Assessing the Level of Fecal Contamination on Soil and Water From Pit Latrine and Septic Tank Latrine System - The Case of Khulna City, Bangladesh

In Bangladesh, the population is growing rapidly in big cities. For this, the congested habitat and slum areas are increasing as well. In and around Khulna city area, there is uprising the number of slum areas where major number of toilet system is not properly improved.  This trend has evolved an issue of fecal waste management in proper way. As unmanaged fecal sludge has serious effect on the outer environment. Therefore, taking this issue under consideration, this study has been performed to assess the fecal and other pathogenic contamination on water and soil from the practice of major two types of toilet system (septic tank latrine and pit latrine). In this study, the samples (both water and soil) which were collected from near to septic tank toilet were denoted as Type-A and the samples (both water and soil) which were taken from near to pit latrine were denoted as Type-B. The microbial analysis of water samples and pathogenic assessment for soil transmitted helminthes (STHs) were performed by membrane filtration technique and sucrose floatation technique respectively. Some major Physicochemical analysis were also conducted for both soil and water samples. It was revealed that 70% tube wells situated near to pit latrines were contaminated by disease-causing Escherichia coli, whereas, only 20% water samples of Type-A were found which were contaminated by E. coli. Moreover, it was observed that almost all of the tube well water samples (80%) of Type-A found no risk for consumption in terms of microbial risk category. In contrast, the majority (70%) of tube well water of Type-B consumption was demonstrated risky. Furthermore, the soil sample analyses revealed that both type of soil contains STHs. But, the determined intestinal parasites were in high amount in soil samples collected from the nearby sites of pit latrines than the soil samples collected from the nearby location of septic tank latrines. Along with, the physicochemical analysis showed that the soil samples collected from near to septic tank latrines were mildly alkaline, slightly saline and moderately organic in character. On the contrary, this characteristic were moderately alkaline, moderately saline and highly organic for those soil samples which were taken from the places situated near to pit latrines. The findings of this study will help to provide a strong evidence of contamination from latrine system on the two major environmental components (water and soil).

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