Saturday, 19 January 2008
Sanitation practice: good and poor
OK, we’re in IYS2008 and we’ve hundreds of millions of people needing adequate sanitation by 31 December 2015 (if, that is, we’re serious about meeting the MDG sanitation target). So what sanitation systems are we likely to be using? In rural areas it’s going to be an on-site system such as single-pit VIP latrines, single-pit pour-flush toilets, eThekwini latrines (urine-diverting alternating twin-vault ventilated improved vault latrines, or UD-VIVs for short), biogas toilets (pour-flush toilets discharging into an anaerobic digester with biogas use for cooking or lighting; usually some animal excreta are added to the digester as well), or a simple EcoSan system (an arborloo or a fossa alterna) − all these need a greywater system (a simple soakaway, or using the greywater to irrigate a ‘greywater garden’). Simplified sewerage (with simple treatment in a facultative pond) has been used in villages in the northeastern Brazilian state of Ceará (details here). You have to work with the beneficiary communities so they end up with a system which they’ll like and can afford, which they’ll operate and maintain properly, and which they’ll regard as their own (and not something foisted on them by government). What about periurban areas? For a start we won’t be using conventional sewerage or multiple-sewer EcoSan systems (both much too expensive). If the population density is low enough, then systems like alternating twin-pit VIPs and PFs and eThekwini latrines (all with a greywater system) would be applicable; but you have to remember that simplified sewerage becomes cheaper above a certain population density (in Natal in northeast Brazil this was only 160 persons per ha). If simplified sewerage is too expensive then (given that on-site systems are more expensive) probably the only solution is SPARC-style community-managed sanitation blocks (SPARC is the Society for the Promotion of Area Resource Centres, an Indian NGO) − read Community-designed, built and managed toilet blocks in Indian cities (Environment & Urbanization, 2003) and watch the video. These sanitation blocks are built, managed and owned by the community; they are only used by the community members, so they are in no sense ‘public’ facilities. Further info. on on-site systems here, simplified sewerage here, communal sanitation here and on good and poor sanitation practice here.