3. Using Alternative Sources & Substituting Resources

2 Collecting and storing rainwater for human use from rooftops, land surfaces or rock catchments  as a supplement to piped water supply -household, school & commercial establishment  could be used for toilet flushing, washing and garden spraying  Installation of rainwater harvesting system is mandatory for the construction of buildings in some cities in India (Chennai, Delhi and Mumbai).  Stormwater runoff could be used for artificial recharge Rainwater Harvesting

3 More than one million people in Australia rely on rainwater as their primary source of water supply

4 Rainwater Harvesting in Tokyo

5 Rainwater Harvesting at Changi Airport - Singapore  Rainfall from the runways and the surrounding green areas is diverted to two impounding reservoirs.  The water is used primarily for non-potable functions such fire-fighting drills and toilet flushing.  Such collected and treated water accounts for 28 to 33% of the total water used, resulting in savings of approximately S$ 390,000 per annum.

6  Water reuse - use of treated wastewater* for beneficial purposes such as agricultural, irrigation and industrial cooling.  Water reclamation - treatment or processing of wastewater to make it reusable. Reclaimed water is a treated effluent suitable for an intended water reuse.  Water recycling - normally involves only one use or user and the effluent from the user is captured and redirected back into that use scheme (water recycling is predominantly practiced in industry). * (degree of treatment depends on the intended application) Water Reuse and Recycling (1)

7  Water reuse and recycling provides a unique and viable opportunity to augment traditional water supplies.  Water reuse not only reduces the water demand but also reduces the volume of wastewater to be treated.  The foundation of water reuse is built upon three principles: (1) providing reliable treatment of wastewater to meet water quality requirements for the intended reuse application, (2) protecting public health, and (3) gaining public acceptance. Water Reuse and Recycling (2)

8  Agricultural irrigation  Landscape irrigation  Industrial reuse  Groundwater recharge  Non-potable urban uses  Potable urban uses Categories of Water Reuse

9  Landscape irrigation (garden spraying, public parks and fountains)  Toilet flushing, fire protection, car washing, street cleaning, dust control, air conditioning  Water recycling and reuse in industries (cooling, construction, boiler feed, process water)  Graywater reuse for toilet (without treatment) Water Reuse in Urban Area

10 Range of Available Toilet Types Toilet type (faeces/urine) UD?DescriptionExample Dry mixedNoFaeces + urine mixed, no flush Conventional pit latrine; VIP latrine; composting toilets Dry F/dry U * YesFaeces without, urine without flush UDD toilet (e.g. Separett), waterless urinals Dry F/wet UYesFaeces without, urine with flush (mini flush) Wost-Man, Sweden (UD toilet) Wet mixed (vacuum) NoFaeces + urine mixed, vacuum system (very low flush) Roediger, Germany, vacuum toilet ~ 1 L/flush Wet F/wet UYesFaeces with, urine with flush UD toilet by Dubletten, Sweden or Roediger, Germany. Also called “NoMix Toilet” Wet mixed (gravity) NoFaeces + urine mixed, big flush Conventional flush toilet (WC), ~ 10 L /flush Increasing water use per day UD = with urine diversion * Often wrongly called “ecosan toilet” UDD = Urine diversion dehydrating VIP = Ventilated Improved Pit

11 Daily water consumption estimate for toilets and urinals Toilet type (faeces/urine) Water per defecation event Water per urination event Water use (L/cap/d) Dry mixed000 Dry F/dry U000 Dry F/wet U Wet mixed (vacuum) 115 Wet F/wet U Wet mixed (conventional) Conventional urinalN/A4-6N/A Waterless urinalN/A0 Based on: 1 defecation event per day, 4 urination events per day Increasing water use per day

12 Two types of UD toilets UD waterless toilets –UDD or composting –Not “forgiving” to misuse –Requires shift in thinking for those that are used to waterborne sanitation –May need separate compartment for anal washing –Suitable for slums and areas with unreliable water supply –But not just a technology for the poor (we have it at UNESCO-IHE)! UD water flush toilets –Very similar to conventional water-flush toilets –Very easy to use, “forgiving” to misuse –Urine collected with or without water –Faeces always collected with water –(EAWAG researchers call this the “NoMix toilet”) Urine Faeces

13 Suppliers of waterless urinals Main suppliers in Europe: –Ernst (1) –Keramag (2) –Uridan (3) Others: –In South Africa EcoSmellStop offers a simple and cheap membrane sealing. Contact details are given in the GTZ technical data sheet: b2-urine-diversion-waterless-urinals-2005.pdf –Waterless –Falcon Waterfree USA –Sinaqua Waterless Deutschland –Bluebook Armitage Shanks / Ideal Standard UK –Sphinx HellbrokLocus Waterless no-flush urinals –Water Matrix Waterless No-Flush Urinal –Porcher  Choose carefully - One good indicator is always their reference list and technical knowledge 1 2 3

14 Potential water-savings in different industries Source: Sustainable Water Use in Europe (EEA 2001)

15 Recycled effluent used to water golf courses, Mornington Peninsula, Australia