Impact of hotel septic effluent on the Jinfoshan Karst aquifer, SW China


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Publication Date

January 2019


The karst aquifer of Jinfoshan Karst (JFK) in UNESCO’s South China Karst World Heritage Site was investigated. An artificial tracer test, geochemistry, and oxygen and hydrogen isotopes were employed to assess the impacts of effluent from the Jinfoshan Holiday Hotel (JHH), Chongqing, on the karst aquifer and its outlet, Shuifang spring (SFS). Most of the fluorescent dye (uranine) flushed into a JHH toilet was recovered at SFS, suggesting a strong hydraulic connection between JHH and SFS. The waters of SFS were of HCO3–Ca type, whereas the effluent had more complex hydrochemical characteristics. The effluent was characterized by higher mean δD and δ18O values. The slope of the δD–δ18O evaporation line for effluent was significantly lower than that of the local meteoric water line, indicating evaporation. Concentrations of major elements at SFS were below the threshold values of the Chinese Standard for Groundwater Quality. However, hydrogen and oxygen isotopic compositions of SFS waters were influenced by the effluent and mixing with water from diffuse sources within the aquifer. Low values of d-excess at SFS corresponded well to periods of high tourism activity (weekends and holidays), suggesting that declining d-excess probably signifies an increased release of contaminants from the hotel. The contribution of effluent to the discharge of the SFS was ~18%. Because of tourism activities and their production of wastewater, the results of this study may be relevant to other karst environments and World Heritage Sites throughout the world.


Karst, Septic Effluent, Tracer Test, Stable Isotopes, China




Hydrogeology Journal, Vol. 27, no. 1 (2019).