Study on the influence of cattle keeping on the bacteriological quality of domestic well water

Abstract

Wells are the main sources of water supply in Indian villages and towns as elsewhere in any of the rural areas of the developing tropical countries. The shallow, open, dug wells are liable to contamination from the surrounding sources by various means. Faecal contamination of water is considered as one of the major causes of health hazards resulting in innumerable diseases among people throughout the world. Therefore, the bacteriological analysis of water is aimed at the detection and enumeration of indicators of faecal pollution. The movement of animal excreta into surface and ground water is considered a major factor contributing to the bacteriological pollution of available water in many regions.

In order to assess the influence of cattle keeping on the bacteriological quality of domestic well water in Mannuthy area, the present study was undertaken. Forty wells from households randomly selected, with and without cattle keeping, for the study spreading over for a period of six months covering the summer and south-west monsoon during 1981. Water samples were collected aseptically, once in each season. They were bacteriologically analysed for SPC, MPN of coliforms and the detection and enumeration of E.coli. FS and C1 perfringens.

Bacterial counts in water from all wells far exceeded the standards recommended for open, shallow wells. Although an apparently higher SPC in water from households with cattle keeping than from those without was observed, it was not statistically significant. The seasonal variation in the counts showed a hundred-fold increase in the case of SPC during monsoon than summer. But the similar increase in the MPN was negligible. The indicator bacteria, especially E.Coli and C1.perfringens showed a significant reduction during monsoon.

The sanitary survey of the wells conducted with the help of a ready made performa revealed that none of the wells could be considered satisfactory either in construction or maintenance. The SPC and FS counts were found to have a positive correlation with the depth of wells. The SPC was positively correlated with the type of latrine also. The MPN of coliform and the depth of lining and distance of cattle shed from well were negatively correlated; so also a negative correlation was observed in the case of FS count and the distance between latrine and well.

The various characteristics of wells, cattle keeping and latrines were found to have a significant correlation with the SPC and MPN of coliforms. When these of wells and latrines were alone considered, they showed significant correlation only with FS count. But it was observed that the characteristics of wells and latrines alone could explain for the considerable variations in the SPC and MPN than those of cattle keeping, as a source of pollution.

It is concluded that the type of construction of well do not have any direct bearing on the bacteriological quality of well water except in the case of Cl. perfringens counts. Cattle keeping has also no significant influence on the bacteriological quality of domestic well water in Mannuthy area though all wells under study showed evidence of recent or past faecal contamination.