An Assessment of Drinking Water Sources in Sagarmatha National Park (Mt Everest Region), Nepal

This study investigated the bacteriological characteristics and physical parameters of drinking water sources in Sagarmatha National Park, Nepal. The park is located in the southeastern part of the Nepali Himalaya and includes the southern slopes of Sagarmatha (Mt Everest). During the 2016 premonsoon dry season, we sampled 29 community drinking water sources and 5 surface-water sources. The physical properties of the samples ranged as follows: temperature 3-17 degrees C, pH 5.41-7.81, conductivity 33.6-175.5 mu S, and total dissolved solids 17.3-94.3 ppm. All of the samples tested met World Health Organization drinking water standards for physical parameters. In terms of fecal contamination, 8 samples contained no CFUs (colony-forming units), conforming to the World Health Organization and Nepali national standards; the remaining 26 samples contained between 1 and 100 CFUs, and this range is rated a low to moderate risk by the World Health Organization but fails to meet the Nepali standards. The data show a positive correlation between bacteria content and temperature, and a weak negative correlation between bacteria content and elevation. Samples from the more populated, lower-elevation (<3500 m) areas had higher levels of Escherichia coli and of coliform bacteria in general. This suggests that the samples from warmer and lower-elevation areas have a higher proportion of surface water in the drinking water, which would account for their elevated bacterial content. This indicates that the deeper groundwater may be uncontaminated and should be the focus of future investigations.