Drinking Water Quality in the Sagarmatha National Park, Nepal

Abstract

In 2014 we began the first systematic study of water quality, specifically fecal contamination of drinking water in the Khumbu Valley, Sagarmatha National Park (SNP, Mt. Everest region), Nepal. Our goal was to identify coliform bacteria and E. coli in drinking water and groundwater-fed springs to generate a data set that will function as a base for potable water supplies and further monitoring. Sampling occurred in May (pre-monsoon summer) and early November (post-monsoon early winter) 2014. Sample sites were selected based on proximity to villages and primary use as a drinking water source. Overall, the data presented a predictable correlation between fecal contamination and both elevation and increasing population/tourist traffic. Drinking water within the study area met current World Health Organization drinking water standards for the physical properties of temperature (2.8°C - 13°C), pH (5.27 - 7.24), conductivity (14.5 - 133 mS) and TDS (7.24 - 65.5 ppm). Samples from the more populated, lower altitude areas had higher levels of E. coli. Samples collected and analyzed in May (pre-monsoon summer) had a higher level of E. coli and coliform bacteria than samples collected in November (post-monsoon early winter) suggesting a seasonal dependence overlaid on the population signature. Surface water typically had higher E. coli values than groundwater-fed springs. Temperature, total dissolved solids and conductivity generally decreased with increasing elevation, whereas pH increased with increasing elevation. There appears to be significant presence of fecal contamination of water sources due to a combination of tourism, elevation and seasons.