International Standard and Guidelines: Health and Agriculture Aspects

1
International Standard and Guidelines Health and
Agriculture Aspects
(Ecological Sanitation Symposium, Syria,
11-13.12.2005)

• Christine Werner
• Deutsche Gesellschaft für Technische
  Zusammenarbeit (GTZ) GmbH
• ecological sanitation program, Division 44
  environment and infrastructure

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Contents

• WHO Guidelines
• 1989 version Guidelines for the safe use of
  wastewater and excreta in agriculture and
  aquaculture
• 2005 version (upcoming) Guidelines for the safe
  use of wastewater, excreta and greywater
• EcoSanRes Guidelines
• Guidelines on  the safe use of urine and faeces
  in ecological sanitation systems
• Guidelines on the use of urine and faeces in crop
  production
• FAO Guidelines
• FAO irrigation and drainage paper 47 wastewater
  treatment and use in agriculture (1992)

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WHO guidelines for the safe use of wastewater and
excreta in agriculture and aquaculture (1989)
Category Use Person / Group exposed NematodesEggs / kg Feacal coliformsnumber / 100 g
A Application to field crop (used for raw food) worker, consumer, public lt/ 1 lt/ 1000
B Application to field crop (for industrial use, feedstock, trees) worker lt/ 1 no suggested standard
C Local application to field crop of cat. B, without contact to persons none not relevant not relevant
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New WHO guidelines for the safe use of
wastewater, excreta and greywater

• Upcoming WHO guidelines, update of the guidelines
  from 1989, publication planned in 2006
• 3 Volumes
• safe use of wastewater in agriculture
• safe use of wastewater in aquaculture
• safe use of excreta and greywater

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New WHO guidelines for the safe use of
wastewater, excreta and greywater

• Reuse of wastewater, greywater and excreta in
  agriculture and aquaculture is practiced
  worldwide on a large scale, however often without
  sufficient health proctction measures
• WHO recognise the importance of reuse of
  wastewater, greywater and excreta for sustainable
  food production and improved livelihood
• WHO provides guidance on health protection
  measures for safe reuse
• WHO recognise source-separation as a special and
  valid approach

source GTZ
6
New WHO guidelines for the safe use of
wastewater, excreta and greywater

• The new WHO-guidelines are
• based on
• scientific consensus and best available evidence,
• health based targets
• good practices and a multiple-barrier approach
• to be adapted to local social, economic, and
  environmental factors
• striving to maximize overall public health
  benefits and the beneficial use of scarce
  resources

source GTZ
source GTZ
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new WHO guidelines for the safe use of
wastewater, excreta and greywater

• key issue better methodologies for evaluating
  risk
• previous guidelines were based on actual risks
  using epidemiological evidence
• updated guidelines make use of all available
  evidence including Quantitative Microbial Risk
  Assessment (QMRA-models)
• data on different pathogens are used to develop
• health based targets,
• required pathogen reduction and
• miocrobial performance targets of wastewater and
  excreta treatment systems

source GTZ
source GTZ
8
New WHO guidelines for the safe use of
wastewater, excreta and greywater

• Definition Disability Adjusted Life Years
  (DALYs)
• DALYs are a measure of population health in terms
  of the burden due to a specific disease or risk
  factor.
• DALYs attempt to measure healthy years of life
  lost because of disability or death from a
  disease
• DALYs account for not only acute health effects
  but also for delayed and chronic effects
• different health outcomes (e.g., cancer vs
  diarrhea) can be compared and risk management
  decisions can be prioritized.
• adopted protection level for wastewater/excreta
  use in agriculture in the new WHO
  guideline tolerable additional disease burden
  lt 10-6 DALYs or 1 µDaly per person and year
  only one of a million human life years
  expectancy will be lost due to the potential
  additional disease from wastewater/excreta
  reuse same protection level as used in the
  WHO guideline for drinking water

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New WHO guidelines for the safe use of
wastewater, excreta and greywater

• Pathogen reductions achievable by various health
  protection measures for wastewater use in
  agriculture

Control measure Pathogen reduction (log units)
Wastewater treatment 1-6
Localized (drip) irrigation (low-growing crops) 2
Localized (drip) irrigation (high-growing crops) 4
Spray drift control (spray irrigation) 1
Spray buffer zone (spray irrigation) 1
Pathogen die-off 0.5-2 per day
Produce washing with water 1
Produce disinfection 2
Produce peeling 2
Produce cooking 6-7
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New WHO guidelines for the safe use of
wastewater, excreta and greywater
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Verification monitoring of wastewater treatment
for the various levels of wastewater treatment in
Options A-G E.coli
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Health-based targets for treated wastewater use
in agriculture helminth eggs
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Example agricultural use of wastewater, Peru

• Coastal region of Peru extremely arid
• Wastewater treatment in stabilisation ponds
• Irrigation with treated effluent for restricted
  crops

source Saniplan
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Example greywater recycling through sub-surface
application, India

• Use of greywater in mulch trenches

Mulch filled trench or pit
source GTZ
15
Guidelines on  the safe use of urine and faeces
in ecological sanitation systems (EcoSanRes)

• public health issues of agricultural reuse of
  urine and faeces

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guidelines on  the safe use of urine and faeces
in ecological sanitation systems (EcoSanRes)

• focuses on the treatment and handling of faeces
  and urine, provides current information on risk
  management and assessment of source separation
  strategies
• technical and behavioural barriers against
  disease transmission, sanitation treatment
  methods, reuse in agriculture
• the scope of guideline is limited to products
  from urine diversion devices and dry collection
  systems for faeces.

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Guidelines on  the safe use of urine and faeces
in ecological sanitation systems (EcoSanRes)

• Recommendations for urine treatment and use
• The main risks in the use of excreta are related
  to the faecal fraction and not the urine
  fraction.
• Technical constructions should be done in ways to
  minimize faecal crosscontamination.
• At household level the urine can be used
  directly.
• Urine should, in large-scale systems, be stored
  for one month at 20C before use.

• A withholding period of one month between
  fertilization and harvest should be applied.
• Urine should be applied close to ground and
  preferably mixed with or watered into the soil.

Urine strogae in Sweden (Gebers)
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Guidelines on  the safe use of urine and faeces
in ecological sanitation systems (EcoSanRes)

• Recommendations for faeces treatment and use
• Faeces should be treated before use as
  fertilizer.
• Primary treatment (in the toilet) includes
  storage and alkaline treatment by addition of
  ash, lime or urea.
• 1-2 cups (200-500 ml enough to cover the fresh
  faeces) of alkaline material should be added
  after each defecation.

• Faeces should additionally be mixed into the soil
  in such a way that they are well covered.
• Faeces should not be used for fertilization of
  vegetables, fruits or root crops that are to be
  consumed raw, excluding fruit trees.

Dried faeces (GTZ))
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Guidelines on  the safe use of urine and faeces
in ecological sanitation systems (EcoSanRes)

• Recommended storage time and treatment for faeces

Treatment Criteria Comment
Storage (only treatment) at ambient temperature 2-20C 1,5-2 years Will eliminate most bacterial pathogens, substantially reduce viruses, protozoa and parasites, some ova may persist
Storage (only treatment) at 20-35C gt1 year As above
Storage and alkaline treatment pH gt9 during gt 6 months Temperature lt35, moisture content gt25 or lower pH will prolong the time for absolute elimination
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Guidelines on the use of urine and faeces in crop
production (EcoSanRes)

• Agronomic issues of agricultural reuse of urine
  and faeces

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Guidelines on the use of urine and faeces in crop
production (EcoSanRes)

• Requirements regarding re-using of excreta for
  agricultural purposes, including plant growth,
  nutirents in excreta, hygiene treatment of urine
  and faeces, etc. are discussed.
• Recommendations on using excreta in cultivation
  are given.
• It emphasizes that urine and faeces are complete
  fertilizers. Urine is rich in nitrogen and faeces
  are rich in phosphorous, potassium and organic
  matter.
• guideline is limited to products from urine
  diversion devices and dry collection systems for
  faeces.

source GTZ
source GTZ
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Guidelines on the use of urine and faeces in crop
production (EcoSanRes)

• Recommendations for use of urine in cultivation
• Urine is a quick-acting nitrogen-rich complete
  fertilizer. Best effects from prior to sowing, up
  until two-thirds of the period between sowing and
  harvest.
• Recommended application rate and time should be
  based on the desired nitrogen application rate
  (based on local recommendations for chemical
  nitrogen fertilizers)
• Rule of thumb apply the urine from one person
  during one day (24 hours) to one square metre of
  crop. ( 300-400 m2 per person and year)

Fotos Urine reuse in Havanna, Cuba (GTZ)
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Guidelines on the use of urine and faeces in crop
production (EcoSanRes)

• Recommendations for use of faeces in
  cultivation
• Faeces should be applied and mixed into the soil
  before cultivation starts. Local application in
  holes or furrows close to the planned plants
  allows for economic use
• The application rate can be based on the current
  recommendation for the use of phosphorous-based
  fertilizers (low application rate with little
  improvement due to the added organic matter)
• Faeces can also be applied at much higher rates
  for improving structure and water-holding
  capacity of the soil

source GTZ
Fotos Compost from faeces in Havanna, Cuba (GTZ)
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Beneficial effects of agricultural use of urine
and faeces
source GTZ
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FAO irrigation and drainage paper 47 Wastewater
treatment and use in agriculture

• Covers health aspects and agronomic aspects of
  reuse of wastewater in agriculture
• Draws on the WHO Guidelines (1989) for health
  protection measures

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FAO irrigation and drainage paper 47 Wastewater
treatment and use in agriculture

• FAO guidelines define use restrictions with
  respect to salinity, trace elements, nitrogen,
  etc. in order to not produce negative effects on
  productivity and yields.
• Blending conventional water with treated
  effluent, or using the two sources in rotation is
  possible.
• This means that nutrients elimination in
  wastewater treatment is not necessary if
  reclaimed water can be blended with normal
  irrigation water.

source GTZ
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FAO irrigation and drainage paper 47 wastewater
treatment and use in agriculture

• Water quality guidelines for maximum crop
  production (example)

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FAO irrigation and drainage paper 47 wastewater
treatment and use in agriculture

• Threshold levels of trace elements for crop
  production (example)