Groundwater Quality Concerns for Ulaanbaatar, Mongolia
Abstract
Ulaanbaatar, the capital of Mongolia, is completely dependent on the Tuul River aquifer for its water supply. Groundwater quality is threatened by industrial development in the city as well as population growth, particularly due to rapid unplanned growth in "Ger districts" which rely on pit latrines for waste disposal. To ascertain the impact of these developments on groundwater quality, sampling of the aquifer was conducted in the fall of 2019. Sampling was focused on determining the presence of (1) nitrate, which would result from the unlined pit latrines, and (2) volatile organic compounds (VOCs), which would result from industrial and commercial activity. As was previously shown by Batsaikhan et al. (2018) nitrate contamination in the Ger districts is considerable. The current study shows that this contamination is spreading and may eventually impact the city water supply wells. The current study also found that two carcinogenic VOCs, trichloroethene (TCE) and tetrachloroethene (PCE), were present in the aquifer at levels that exceeded U.S. Environmental Protection Agency safe drinking water standards. Downgradient of the area where these VOCs were present are city water supply wells, and in fact, both TCE and PCE were measured in one of the city water supply wells. No fuel hydrocarbons were found in the groundwater, presumably because the aquifer is aerobic thereby promoting natural biodegradation. These results indicate that the city water supply is threatened by both inorganic and organic groundwater contamination, and preventative strategies should be implemented to protect the aquifer from further contamination. Strategies might include development of water and wastewater infrastructure to serve the Ger districts, systematic spatio-temporal monitoring of groundwater quality, and regulation of industrial and commercial hazardous material storage and waste disposal practices.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMH050...08B
- Keywords:
-
- 1807 Climate impacts;
- HYDROLOGY;
- 1831 Groundwater quality;
- HYDROLOGY;
- 1832 Groundwater transport;
- HYDROLOGY;
- 1847 Modeling;
- HYDROLOGY