Before you begin

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Composting Toilet Technology
Chris Salmon GHD, Environment Group Manager NZ
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Composting Toilets Yuck!
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Composting Toilets Yuck!
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Its About Perception

• there is no rule that composting toilets must be
  ugly

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Its About Perception
Photo credit - Reece
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Its About Perception
Photo credit - Reece
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Its About Perception
Photo credit - Reece
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Urine Separation what!!

• It means just what it says
• Its much easier than it sounds

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DCT Resource Benefits

• Save water and
• Recover most nutrients

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Volume Comparison
CONVENTIONAL TOILETS 30 tonnes of
sewage/household/year 95 water
COMPOSTING TOILETS 1 tonne of urine and
compost/household/year 90 urine
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Waste Loads Exported
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Loads from Excreta
Grey Water
WC
Composting toilets can divert all of the
components in black water (brown shaded area) to
agriculture.
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Feasibility Study Report
To download a pdf copy of the executive summary
or the full report go to http//www.ghd.com.au/co
mpostloo
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Outline of Project
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Partners
Smart Water FundDriving innovative water-saving
technologieswww.smartwater.com.au Demaine
Partnership Pty LtdArchitectwww.demaine.net Env
ironment EquipmentDesigning dry toilet
technologywww.rotaloo.com Bensons
PropertyDeveloperwww.bensonsproperty.com.au
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Graphic (section through apartment)
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Trial Reuse Area

• 1.2ha of dry land crops and controls - 350,000
  over 3 years

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Public Acceptance

• Question Would you consider purchasing an
  apartment with a Dry Composting Toilet?

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Public Acceptance

• Question Would you consider paying 5000 extra
  for better water and energy efficiency?

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Health the All Important Issue

• From Stored Urine
• Bacterial lt10-15
• Protozoan infection lt10-7
• Viral lt10-3
• Negligible risk from compost
• Manageable risk for workers
• Manageable risk for householders

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Economics of DCTs

• Backlog/Unsewered Town Areas
• Financial advantage
• Increased if water cost increases
• Inner Urban
• Similar cost to sewerage
• Lower if water cost increases

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Energy Usage

• DTC will not increase energy use

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Conclusions on DCTs

• They save 28 tonnes water per household each year
  

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Detailed Drawing