Economic Assessment of Sanitation Interventions in Vietnam - WSP

Economic Assessment of Sanitation Interventions in Vietnam | Local Benefits of Improved Sanitation and Hygiene4.2.6 WATER USE COSTS IN NON-DOMESTICACTIVITIESIn addition to its household uses (drinking, cleaning, bathingand cooking), water is crucial to other activities in theurban/village environment. In urban areas, this includes itsuse in offices, shops and factories. In rural areas, this includesirrigation for agriculture, livestock farming, fish productionand production in cottage industries.4.3 ACCESS TIMEFamilies without a toilet have to use one of the followingoptions for excretion:(a) using the backyard or a bush in their own plot;(b) using public land, rivers, lakes, and ponds;(c) using a neighbor’s toilet; and(d) using a community (shared) latrine.The average access times (including travel and queueingtime) for each of these options, gathered from the householdsurvey, are:• Round trip to use the bush or backyard: 5 min.• Round trip to use public land: 7 min.• Round trip to use a shared latrine (including waitingtime): 10 min.• Round trip to use a community latrine: 15 min.Some gender differences were found in the use of placesmost commonly accessed by those without household toilet.Women more often went to places with more privacyfor options (b) and (c) while men often use option (a) forurination, and options (b) and (c) for defecation. The averagetime of young children with accompanying parent accessingoff-plot sanitation was 40% of the adult values, asnot all toilet visits required an accompanying parent. Adultsuse these locations on average 4.1 times per person per dayin urban areas, and 3.1 times per day in rural areas. Whilethese data were gathered from relevant questions in the ESIhousehold survey, it was not always easy to get direct andtrue answers on these personal and sensitive issues. The surveyteam combined results from household surveys, fieldobservations and expert opinion in order to tabulate thisinformation. Table 31 presents average savings per householdfrom all surveyed sites who gain access to an on-plottoilet facility.TABLE 31: AVERAGE ANNUAL ACCESS TIME SAVINGS PERHOUSEHOLD (VND, 2008)LocationAverage value of annual savingsUrban 2,487,000Rural 1,686,0004.4 REUSE OF HUMAN EXCRETATable 32 shows the sanitation options used at representativesite R4 (Dan Phuong commune), detailing the number andpercentage of households using composting, urine divertingtoilets (45 households, or 1.5%), toilets and pig pens with abiogas digester (825 households, or 27%). The table showsthat of those with composting toilets and biogas digesters,100% reuse the excreta. Some 5.6% of households reuse thesludge from their septic tanks. Most sludge from the biogasdigesters and composting toilets is reused as fertilizer.TABLE 32: SANITATION COVERAGE, AND % REUSE OFEXCRETA IN SITE R4 (DAN PHUONG COMMUNE)Field siteUNIMPROVEDNumber ofhouseholds%Of whichreuseOD 0 0 0Private pit 95 3.1 21Shared 0 0 0IMPROVEDSimple pit 185 6.1 49UDDT 45 1.5 44Biogas 825 27.0 825Septic tank 1,900 62.3 107There is limited awareness of safe reuse. Most double-vaultcomposting toilets are emptied after a storage time of lessthan 6 months, according to the need for fertilizer andseasonal cropping factors. Therefore, it is necessary to improvethe safety of the composting process through behaviorchange campaigns and other activities. Sludge collectedfrom a biogas digester is also considered a good fertilizer,which is used to grow tropical fruit and vegetables. Somehouseholds practice co-composting of septic tank sludge orbiogas digester sludge with organic waste from the garden,after which it is applied to the crops. This method of sludgehandling significantly enhances reuse safety.www.wsp.org51