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Financial incentives for excreta and wastewater useAshley Murray – IWMI-Ghana2nd Ghana Water Forum, Accra 19-21 October 2010
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Water for a food-secure world
FINANCIAL INCENTIVES FOR EXCRETA AND WASTEWATER USEAshley Murray – IWMI-Ghana2nd Ghana Water Forum, Accra 19-21 October 2010
Water for a food-secure worldWater for a food-secure world
Reuse…why bother?Environmental benefits• resource conservation• protect surface waterSocial benefits• decrease public health threat of indiscriminate
discharge
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Financial benefits• help pay for adequate treatment of
*WW/**FS• attract private sector – decrease public
management burden• decrease WW/FS treatment costs
Photo credits: A. Murray
*WW – wastewater**FS – fecal sludge
Water for a food-secure worldWater for a food-secure world 3
“[w]e need to transform the way we look at wastewater, recognizing it as a resource rather than a problem, and manage it accordingly,” (pp 133-134, World Water
Development Report 3 March2009)
TREATMENT PLANTS IN GHANA:• 70 urban treatment plants & ~10 operate effectively • Absence of money for operation and management is a common cause of failure
• Inadequate billing systems• Low household ability and willingness to pay
(Murray and Drechsel 2010)
Photo credits: A. Murray and IWMI
Water for a food-secure worldWater for a food-secure world
DESIGN FOR REUSE: harvesting the value of effluent and nutrients for sustaining the operation of sanitation facilities – IWMI-Ghana & WRCGoals: 1. Improve long-term integrity of WW/FSTPs
in Ghana; 2. Influence shift in status-quo WW/FSTP design
Approach: Demonstrate the benefits of reuse for helping to pay for the costs of WW/FS treatment
Research activities: 1. Cost-benefit analyses and/or demonstration of incorporating aquaculture, irrigation, biogas recovery, land application of FS (dried, composted); 2. Value-chain construction; 3. Implementation & operation protocols; 4. Business model development
Accra, Kumasi, Sekondi-Takoradi
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*WW – wastewater**FSTP– fecal sludge treatment plant
Water for a food-secure worldWater for a food-secure world 5
HYPOTHETICAL CASE: LEGON WASTE STABILIZATION SYSTEM MATURATION PONDSAssumptions:total flow = 6400 m3/d (~81,500 p.e.)maturation pond = 2.1 ha (5-day retention time)stocking density = 3 fish/m2
total fish = 256,000Photo credit: A. Murray
Water for a food-secure worldWater for a food-secure world
WW-fed aquaculture financial-flow model
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fish
Waste Stabilization Ponds (WSP)(e.g. government operated)
privately operated fish farm (in maturation pond(s))
FISH$$
consumers
$
$ for WSP *O&M
operating expenses:e.g. fingerlings, labor
*O&M – operation & managementSource: Created by A. Murray for the purpose of this presentation
Water for a food-secure worldWater for a food-secure world
Hypothetical Legon WSP-aquaculture: cost-revenue forecast
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Unit Cost (GH¢) Total Cost (GH¢)
Start-up Costs
Aquaculture equipment (barrels, boots, nets, scale, water quality testing)
1000 1000
Direct Operating Costs
Catfish fingerlings 0.20 each 17,000
Fish feed 0
Site manager/inspector 150/mo 900
Water/fish quality analysis 75 600
Profits
Gross Profit (catfish sales, 75% survival) 3/kg fish 192,000
Net Profit per 6-month cultivation period 172,500
Legon *WSP 6-mo operating cost: GH¢ 86,000
*WSP - Waste Stabilization PondsSource: Created by A. Murray for the purpose of this presentation
Water for a food-secure worldWater for a food-secure world
Wastewater irrigation financial-flow model
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cultivated farmland
Wastewater treatment plant (WWTP)(e.g. WSP, anaerobic/aerobic reactors )
veg.$$
consumers
$
farmers/labor, inputs
$ for *WSP **O&M
POTENTIAL MANAGEMENT MODELSSingle entity owns and operates WWTP and farmland
orWWTP proprietor leases land to private operator
* WSP – waste stabilization pond*O&M – operation & management
Source: Created by A. Murray for the purpose of this presentation
Water for a food-secure worldWater for a food-secure world
WW irrigation: case studyWASTEWATER
TREATMENT SYSTEM
• ~95 m3/d• in disrepair –
little/no treatment
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FARMLAND
• currently rain-fed – no access to *WW
• ~8 ha mixed maize & vegetables
Photo credit: A. Murray Photo credit: A. Murray Photo credit: IWMI
*WW – wastewaterCase study was performed at the Presbyterian Boys Secondary School, Legon, Ghana
Water for a food-secure worldWater for a food-secure world
WW irrigation: case study
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Jan JanFeb
Mar Mar
AprApr
MayJun Jun Jul
AugAug
SepOct Oct
NovDec
Dec0
500
1000
1500
2000
2500
3000
3500
Irrigation Req.(m3/ 10-d.ha) Rainfall (m3/10-d.ha)
wastewater flow (m3/10 day
Temporal irrigation demand vs. Wastewater flow
Profit-max irrigation: ~31,000 m3/yr vs. Wastewater generation: ~35,000 m3/yr
*WW – wastewaterSource: Murray and Buckley (2010)
Water for a food-secure worldWater for a food-secure world
WW irrigation case study: cost-revenue forecast
Unit Cost (GH¢) Total Cost (GH¢)
Direct Operating Costs – Farming
farm labor (16 per year) 100/mo 19,200
inputs (seeds, fertilizer, pesticide)a 400/ha 3200
Profits
Gross Profit (crop sales @ profit-max crop mix)b 44,000
Estimated WWTP O&M costc 5/p.e. 10,500
Net Profit 11,100aBased on input costs reported by farmers in Manya Krobo, Eastern Region (Cofie et al. 2010)bBased on optimization model results using FAO’s CropWat data (adapted from Murray and Ray 2010)cAssumes aerated sequencing batch reactor (current technology) (Von Sperling 2005)
*WW – wastewaterSource: Created by A. Murray for the purpose of this presentation
Water for a food-secure worldWater for a food-secure world
Policy and programming relevance• National Environmental Sanitation
Strategy and Action Plan (NESSAP) 2010– Decentralized Treatment, Reuse and Recovery (DETRR)
Facilities– Private sector engagement
• fully franchised management of all government-built treatment plants by 2015
• Large-scale sanitation projects underway– Accra Sewage Improvement Project (AfDB –
Africa Development Bank)– Urban Environmental Sanitation Project (WB –
World Bank)
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Water for a food-secure worldWater for a food-secure world
So, next time… Don’t think of wastewater.
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Water for a food-secure worldWater for a food-secure world
Relevant publications• Murray, A. and P. Drechsel (2011). "Why do some wastewater treatment facilities
work when the majority fail?" Waterlines (in press).• Murray, A. (2010). Demanding reuse at wastewater treatment plants: A case of the
private sector helping to pay for sanitation. World Water Week, Stockholm. Available at: www.worldwaterweek.org/.../Ashley_Murray_WWW_2010_pres.pdf.
• Murray, A. and C. Buckley (2010). Designing Reuse-Oriented Sanitation Infrastructure: The Design for Service Planning Approach. Wastewater Irrigation and Health: Assessing and Mitigating Risk in Low-Income Countries. P. Drechsel, M. Redwood, L. Rachsid-Sally and A. Bahri. London, Earthscan, IDRC, IWMI: 303.
• Murray, A. and I. Ray (2010). "Back-End Users: The Unrecognized Stakeholders in Demand-Driven Sanitation." Journal of Planning Education and Research 30(1): 94-102.
• Murray, A. and I. Ray (2010). "Wastewater for agriculture: A reuse-oriented planning model and its application in peri-urban China." Water Research 44(5): 1667-1679.
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