Microbiological and Hydrochemical Parameters of Deep Wells Used for Drinking Water in Ulaanbaatar, Mongolia

Groundwater is not a nutrient-rich environment for microorganisms to grow and thrive, but it is polluted by many environmental factors. These nutrients can exceed the permissible levels in drinking water and can be a reason for spreading highly infectious diseases in the population. Therefore, there is a need to monitor the quality of water from deep wells in ger areas, to study certain correlations, to prevent people from various infectious diseases, to protect the environment, to use water resources properly, and to provide citizens with accurate information on drinking water. Within the framework of the study, samples were taken from 135 deep wells used for drinking and household purposes in the Bayanzurkh, Bayangol, and Sukhbaatar districts of Ulaanbaatar city. The water quality was analyzed for some hydrochemical (NO3 ) and six main microbiological parameters. Due to microbiological parameters, 42 samples (30.6%) from the surveyed deep wells did not meet the requirements of MNS 0900:2018, the national drinking water standard of Mongolia, and 31 samples (21.9%) exceeded the nitrate ion content described in above the standard. In the Bayangol district, 88% of the surveyed sources found that the number of bacterial contaminants in 100 mL of water exceeded the limit. But in the Sukhbaatar district’s summer camp region which is a relatively low populated area was shown a relatively low level of microbiological contamination and nutrient pollution compared to the permissible level in water samples. According to correlation studies, the nitrate ion concentrations of 12.6% samples over the permissible value (more than 50 mg/L) and high level of bacterial contamination in drinking water, showed a weak correlation.