Vietnam Case study

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Vietnam Case study

• and the
• Pitfalls in conducting a national assessment on
  wastewater use in agriculture

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Vietnam with a rainfall of 1700 to 2000 mm, its
population of 77 mill. residing on 333000
km2.What is the significance of wastewater
use for agriculture and aquaculture?
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Survey of 30 major cities in Vietnam

• explores the extent of urban wastewater use and
  analyzes the main causes and consequences of its
  use in Vietnamese urban and peri-urban
  agriculture and aquaculture.
• This is the first phase of a longer term study
  proposed to be carried out in Vietnam with the
  aim to improve the understanding of the use of
  wastewater in agriculture and aquaculture, and
  its health and environmental impacts in the
  context of integrated water resources management

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The scope of nationwide survey covers

• Water supply information
• Sanitation and sewerage infrastructure
• Wastewater related information sources,
  management
• Production information on agriculture and
  aquaculture in wastewater use area
• General Social health and crop impact Information
  

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Stratification scheme for selection of sample

• 57 provinces 4 major cities
• 8 agro-ecological
• Criteria for selection
• Population, accessibility, exclude no ww areas
  and southern floodplains
• 30 cities selected covering 7 agro-ecological
  zones (northwest mountainous region excluded)

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Cities selected
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Metropolitan area urban center
suburban areas Information
researched

• Water supply and sanitation infrastructure
  volumes
• Main industrial act. Connection to sewers, type
  of ind.activity, proportion of ind.ww,
• Treatment facility status, presence of natural
  ponds, use

• ww irrigated areas, extents, cropping pattern,
  sources of water
• Aquaculture volumes, production
• Livelihoods agri, aqua
• Reasons for use, non-use
• Payment for ww

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Urban wastewater blackwater, greywater,
industrial, commercial, run-off
Definitions

• Irrigated areas where wastewater is used directly
  from ww canal or just downstream of a discharge
  point after dilution through discharge into
  surface water.
• Wastewater drainage canal
• Drainage canal of an irrigation system receiving
  wastewater
• Irrigation canal receiving wastewater

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Methodology

• 1 pilot city to refine questionnaire
• Fieldwork reqd. 3 months (Aug Oct) with 3
  teams, 7 staff members
• In depth interviews with officials
• Dept. Land administration
• Dept of Statistics
• Dept. Agriculture and Rural Development
• Irrigation and Drainage Management, Company
• Dept. of Science, Technology, and Environment
• Data analysis categorisation by class and
  regions, using excel worksheets

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Classes of cities and population
Water supply 40 (cities) surface, 17 ground,
43 both
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Wastewater by city class
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Water wastewater by region
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Setting the context Pattern and extent of
wastewater use

• 28/30 cities ie 93 use wastewater either for
  agriculture or aquaculture or both
• In these 28 cities
• 80 use for agriculture
• 63 for aquaculture
• Exception Haiphong with gt 45 agri. land, but no
  ww use

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Agricultural land use

• 5 of 6 cities with agriculture land exceeding
  10000 ha are in high population cities
• Ratio of agri. land to total land exceeds 45 for
  3 out of 4 of the largest cities
• ? importance of urban/peri-urban agriculture

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Agri. land and ww agriculture by class
excludes NinhBinh
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Agri. land and ww agriculture by region
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Cropping pattern by region
only one city - Tanan
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Why use wastewater for agriculture?

• Unplanned discharge into natural water courses,
  drainage canals or irrigation canals irrigation
  with wastewater unavoidable
• Wastewater is diluted sewage mostly
• 9/24 cities recognised the nutrient and water
  value
• lt10 of available wastewater used for
  agriculture

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Aquaculture using wastewater

• 19/30 cities use ww for aquaculture usually in
  natural ponds
• Wastewater fish production 6358 t/y of which
  3380 tons is from Hanoi
• HCMH no fish farming with wastewater but fish
  production is from contaminated water bodies
  including river.

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Livelihoods by city class
HH info.unavailable for some cities HH x 5
no. of persons
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Livelihoods by region
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Natural ponds for treatment

• Originally designed for flood control primarily
• now receives wastewater
• 16 cities with pond areas exceeding 10 ha
• Retention times vary between 1-122
• 14 cities are under 13 days
• EFFECTIVENESS is questionable without monitoring

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Health environment

• No substantive evaluation of H E impacts but
  perceptions recorded
• More than half the local authorities interviewed
  were aware of negative impacts
• Preference for alternative sources if available
  but no plans for this
• Use of ww not actively discouraged

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Conclusions

• In water rich countries, reliability and
  availability factors do not influence decision
  for its use
• In larger cities urban/peri-urban agriculture
  plays an important role in providing food for
  cities
• Out of 35 agricultural land nearly 2 is
  irrigated with wastewater
• ( 5000 ha for 30 cities)

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Conclusions

• Wastewater agriculture and aquaculture provide
  llivelihoods for 1 and 0.1 respectively of
  the population
• (aquaculture 1/10 agriculture)
• Smaller cities which produce lower volumes of ww
  have a higher of ww agriculture other factors
  influence use

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Conclusions ( contd)

• Paddy is the predominant crop in ww irrigated
  areas for Vietnam
• From cropping pattern it is clear that there is
  very little use of wastewater in winter season
• Natural ponds used for flood control now serve
  treatment purpose as well. Design parameters for
  treatment not met.

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Lessons relevant to typology and national
assessments

• Clear typology required for common understanding
  we nearly met our waterloo in vietnam!!
• Explain the term wastewater (level of
  pollution). In Vietnam we defined what was meant
  by wastewater that was used
• Well trained surveyors/teams with clear
  understanding of terminology and typology
  essential

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Lessons relevant to typology and national
assessments

• Provide clear guidelines for completing
  questionnaire for every question an explanation
• Proposed Questionnaire for NAs very
  comprehensive. Data collection at national level
  time consuming
• At city level, in data short countries, avoid
  seeking information that is confusing or
  difficult to obtain, unless investigators are
  trained

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Thank you..

• Doan Tuan and his team from CIWSR, Vietnam
• Phung Dac Cam and his team, NIHE
• KVL, Copenhagen
• DHI, Denmark
• Univ. of Copenhagen
• DANIDA