0 1990 1995 1999 2000 Years 1999 2000 Years Years 3 1994 1998 1992 1997 1990 1996 1988 0.0 1986 32.0 1.0 1984 1918 2.0 1982 0 34.0 3.0 1980 4.0 1978 5.0 38.0 600,000 1969 6.0 800,000 1954 7.0 Industrial ratio from GDP, % 1,000,000 1939 8.0 40.0 1,200,000 1928 Agricultural ratio from GDP, % 9.0 % GDP % GDP Agricultural ratio from GDP, % Population, inh. Hanoi inner-city population (4 districts), 1918 - 1994 Rapid urbanization and industrialization Urbanization and industrialization processes create pressures on the environment and natural resources; destroy the ecological balance, impact on environmental quality and natural resources These pressures could exceed the “enduring ability” of the environment and natural resources as well as the “response ability” 4 Pressure-Status-Response (PSR) Model (Adopted from EPA) Pressures Pressures Environment, natural resources Production, Commerce, Consumption Environmental status Air, Water, Soil, Natural resources, Ecosystems, Urban and rural areas Energy, Transport, Industries, Agriculture, Forestry, etc. Information Information Responses Decisions, Actions Response Responses Decisions, Actions Legislations, Strategies, Policies, New technologies, Pollution control, Consumption change Conventions, etc. 5 Water resources Surface water resources: 2360 rivers with lengths over 10 km accounting for a total flow of 835 Billion m3 Year 2000: 4700 m3 person yr-1 (global average: 7400 m3 person yr-1) Not equally distributed by locality or season: - 5 months wet season: 75 - 80% of total flow - 7 months dry season: 20 - 25% of total flow 6 Ground water: 50 - 60 Billion m3 of total potential Maximum available for exploitation: 10 - 12 Billion m3 7 8 Hanoi water supply Water supply in Hanoi city Water demand, cmpd 1,200,000 1,000,000 800,000 600,000 400,000 200,000 0 2001 Ground water 2005 2020 Year Surface water (Red river) 9 Groundwater over-exploitation has caused depression and subsidence phenomenon in some areas of Hanoi city • The highest rate of subsidence (30 mm yr-1) has been found in a 2-km2 radius surrounding Phap Van water treatment plant Groundwater in Pleistocene (QII) aquifer has been slightly polluted by nitrogen compounds, especially by ammonia, which has being found at Ha Dinh, Tuong Mai and Phap Van water treatment plants (up to 20 mg NH4-N l-1) 10 Domestic water use 640 cities and towns with a population of 18 Million (23%) 200 urban water supply projects, provide 2.7 Million m3 d-1 for 60% of the urban population this is equivalent to 60-80 l d-1 40% of the urban population does not have access to an adequate water supply 90% urban areas are not equipped with adequate sewerage systems 1995: 28% population in rural areas served by clean water 1999: 36% 2002: 50% receiving 50 l d-1 11 Water use for agriculture 1990: 47 Billion m3 (90% of total water consumption) 1999: 60 Billion m3 (85% of total) 12 Water use for industrial activities 1990: 5.33 Billion m3 (9.8% of total water consumption) 1999: 14 Billion m3 (15% of total) 13 Industrial wastewaters 90% of industrial enterprises do not meet National effluent standards 73% of industrial enterprises do not have WW treatment systems 60% of WW treatment systems are not operated properly 14 Water quality of river basins Red river delta: Organics pollution Domestic wastewater is a major pollution source, among domestic, industrial and agricultural activities Rivers in Central Vietnam: Affordable quality Lightly affected by salt intrusion due to tidal regime Rivers in the Southern Vietnam: Increasing levels of organic and inorganic pollutants Sai Gon, Dong Nai, Thi Vai rivers, etc. 15 16 Water environment problems Flooding Salt intrusion Pollution 17 Monitoring data: 1995 - 2001 Variables Measured: Temp, pH, BOD5, COD, SS, TDS, EC, DO,NH4+, NO3-, PO43-, Cl-, Fe, Pb, Cd, (Cr, Hg, As), Coliform. BOD5 , COD, NH+4, NO-3 are generally 2 – 4 times higher than the permissible value Total coli-form is 100 times higher than the permissible value In some places Pb and Hg concentrations were several times higher than permissible value Some rivers are effectively drainage channels 18 Pollution of surface water has increasd NH4, mg/l BOD5, mg/l 150.00 100.00 50.00 25.00 20.00 15.00 10.00 5.00 0.00 0.00 1995 1996 1997 1998 1999 2000 2001 To Lich River, at New Bridge Kim Nguu River, at Yen So Gate Years 1995 1996 1997 1998 1999 2000 2001 To Lich River, at New Bridge Kim Nguu River, at Yen So Gate Years 19 Wastewater re-use in agriculture 20 Untreated faecal sludge use in aquaculture 21 Pesticides Before 1985: 0.3 kg ha-1 1986 – 1990: 0.4 – 0.5 kg ha-1 1995: 0.85 kg ha-1 1999 - 2000: 1.12 kg ha-1 Concentrated in Red and Mekong River deltas Improper use 22 Fertilizer 5 Million t yr-1 inorganic fertilizers including 3 Million t yr-1 of imported fertilizers Vietnam: 80-90 kg inorganic fertilizer ha (Rice = 100 - 110 kg ha-1) 23 Mitigation measures Legislative base, economical tools Environmental standards Urban planning and management Pollution control technologies Education and public awareness 24 Standards Water quality TCVN 5942:1995 TCVN 5943:1995 TCVN 5944:1995 Discharges TCVN 5945:1995 TCVN 6773:2000 TCVN 6980:2001 TCVN 6982:2001 TCVN 6984:2001 TCVN 6986:2001 Reuse: (WHO) Stepwise approach! TCVN 6772:2000 TCVN 6774:2000 TCVN 6981:2001 TCVN 6983:2001 TCVN 6985:2001 TCVN 6987:2001 25 “Critical Control Points” as barriers against disease transmission Person-toperson Dishes Dom. animals, rodents Pathogens in faeces Flies Food Soil Fish Water Containment, treatment 26 Barriers: improved excreta disposal, hygiene and waste management Planning DEWATS concepts vs centralized WW systems IC’s: “Flush-and-Discharge” (all mixed) Facets 27 RURBIFARM Project Sustainable Farming at the rural-urban interface. Introduction to the NISF research sites in Hanoi, Vietnam by NISF team What is peri-urban agriculture? 1. 2. 3. Geographically close to cities. Agricultural production mainly for city use. City activities have a direct impact on rural activities. Two proposed NISF study sites: Tien Phong & Minh Khai Commune Hanoi meteorological 2000 (Lang station) Rainfall Evaporation 300 35 Temperature 30 250 mm 20 150 15 100 oC 25 200 10 50 5 0 0 1 2 3 4 5 6 7 8 9 10 11 12 month Inorganic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000 Year N P2O5 K2O Total Agricultural land (1000 ha) 1996 1997 1998 1999 2000 109.4 103.2 107.9 106.3 113.6 51.8 43.4 49.5 59.9 54.7 9.1 22.7 24.7 43.9 22.6 184.6 169.3 182.0 210.1 190.8 7681.2 7843.1 8080.2 8712.8 9345.3 Organic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000 Year 1996 1997 1998 1999 2000 N 43.2 43.4 42.9 40.8 39.2 P2O5 48.9 49.5 49.2 47.1 46.1 K2O 105.3 105.4 104.2 98.7 94.0 Total 197.4 198.3 196.2 186.6 197.4 Agricultural land 7681.2 7843.1 8080.2 8712.8 9345.3 (1000 ha) Tien Phong site Minh Khai site Overview of Hanoi city and the study area Degraded land (Acrisols) Tien Phong commune/A CIAR Minh Khai commune Fertile soil (Fluvisols) Minh Khai site (vegetable-FS) ACIAR/Tien Phong site (mixed FS) Land preparation for vegetable planting Irrigation work