The Effect of the 2015 Earthquake on the Bacterial Community Compositions in Water in Nepal

Abstract

We conducted a study to examine the effect of seasonal variations and the disruptive effects of the 2015 Nepal earthquake on microbial communities associated with drinking water sources. We first characterized the microbial communities of water samples in two Nepali regions (Kathmandu and Jhapa) to understand the stability of microbial communities in water samples collected in 2014. We analyzed additional water samples from the same sources collected from May to August 2015, allowing the comparison of samples from dry-to-dry season and from dry-to-monsoon seasons. Emphasis was placed on microbes responsible for maintaining the geobiochemical characteristics of water (e.g., ammonia-oxidizing and nitrite-oxidizing bacteria and archaea and sulfate-reducing bacteria) and opportunistic pathogens often found in water (Acinetobacter). When examining samples from Jhapa, we identified that most geobiochemical microbe populations remained similar. When examining samples from Kathmandu, the abundance of microbial genera responsible for maintaining the geobiochemical characteristics of water increased immediately after the earthquake and decreased 8 months later (December 2015). In addition, microbial source tracking was used to monitor human fecal contamination and revealed deteriorated water quality in some specific sampling sites in Kathmandu post-earthquake. This study highlights a disruption of the environmental microbiome after an earthquake and the restoration of these microbial communities as a function of time and sanitation practices.

Investigating the Effects of Atmospheric Pressure Air DBD Plasma on Physio-Chemical and Microbial Parameters of Groundwater

“…[35]. Safe drinking water requires the stability of the microbial community to minimize the release of pathogen [36] and environmental conditions that favor an increased load of pathogens in water also are crucial factors contributing to outbreaks of waterborne diseases [37] [38]. Our results revealed a significant decrease in the colony forming unit (CFU) per 100 mL sample for E. coli as well as total coliform with the increase in plasma treatment time (Table 1).…”

Post-Earthquake Water Quality in Bhaktapur District, Nepal

“…Changes in post-earthquake water quality parameters have widely been studied and changes in chemical and microbial parameters have been reported (Banjara, Paudel, 2017;Uprety et al, 2017). However, in case of Kathmandu valley previous studies and this study demonstrated the microbial contamination of water is quite common before and after the earthquake (Pant, 2010;Pant et al 2016;Uprety et al, 2017). In a country like ours where the use of ground water is prevalent for domestic and drinking purpose microbial contamination of water may have severe effect on human health (Banjara, Paudel, 2017).…”

“…The bacterial population enumerated for E. coli and TC in groundwater and surface water extremely exceeded the NDWQ standards (Table 4). Previous studies also demonstrated that there is wider microbiological contamination of groundwater of Kathmandu valley including Bhaktapur (Pant, 2010;Pant et al 2016;Uprety et al 2017). The E. coli in groundwater was enumerated from 0 to >100 CFU/100 ml of water and for TC it was 0 to >300 CFU/100 ml of water.…”

“…Additionally, soil particles from the soil erosion around the sources due to the earthquake can also make water turbid. Study shows that groundwater microbial genera of Kathmandu increased after the earthquake (Uprety et al 2017). Such microbial organisms like coliform and algae along with metallic ions in dissolved condition contribute turbidity in water (Pant, 2010).…”

Challenges and Opportunities on Urban Water Quality in Mexico City

“…Cities worldwide located in seismic zones have faced changes associated with fractures and variations of soil layers. The natural dynamics of groundwater could be altered in the presence of earthquakes, which has been observed in Santa Barbara County in California (Wood, 2014), the Bam Plains and Baravat in Iran (Malakootian and Nouri, 2010), and in Katmandu, Nepal (Uprety et al, 2017). These changes may be of different magnitudes and may occur at spatially diverse places within the affected areas, which pose complex associated challenges for the city's management authorities.…”