Managing wastewater in the city of the future. Decentralized wastewater and rainwater reclamation and use in Urban Agriculture

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1 Managing wastewater in the city of the future Decentralized wastewater and rainwater reclamation and use in Urban Agriculture

2 Decentralized wastewater and rainwater reclamation and use in Urban Agriculture Session 7. Case studies on sanitation systems for wastewater reuse in urban agriculture. Part 2 Dr. Claudia Pabon Pereira with contributions from Dr. Adriaan Mels, Dr.Katarzyna Kujawa- Roeleveld, Dr. Grietje Zeeman

3 Case studies from the developing world Beijing Lima, Peru The Philippines

4 Beijing a) Capital and political centre of PR China b) 16,808 square kilometres c) Land climate; -20 to +40 d) Precipitation 585 mm; evaporation > 1500 mm per year

5 and a very water scarce city Current water availability is < 300 m 3 per capita per year Severe overexploitation groundwater The shortfall between water supply and demand is estimated to be around 1.8 billion cubic meters by 2010

6 Measures for alleviating water scarcity in Beijing Water saving (410 million cubic meters is planned for 2010) South-to-north water diversion project (1.2 billion cubic meters yearly) Rain water harvest (150 million cubic meters) Wastewater reclamation (640 million cubic meters) source: Wei et al,2005

7 Wastewater reuse planning Current situation of wastewater reclamation systems in urban Beijing (note: this does not include wastewater reuse for agricultural irrigation and industrial reuse: four centralized wastewater treatment plants for reclamation with total treatment capacity of 255,000 m 3 /day km pipeline to redistribute the reclaimed water decentralized wastewater reclamation systems with treatment capacity of 50,000 60,000 m 3 /day source: Water Saving Office,

8 Wastewater reuse planning Figure 1. Wastewater reuse planning for the Beijing central region (source: Jia et al., 2005)

9 Management regulation on the construction of wastewater reclamation facilities in Beijing (1987) In this regulation the Beijing Municipal Government issued that: hotels with construction areas exceeding 20,000 m 2 and all public buildings with construction areas exceeding 30,000 m 2 should build a decentralized reclamation facility. As of 2001 also new residential areas exceeding 50,000 m 2 fall under this regulation

10 Five cases presented (of 9 investigated) Beijing Jiaotong University Beiluchun Residential Area Beijing Normal University Xin Bei Wei Hotel BOBO Garden House Residential Area

11 Technologies and capacities Item Beijing Jiaotong University Beiluchun Residential area Beijing Normal University Xin Bei Wei Hotel BOBO Garden House Residential area Established in Influent source Grey wastewater Mixed wastewater Mixed wastewater Grey wastewater Mixed wastewater Main treatment technology Aerated Contact Activated sludge Ceramic Filter Activated sludge oxidation + disinfection Maximal reclamation capacity (m 3 /day) Contact oxidation + Activated sludge ,200 Average reclamation (m 3 /day) Another 700 m 3 per day are treated and than discharged to the sewer system

12 Beijing Rainbow Hotel (max. 120 m 3 / day) Flocculater adding machine Disinfector Wastewater Reclaimed water Buffer tank Grid Bumper tank Biological contact oxidation reactor Erect sedimentation tank Machine filtration tank Reclaimed water storage tank

13 Technical performance (final water use) Item Beijing Jiaotong University Beiluchun Residential area Beijing Normal University Xin Bei Wei Hotel BOBO Garden House Residential area Use purposes for the reclaimed water (% of total) - toilet flushing 0% yes 2 80% 100% 80% - landscape irrigation 100% yes 20% 0% 15% -street cleaning 0% no 0% 0% 5% - car washing 0% yes 0% 0% 0% - fire water storage 0% yes 0% 0% 0%

14 Financial performance Item Beijing Jiaotong University Beiluchun Beijing Normal University Xin Bei Wei Hotel BOBO Garden House Established in Investment costs for the treatment system (RMB) Operation and maintenance costs (including labor costs) (RMB/m 3 ) Current price of the tap water (RMB/m3) Pay back time (years) * pay back times of 5.1 and 6.3 years at a tap water price of 6.1 RMB / m 3 ** pay back time of 8.0 years at a tap water price of 3.7 RMB /m 3 300,000 1,400,000 3,400, ,000 3,000, * 4.1** 13.8*

15 Some conclusions Both mixed and grey wastewater is reclaimed, various techniques (contact oxidation, activated sludge systems, SBR systems). Systems function well although effluent monitoring is done on voluntary basis and real quality control by an independent party is lacking. Awareness is moderate to high, and users that are aware see it as positive

16 Drivers and barriers for implementation There is a strong financial driver to implement DWRSs, because of the relatively short pay back times, especially for the private sector. Other drivers are related to the regulations and to awareness on water scarcity issues. Universities (3) also use it as educational tool Barriers are high initial investment costs and uncertainty about water charge (for the residential areas)

17 Assessment of the ECOSAN technology in Lima (Peru) and its possible applications The Case of the NGO s CENCA and ALTERNATIVA MSc thesis by Laura López Ramírez MSc Urban Environmental Management

18 PERU OFFICIAL NAME: Republic of Peru CAPITAL: Lima AREA: 1,285,215 km 2 COASTLINE: 2,414 km ESTIMATED 2005 POPULATION: 27,925,628 Residual water Latrine

19 AREA 1 - CENCA A pilot project with 55 dry ecological toilets in two human settlements (slums) at the East of Lima, called Los Topacios of Nievería and Casa Huerta la Campiña of Cajamarquilla

20 Pipe to ventilate the composting chambers AREA 1 - CENCA Shower Washbasin Men urinal

21 No-mix toilet AREA 1 - CENCA Wetlands Composting chambers Fat keeper

22 AREA 2 - ALTERNATIVA A pilot project in Ciudad Nuevo Pachacutec in Ventanilla with the construction of: - 17 water reservoirs of 1500 m public water taps ecological toilets + green gardens + rabbits

23 AREA 2 - ALTERNATIVA Fat Keeper No-mix toilet Wetland Baño Ecológico Sistema de tratamiento Men urinal Sistema de riego Green garden Rabbits

24 Area performance System Maitenance of State Results: area explains performance CENCA ALTERNATIVA

25 Why area matters for system performance CENCA ALTERNATIVA House property Inheritance Donation from government Middle income (Soles/month) NGO involvement after project finished Inhabitants selected sanitation technology Inhabitants designed their toilet Inhabitants paid for the toilet Yes Yes Yes Yes (only the 40%) Tap water Yes No Toilets close to each other Yes No Inhabitants manage the system Users identified with the system Yes Yes No No No No No No

26 Conclusions 1) ECOSAN technology works is affordable, safe and easy to use 2) But big differences in system performance between households 3) Area (involvement) and income explain only 40% of the variation in field performance

27 Philippines MSc thesis Maria DeLange Urine Diversion Dehydration Toilets in Bayawan, Negros Oriental Constructed Wetland in Bayawan, Negros Oriental UDDTs in San Fernando City Fishermens Village in San Fernando City De Lange, 2010

28 Stored urine in San Augustin (SFC, 2010) [1] The scores of SFC are low because the majority of the questionnaires were conducted in Fishermen Village and the LGU is only reusing 10% of the urine and 0% of the faeces f UDDTs Stored Urine in San Agustin in SFC 1 month, fresh, 2 weeks Reuse / City Reuse of urine Reuse of faeces Bayawan San Fernando City Average 81% 29% 55% 56% 11% 34% Barangay Nagyubuyuban in SFC Implemented in schools, Lack of water Non-urban Lack of access to toilet Active monitoring LGU De Lange, 2010

29 UDDTs Advantages Pathogen die-off through dehydration of faeces Pathogen die-off through storage of urine Saving water Low concentration of heavy metals Awareness raising-reestablishing the link beyond the flush and forget Clean environment Health protection Disadvantages Time consuming Needs more space than other toilets urine precipitation and clogging Difficult for children Investment costs De Lange, 2010

30 UDDTs Combined results SFC and Bayawan Do you think the maintenance of the UDDT is dirty? 12% no neutral yes 14% 74% Do you think the maintenance of the UDDT is easy? Do you think the maintenance of the UDDT is time consuming? 41% 15% no neutral yes 44% no neutral yes 58% 26% 16% De Lange, 2010

31 UDDTs The construction and materials of an UDDT cost P For most Filippino families these costs are very high Part of toilet: Paid by Peso Euro Substructure LGU Superstructure beneficiary De Lange, 2010

32 Constructed Wetlands Bayawan City De Lange, 2010

33 Constructed Wetlands Bayawan City-Fishermens Village Gawad Kalinga De Lange, 2010

34 Constructed Wetlands 700 households All the wastewater from toilets, bathrooms and kitchen sinks of 3000 people70% of the inhabitants are satisfied Problems with odour at start-up. Solution to open the valve at night City engineering office is responsible for the operation and maintenance Cheap WWT but costs still high: The total construction costs of the wetland are estimated at P10 million ( ). The annual operation and maintenance costs are estimated at P ( 6557) Low simple maintenance