Minimizing health risks associated with wastewater and excreta use in urban and periurban vegetable

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Minimizing health risks associated with
wastewater and excreta use in urban and
peri-urban vegetable farming in Ghana 1Abaidoo,
R.C., Drechsel, P., Amoah, P., Keraita, B. and
Gordana Kranjac-Berisavljevic 1KNUST, KUMASI,
GHANA
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Wastewater

• Domestic sources/grey water
• Human excreta
• Solid waste
• Industrial wastewater
• Storm water

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Farmers reason for use of wastewater/excreta

• Urban/peri-urban farming- only source of
  livelihood
• Source of nutrients for their crop
• Soil fertility management
• Fresh water and mineral fertilizers are
  unavailable and expensive

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But they also know that--------

• Practice has high public health risk potential

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Facts

• Sewerage network serves only 4.5 of
  population in the cities
• Open defecation unacceptable but common
• Wastewater from domestic sources end up in urban
  drains and water bodies
• Faecal coliform and helminth egg populations in
  such water can be extremely high
• Urban centres have no sustainable means of
  treating wastewater

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Examples of wastewater collection points
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Farmers create collection points
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On vegetables usually eaten uncooked
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Facts.

• Faecal contamination levels on such vegetables
  can be high (3-8 log units)
• Potential for transmission of excreta-related
  diseases affecting human health is high
• City authorities unsuccessful attempts to ban
  wastewater use in vegetable production

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Use of faecal sludge in agriculture (Tamale
municipality)
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Discharge of sludge into a pit created by farmers
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Direct discharge onto fields
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• Who is at risk?

• Working classes and school children
• Wastewater irrigated vegetable farmers and their
  family
• Market women and workers of the fast
  food/restaurant sector
• Household consumers

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Exposure of farmers and children
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Our approach

• Reduce risks associated with use of excreta and
  excreta contaminated water in peri-urban
  agriculture

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• Adopting WHO paradigm
• Constructing multiple barriers along the
  production-consumption chain by using various
  risk management strategies and interventions

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Microbial contamination
On-farm Alternative water sources Water
treatment Change of irrigation methods Management
based measures
ASSESSMENT
Risk perceptions and awareness
MANAGEMENT
Post-harvest Vegetable handling Washing methods
Guidelines for best practices
Hygiene education FFS Washing hands Food
handling
KNOWLEDGE SHARING
Training modules and raising awareness
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• Feasibility assessments for selected options for
  optimal health protection
• Economic, legal, and social
• Development of Institutional framework
• Capacity building

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• Our Partners
• University of Development Studies, Tamale, Ghana
• Government Departments
• IWMI, International Water Management Institute,
  West Africa Office (Accra and Kumasi)
• University of Copenhagen
• WHO/IDRC/FAO/CPWF

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• Book reference
• Obuobie, E., Keraita, B., Danso, G., Amoah, P.,
  Cofie, O.O., Rachid-Sally, L. and Drechsel, P.
  2006. Irrigated urban vegetable production in
  Ghana Characteristics, benefits and risks.
  IWMI-RAUF-CPWF, Accra, Ghana QWMI, 150 pp.

www.cityfarmer.org/GhanaIrrigateVegis.html