BACTERIAL CONTENT OF DRINKING WATER IN THE SAGARMATHA NATIONAL PARK, NEPAL

The Sagarmatha National Park (SNP) is located in the southeastern part of the Nepali Himalaya Mountains, and encompasses the southern slopes of Sagarmatha (Mt. Everest). Established as a World Natural Heritage Site in 1979, the SNP is the highest altitude protected area in the world. Importantly, the Himalayan Mountains form the main headwaters for major river systems, such as the Ganges, Yangtze and Indus Rivers. Many protected areas, such as the SNP, have promoted tourism to improve their economic conditions. However, the lack of proper resource management strategies has resulted in significant environmental degradation, including the quality of drinking water.

During the 2016 pre-monsoon dry season, we undertook a systematic study of fecal contamination and chemistry of community drinking water sources in the SNP. Our primary goal was to identify coliform bacteria and E. coli in drinking water sources (predominately groundwater-fed springs), which are defined here as the first point of use as a community water source. Physical and biochemical parameters correlated with altitude. Water temperature decreases with increasing altitude whereas pH and conductivity increase with increasing altitude. Total coliform bacteria counts show a significant correlation with temperature and altitude; samples from the more populated, lower altitude areas had higher levels of E. coli and coliform bacteria. However, both E. coli and total coliforms exhibit only a weak negative correlation with increasing conductivity and pH.

Our study clearly indicates the presence of bacterial indicators of fecal pollution. Only four of the 30 samples tested met the Nepali National Drinking Water Quality Standard of 0 colonies per 100 ml sample. However, the majority of the pre-monsoon drinking water sources fall into the “Low Risk” category defined by the World Health Organization with fewer than 10 E. coli colonies per 100 ml sample. Only 9 of the 30 drinking water sources tested can be categorized as “Moderate Risk” category (10 -100 E. coli colonies per 100 ml) and no “High Risk” samples were found. Additional focus will be put on testing post-monsoon (high flow) community drinking water sources for fecal pollution and determining the ratio of ground water to surface water in the drinking water sources.