Chapter 5. Results
5.3. Addition of a further sanitation option
Table 5-3. Environmental indicator values for the pour-flush system
Criterion Raw score Indicator value
efficiency of reduction in VS 65% 3.25
efficiency of removal of N 75% 3.75
efficiency of removal of P 12% 0.6
efficiency of reduction in COD 75% 3.75
energy required for operation less
energy recovered 0 MJ/person/year 5
water required for operation of system less water recovered
4 m3/person/year 4.5 nutrients recovered 0 kg N+P+K/person/year 0 organic material recovered 0 kg DM/person/year 0 5.3.2. Performance of PF on financial and technical criteria
The cost of the pour-flush units in 2014 was approximately R8 500. This was on a par with the cost in eThekwini of UDDTs at the time (Dave Still, Director of Partners in Development, 2015, telephonic communication with author, Pietermaritzburg, 25 January.). Both VIP and UDDT cost were increased proportionally to R7 000 and R8 500 respectively. The emptying costs for UDDTs with on-site burial was estimated at R500 at the same time, and this was adjusted in the MCDA as the annual operations and maintenance costs for UDDTs since the eThekwini Municipality is currently investigating the potential for this service and surveys indicate an overwhelming reluctance on the part of householders to do this themselves (R100/p/y with annual emptying). The pour-flush emptying cost might be less than the VIP cost if a tanker or Vacutug could be used, but for the MCDA the same operations and maintenance was used for both at R100/p/y.
Robustness was considered to be similar to the UDDT. Although the test phase was promising, these systems cannot withstand the abuse that a VIP can and continue to function. They would hopefully require less outside intervention, being more similar to a waterborne system in this respect. Life expectancy was 20 years, the same as the VIP and UDDT and job creation similar to UDDTs, since local people would be trained in construction and emptying would provide further local employment. Local development would be similar to the other two systems. These scores are summarised in Table 5-4.
Table 5-4. Finance and Technology indicator values for the pour-flush system
Criterion Raw score Indicator value
Robustness: ability to withstand abuse, ease of construction, simplicity of design,
robust, challenging construction, simpler technology.
3
Requirement for outside intervention, requirement for monitoring to ensure appropriate disposal of waste
intervention every 5 years 4
Durability: life expectancy of system 20 years 4 Construction cost: materials, labour,
institutional requirements R8 500 R/household 2.24 Cost of O & M: repairs, servicing (e.g.
emptying)
R100/person/year 4.58 Employment: jobs created by
construction and maintenance
5 jobs per 1000 households
2 Local development: promotion of local
business in construction and maintenance
Some local community, some regional
construction and O&M 4
5.3.3. Performance of PF on socio-cultural criteria
While acceptability would not be as high as a fully waterborne system, the pilot project indicated that this system was well received and in most cases preferred to VIPs. While convenience remained an individual perception and not all users preferred the pour-flush toilet to be inside the house, this is possible if users choose this option. No inconvenience was reported with the requirement for maintaining a supply of flush water in the toilet room, so this technology was deemed to be convenient: a fully waterborne system must be the definition of very convenient.
The positive response of users, reported in Still and Louton (2012) suggests that the system could be seen as offering benefits equivalent to fully waterborne sewerage. Excreta are separated from the user by a water seal and users did not find the operation of the system onerous. Hence the rating for the equity indicator was 4. All other indicators were also rated at 4 (see Table 5-5 ) because the implementation would be likely to be similar to other projects of this kind.
Table 5-5 summarises the ratings used in the MCDA for socio-cultural indicators.
Table 5-5. Socio-cultural indicator values for the pour-flush system
Criterion Raw score Indicator value
Acceptability: user perceptions of
fitness for purpose Willingly accepted 4
Convenience: provision of sanitation where users require it, distance from dwelling
Convenient 4
Equity: fulfillment of requirements of all gender groups. equivalence of sanitation provision for different income groups
less advantaged people have equivalent but not same system
4
Legal /institutional: fit with legal requirements, institutional support for construction, O & M
fit with legal requirements full support available at government level, political will is neutral
4
Facility for ongoing hygiene education:
commitment of local authority or national government to fund
fully adequate budget for initial education available and adequate provision for ongoing support hygiene education
4
Participation: facility for user
involvement in planning and execution of project
Users fully involved in planning and execution 4 Food security: contribution of system to
household based food production no contribution 0 Pathogen exposure: requirements of
system for contact with faeces Approximately annual or less often contact with faeces. Full observance of PPE use.
4
5.3.4. Overall performance of PF
The scores for the three systems with the adjusted construction and maintenance costs were 3.14 for VIPs, 2.94 for UDDTs and 3.17 for pour-flush with equal weightings for all criteria. With a heavier weighting (60%) for socio-cultural criteria e.g. in a more challenging political climate, the PF scores 3.30 versus 3.13 for VIPs and 2.81 for UDDTs.