Detection of Indicator Organisms in Drinking Water by Membrane Filtration Method in Open Defaecation Free VDCs of Kaski District, Nepal

Aims: The aim of the project is to detect and enumerate the presence of indicator organisms in drinking water sources of open defaecation free (ODF) village development committees (VDCs) of Kaski district; to compare distribution of Total coliform (TC) and Faecal count (FC) among various water sources.
Study Design: Cross-sectional Study.
Place and Duration of Study: Department of Medical Laboratory Science, School of Health and Allied Sciences, Pokhara University, December 2013 to March, 2014.
Methodology: The study was conducted to detect and enumerate indicator organisms in ODF VDCs of Kaski district, Nepal. 44 water samples were collected from reservoir / distribution tank, tapstand and spring. The bacteriological water quality was analyzed by using membrane filter method to detect the presence and its risk level of fecal contamination to human health in study area. The study mainly focuses on two part of the study; laboratory analysis for water samples and questionnaire survey. Total water samples collected were 44, out of which 32 were from tap, 3 from reservoir tank and 9 from spring. Chlorine disinfection treatment was not done in any VDCs.
Results: All the drinking water samples from Bharatpokhari and Kalika VDCs (100%) were found to be fecally contaminated and the number of total coliforms and fecal coliform per 100ml water were above WHO guidelines for drinking water. None of the water sources from both the VDCs were potable for drinking. Mann-Whitney test was used to compare mean range between samples of two VDCs and mean rank of total coliforms of Bharatpokhari and Kalika VDC were found to be 29.18 and 13.17 and that of Bharatpokhari and Kalika VDCs were found to be 29.80 and 12.89 respectively. Tap water, reservoir/distribution tank and spring water were analyzed to detect indicator organisms and Kruskal Wallis test suggest no significant difference in fecal contamination level among various sources of water was found (p>0.05). The median concentration of fecal coliform of gravity water (spring) in Bharatpokhari was found to be 95 CFU/100ml and that of Kalika is 40 CFU/100 ml. E. coli was detected in every water samples of both the VDCs.
Conclusion: The water bodies used for drinking purpose in Bharatpokhari and Kalika VDC are heavily contaminated with total and fecal coliform bacteria even though those VDCs have been declared ODF. The water bodies used for drinking purpose in Bharatpokhari is found to be more contaminated than Kalika VDC. The distribution of total coliforms and fecal coliforms are same across categories of source of sample. E. coli was isolated from every water sample under study.