In Ghana, the prevalence of onsite sanitation is more than 85%. This means that when the receptacles containing the faecal sludge are full they have to be collected and treated before discharging into the environment. Unfortunately, there are very few treatment plants available in the country and fecal sludge is mostly dumped into water bodies, drains, trenches, farms, bushes, and other unauthorized places.

1. EminentPanelConference,Accra,August7th -9th,2020
COST-BENEFIT ANALYSIS OF FAECAL SLUDGE
MANAGEMENT IN GHANA
Esi Awuaha, Ahmed Issahakua, Martha Osei-Marfob, Sampson Oduro
Kwartenga, Micheal Addo Aziatsia and Copenhagen Consensus.
a(Dept. of Civil Engineering, KNUST)
b(Dept. of Water and Sanitation, UCC)

2. Faecal Sludge characteristics
• Human excreta production 130-450g of excreta daily and 1.4L of urine everyday
• Major source of pathogens viruses, bacteria, protozoans and helminths
• Source of nutrients –Nitrogen, Phosphorous etc
• Source of Energy in the form of organic carbon
• The pathogens calls for treatment before its application and use
• Calling for proper handling and management of excreta leading to now what we
will call sanitation
Sanitation is basically the protection of a community from
diseases associated with poor waste management practices
and the improvement in the overall environmental quality.

3. Background information
Accra(years back)
Nungua Farms Dumpsite
Tamale
Cape coast

4. Volta Region
Takoradi
Koforidua
Background information
Dompoase - Kumasi

5. Problems Associated with Poor Faecal Sludge Management
• About 85% of onsite sanitation
toilet technologies in Ghana.
• This leads to improper dumping of the waste
leading to rapid transmission of diseases.
• 88% of diarrhea diseases in Accra due to Sanitation
• 41million cases of Diarrhea in 2017 nation wide
• The diseases due to poor sanitation including improper
disposal of faecal sludge is 290million dollars.
• 1.6% of GDP

6. DESCRIPTION OF FAECAL SLUDGE TREATMENT TECHNOLOGIES
2. Comprehensive treatment
plant
3. Faecal sludge treatment biogas to electricity plant at
Lavender Hill in Accra
4. Sludge biomass to electricity
1. Waste Stabilization ponds

7. COMPREHENSIVE FAECAL SLUDGE
TREATMENT PLANTS
(Intervention 1)

8. Comprehensive Waste treatment plant at Lavender Hill

9. Comprehensive treatment plants would cost 1,349m cedis with
CAPEX costs of 642m cedis
Total Costs = 1,349m cedis
Capex costs = 642m cedis
• 9.1m cedis fixed cost per plant
• 82,000 cedis per m3 daily treatment capacity
• 280m3 average daily treatment req per plant
• 3.2m cedis fixed cost for 2km access road per plant
Opex and enforcement costs = 101m cedis in year 1
• 12% of capex (based on study from Dakar, Senegal)
• 24% of capex for those near coast
• 40% increased enforcement capacity
Estimated lifespan of each plant
• Ideal scenario: 15 years if properly maintained
• Realistic scenario: Only 50% of plants are still operating after
10 years. This accounts for:
• Technical, financial and other maintenance issues that
prevent continued operations
• Lack of compliance with sanitation laws and
indiscriminate dumping of sludge
-
100,000,000
200,000,000
300,000,000
400,000,000
500,000,000
600,000,000
700,000,000
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
GHS
Costs of comprehensive treatment plants
Capex Costs Opex Costs

10. Intervention will avoid 329 deaths and 1.9m cases of diarrhea in
the first year
Benefits = 3962m cedis
Health benefits
• Assume faecal sludge treatment can maximally reduce diarrheal
disease by 30%
• Estimation inferred from meta-analyses and a study on pathogen
transmission in Accra though evidence is limited
• Leads to 329 deaths and 1.9 m cases of diarrhea avoided initially,
decreasing in line with plant failure
• This effect size is tempered by reported regional estimates of
i) sewer coverage and ii) open defecation
• FST cannot influence pathogens that are already transmitted via
sewer or that are defecated direct into the environment
• Largest effect size is in Ashanti (26%), lowest effect size is Upper East
(10%)
Other benefits
• Does NOT include other potential benefits from cleaner
environment including tourism, lack of smell,
improved biodiversity
-
100,000,000
200,000,000
300,000,000
400,000,000
500,000,000
600,000,000
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
Benefits
Initial decrease due
to plant failure
Later increase due
increase in value of
life years in line
with GDP

11. BCR of comprehensive treatment plants is 2.9
Intervention Benefits
(millions cedis)
Costs
(millions cedis)
BCR
Comprehensive treatment
plants across Ghana
3962 1349 2.9

12. Comprehensive FST targeted areas
• The areas targeted for this intervention are Tema Metropolis, Cape Coast metropolis, Effutu
Municipal, Adansi North, Kumasi Metropolis, Sunyani Municipal, New Juaben Municipal, Tamale
Metropolis, Sekondi/Takoradi Metropolis, Bolgatanga, Wa, Ho Municipal, Bunkprugo-Yunyoo,
Nkwanta South, Sawla-Tuna-Kalba, Asunafo North, Sefwi Wiaso and Techiman Municipal. All the
sixteen regions in Ghana were considered.
(18 areas)
• Cumulatively, a total of about 6.8 million people will be reached by
the intervention.

13. ENERGY/RESOURCE RECOVERY SYSTEMS
(Intervention 2)

14. Biogas to Energy (Electricity)
Costs = 1579m cedis
Capex costs = 784m cedis
• 7.8m cedis fixed cost per plant
• 27,000 cedis per m3 daily treatment capacity
• 200m3 average daily treatment req per plant
• 3.2m cedis fixed cost for 2km access road per plant
Opex and enforcement costs = 115m cedis p.a. in year 1
• 12% of capex (based on study from Dakar, Senegal)
• 24% of capex for those near coast
• 40% increase in enforcement capacity
Estimated lifespan of each plant
• Ideal scenario: 15 years if properly maintained
• Realistic scenario: Only 50% of plants are still
operating after 10 years.
Benefits = 7485m cedis
Health benefits
• Assume faecal sludge treatment can maximally reduce
diarrheal disease by 30%
• Leads to 591 deaths and 3.8m cases of diarrhea avoided initially,
decreasing at the same rate as plant failure
Resource recovery benefits
• 48,000 kWh produced per year
• 1.3 cedis per kWh economic benefit (based on Ghanaian
study)
• Very minor contribution, <1% of benefits
Other benefits
• Does NOT include other potential benefits from cleaner
environment including tourism, lack of smell, improved
biodiversity

15. Sludge to Energy (Electricity)
Costs = 1395m cedis
Capex costs = 688m cedis
• 7.8m cedis fixed cost per plant
• 18,000 cedis per m3 daily treatment capacity
• 200m3 average daily treatment req per plant
• 3.2m cedis fixed cost for 2km access road per plant
Opex costs = 102m cedis in year 1
• 12% of capex (based on study from Dakar, Senegal)
• 24% of capex for those near coast
• 40% increase in enforcement capacity
Estimated lifespan of each plant
• Ideal scenario: 15 years if properly maintained
• Realistic scenario: Only 50% of plants are still
operating after 10 years.
Benefits = 7451 m cedis
Health benefits
• Assume faecal sludge treatment can maximally reduce
diarrheal disease by 30%
• Leads to 591 deaths and 3.8 m cases of diarrhea avoided
initially, decreasing at the same rate as plant failure
Resource recovery benefits
• Very minor contribution, <1% of benefits
Other benefits
• Does NOT include other potential benefits from cleaner
environment including tourism, lack of smell, improved
biodiversity

16. BCR of Energy/Resource Recovery Systems
Intervention Benefits
(millions cedis)
Costs
(millions cedis)
BCR
Biogas to Energy 7485m 1579m 4.7
Sludge to Energy 7451m 1395m 5.3

17. Sludge to Electricity Target areas
• The areas targeted for this intervention are Tema Metropolis, Cape coast metropolis, Effutu
Municipal, Adansi North, Kumasi Metropolis, Sunyani Municipal, New Juaben Municipal, Tamale
Metropolis, Sekondi/Takoradi Metropolis, Bolgatanga, Wa, Ho Municipal, Bunkprugo-Yunyoo,
Nkwanta South, Sawla-Tuna-Kalba, Asunafo North, Sefwi Wiaso, Techiman Municipal, Ada west,
Ashaiman Municipal, Agona west Municipal, Ajumako-Enyan-Essiam, Assin Central, Twifo-Heman-
Lower Denkyira, Asokore Mampong, Atwima Kwanwoma, Mampong Municipal, Sekyere Central,
Berekum Municipal, Dormaa Central Municipal, Jaman North, Birim North, Birim Central
Municipal, Fanteakwa, Karaga, Nanumba North, Sagnerigu Municipal, Yendi, Ahanta West, Nzema
East, Wassa Amenfi West, Bawku, Garu Tempane, Talensi, Jirapa, Lawra, Sissala East Akatsi south,
ketu south North Tongu, Chereponi Mamprusi East,Biakoye, Krachi East, Bole Gonja Central Asutifi
South, Tano North, Aowin, Bia west, Sefwi Bibiani-Ahwiaso Bekwai, Atebubu Amantin, Kintampo
North Municipal, Pru and Nkoranza South. All the sixteen regions in Ghana were considered.
(64 areas)
• Cumulatively, a total of about 14 million people would be reached by
the intervention in the country.

18. STABILIZATION PONDS
(Intervention 3)

19. Stabilization ponds across Ghana would cost 926m cedi with
capex costs of 436m cedis
Costs = 926m cedis
Capex costs = 436m cedis
• 2.3m cedis fixed cost per pond
• 34,000 cedis per m3 daily treatment capacity
• 120m3 average daily treatment req per pond
• 3.2m cedis fixed cost for 2km access road per pond
Opex and enforcement costs = 59m cedis in year 1
• 12% of capex (based on study from Dakar, Senegal)
• 24% of capex for those near coast
• 40% increase in enforcement capacity
Estimated lifespan of each pond
• Ideal scenario: 15 years if properly maintained
• Realistic scenario: Only 75% of ponds are still operating after 5
years. This accounts for:
• Technical, financial and other maintenance issues that prevent
continued operations
• Lack of compliance with sanitation laws and indiscriminate
dumping of sludge
-
50,000,000
100,000,000
150,000,000
200,000,000
250,000,000
300,000,000
350,000,000
400,000,000
450,000,000
500,000,000
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
GHS
Costs of stabilization ponds
Capex Costs Opex Costs

20. -
100,000,000
200,000,000
300,000,000
400,000,000
500,000,000
600,000,000
700,000,000
Benefits
Intervention will avoid 263 deaths and 1.9m cases of diarrhea in
the first year
Benefits = 4113m cedis
Health benefits
• Assume faecal sludge treatment can maximally reduce diarrheal
disease by 30%
• Estimation inferred from meta-analyses and a study on pathogen
transmission in Accra though evidence is limited
• Leads to 263 deaths and 1.9m cases of diarrhea avoided initially,
decreasing in line with plant failure
• This effect size is tempered by reported regional estimates of i)
sewer coverage and ii) open defecation
• FST cannot influence pathogens that are already transmitted via sewer
or that are defecated direct into the environment
• Largest effect size is in Ashanti (26%), lowest effect size is Upper East
(10%)
Other benefits
• Does NOT include other potential benefits from cleaner
environment including tourism, lack of smell, improved biodiversity
Benefits increase as value
of mortality risk
reduction increases with
GDP growth

21. Targeted areas for Waste stabilization ponds
• Ada West, Ashiaman Municipal, Agona West Municipal, Ajumako-Eryan-Essiam, Assin
Central, Twifo-Heman-Lower Denkyira, Asokore Mampon, Atwoma Kwanwoma,
Mampong Municipal, Sekyere central, Berekum Municipal, Dormaa central Municipal,
Jaman North, Birim North, Birim Municipal, Fanteakwa, Karaga, Nanumba north,
Sagnerigu Municipal, Yendi, Ahanta West, Nzema East, Wassa Amenfi West, Bawku, Garu
Tempane, Talensi, Jirapa, Lawra, Sissala East Akatsi south, ketu south North Tongu,
Chereponi Mamprusi East,Biakoye, Krachi East, Bole Gonja Central Asutifi South, Tano
North, Aowin, Bia west, Sefwi Bibiani-Ahwiaso Bekwai, Atebubu Amantin, Kintampo
North Municipal, Pru and Nkoranza South. All the sixteen regions in Ghana were
considered.
(46 areas)
• Cumulatively, a total of about 7.1 million people would be reached by
the intervention in the country.

22. BCR of stabilization pond is 4.4 across all Ghana
Intervention Benefits
(millions cedis)
Costs
(millions cedis)
BCR
Stabilization ponds across all
Ghana
4113m 926m 4.4

23. BCR Summary of Faecal sludge interventions
Intervention Benefits
(millions
cedis)
Costs
(millions
cedis)
BCR
Comprehensive
treatment plants
3962m 1349m 2.9
Biogas to energy
plants
7485m 1579m 4.7
Sludge to energy
plants
7451m 1395m 5.3
Stabilization ponds 4113m 926m 4.4
Notes
• All interventions pass benefit-cost
test but overall evidence base is
limited
• Evidence on diarrhea benefits is
very limited, 30% reduction as a
maximum benefit seems
reasonable but no studies to date
confirm this with high certainty
• Evidence of failure rates across
time are also limited -> affects long
term costs and benefits

24. Intervention Areas
1. Comprehensive treatment plants, BCR = 2.9
- Urban district capitals across Ghana
- Targeting 18 sites across Ghana with 6.8m population served
2. Resource recovery plants (sludge to electricity, biogas to electricity), BCR = 4.7
to 5.3
- Can be placed in peri-urban or urban sites
- Targeting 64 sites across Ghana with 14 million population served
3. Stabilization ponds, BCR = 4.4
- Peri-urban sites across Ghana with enough land availability
- Targeting 46 sites across Ghana with 7.1 population served

25. Conclusion
• Irrespective of the intervention used, the returns are positive

26. Sensitivity Analysis
BCR for
Comprehensive
BCR for
Stabilization
Pond
BCR for
Biogas to
energy
BCR for
Sludge to
Energy
Central 2.9 4.4 4.7 5.3
No failure 3.4 4.8 5.5 6.2
Failure is twice
as fast and large 2.5 3.7 4.0 4.5
Diarrhea
impact +50% 4.4 6.7 7.1 8.0
Diarrhea
impact -50% 1.5 2.2 2.4 2.7
Costs +25% 2.3 3.6 3.8 4.3
Costs -25% 3.9 5.9 6.3 7.1

27. Recommendations
• The Environmental Impact Assessment should be considered before implementation.
• More detailed site specific studies to ascertain more precise benefits to costs before project
implementation.
• Plants when installed should be managed by Public Private Partnership and paid based on
performance contract.
• The Assemblies and regulatory bodies should ensure that this is done.
• Plan for Land acquisition for treatment plants should be done as a matter of urgency
• More research studies on current treatment facilities is needed to assess the real economic
benefits

28. Thank You