Hanoi University of Civil Engineering, WASTEWATER MANAGEMENT (WWM) AND ITS IMPACTS TO WATER ENVIRONMENTS IN VIETNAM. WWM CONCEPTS AND TECHNOLOGIES Hanoi University of Civil Engineering,

Cities in Vietnam, classes I - V

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

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”

Pressure-Status-Response (PSR) Model (Adopted from EPA) Production, Commerce, Consumption Energy, Transport, Industries, Agriculture, Forestry, etc. Environmental status Air, Water, Soil, Natural resources, Ecosystems, Urban and rural areas Response Legislations, Strategies, Policies, New technologies, Pollution control, Consumption change Conventions, etc. ResponsesDecisions, Actions Environment, natural resources Information

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

Ground water: 50 - 60 Billion m3 of total potential Maximum available for exploitation: 10 - 12 Billion m3

Hanoi water supply

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)

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

Water use for agriculture 1990: 47 Billion m3 (90% of total water consumption) 1999: 60 Billion m3 (85% of total)

Water use for industrial activities 1990: 5.33 Billion m3 (9.8% of total water consumption) 1999: 14 Billion m3 (15% of total)

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

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.

Water environment problems Flooding Salt intrusion Pollution

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

Pollution of surface water has increasd

Wastewater re-use in agriculture

Untreated faecal sludge use in aquaculture

Pesticides Before 1985: 0.3 kg ha-1 1986 – 1990: 0.4 – 0.5 kg ha-1 Concentrated in Red and Mekong River deltas Improper use

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)

Mitigation measures Legislative base, economical tools Environmental standards Urban planning and management Pollution control technologies Education and public awareness

Standards Water quality Discharges TCVN 5942:1995 TCVN 5943:1995 Reuse: (WHO) Stepwise approach!

“Critical Control Points” as barriers against disease transmission Pathogens in faeces Person-to-person Flies Soil Dom. animals, rodents Water Dishes Food Fish Containment, treatment Barriers: improved excreta disposal, hygiene and waste management

Planning DEWATS concepts vs centralized WW systems

RURBIFARM Project Sustainable Farming at the rural-urban interface 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? 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) Inorganic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000 Organic fertilizers pressure in a ha of agricultural land in Vietnam from 1996 - 2000

Overview of Hanoi city and the study area Tien Phong site Minh Khai site

Fertile soil (Fluvisols) Degraded land (Acrisols) Tien Phong commune/ACIAR Minh Khai commune Fertile soil (Fluvisols)

Minh Khai site (vegetable-FS)

ACIAR/Tien Phong site (mixed FS)

Land preparation for vegetable planting

Irrigation work