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008			230224b |||||||| |||| 00| 0 eng d
040			_aMSU _cMSU _erda
100			_aSUHOGUSOFF, Alexandra V.
245			_aWater quality and risk assessment of dug wells: a case study for a poor community in the city of São Paulo, Brazil
264			_aVerlag _bSpringer _c2013
336			_2rdacontent _atext _btxt
337			_2rdamedia _aunmediated _bn
338			_2rdacarrier _avolume _bnc
440			_aEnvironmental earth sciences _vVolume , number ,
520			_aSparsely populated areas, or peripheral communities commonly lack access to a public water supply and sewerage systems. The inhabitants of these areas must make use of excavated wells to provide their water needs, and cesspits for domestic wastewater disposal. These on-site sanitation systems can release pathogens and nutrients into shallow groundwater. These poor communities urgently require cheap and efficient techniques for the detection of sanitary conditions, in order to prevent contamination of the water resources supplied by dug wells. The sanitary risk assessment methodology, applied in an irregular settlement south of the city of São Paulo, was based on a questionnaire with yes/no questions (risk factors), which allowed the identification of problems related to the well construction and operation, and the presence of potential contamination sources in its vicinity. These risk factors were compared against nitrate and bacterial analysis using the clustering statistical method, to verify the relationship between contamination and certain aspects surveyed in the questionnaire. Questions that were more related to contaminated wells were those concerning the presence of cover and its integrity; gaps between mouth and cover; the surrounding pavement and presence of ground irregularities; infiltration in the well casing; water-suspended materials; and proximity to contamination sources. Contamination models based on variograms allowed to observe that bacterial contamination presented a strong localized component, which was associated frequently with the way residents handled the wells, whereas nitrate contamination was related more to a regional (spatial) component; that is, the distance between wells and cesspits.
650			_asanitary risk assessment method
650			_acluster analysis
650			_abilling reservoir
700			_aHIRATA, Ricardo
700			_aFERRARI, Luiz Carlos K.M
856			_uhttps://doi.org/10.1007/s12665-012-1971-x
942			_2lcc _cJA
999			_c160935 _d160935