Effects of two types of landfills on river water quality and endocrine disruptor concentrations before and after rainfall in a subtropical climate

Abstract

One closed uncontrolled landfill, the Neihu garbage dump, and one active controlled landfill, the Sanzhuku sanitary landfill, were selected for investigation of their leachate characteristics and effects on adjacent river water quality before and after rainfall in northern Taiwan. A total of seven samplings were made during February and June 2007, with four samplings done after individual rainfall events on study sites. Water quality of runoff samples collected from the Sanzhuku sanitary landfill showed less pollution than the water quality of leachates collected from the Neihu garbage dump; however, some water quality levels of leachate samples collected from the Neihu garbage dump were relatively high, such as ammonia nitrogen (NH3-N), orthophosphate (PO43-) and biochemical oxygen demand (BOD5). At the uncontrolled dump, rainfall lead to dilution effects on river water NH3-N and PO43- concentrations, but not other water quality parameters. In contrast, the concentrations of bisphenol A (BPA) and nonylphenol were increased in both types of landfills after rainfall in the present study. Dilution effects of rainfall on most water quality parameters and toxicity tests were observed in the Neihu garbage dump leachates after rainfall, but not for the Sanzhuku Landfill runoff. The highest concentration of BPA measured in this study was 25.8 μg·L-1 in the Sanzhuku sanitary landfill runoff after the heaviest rainfall event, during which 236 mm of rainfall accumulated over four days. The results of this study suggest that both uncontrolled and controlled landfill leachates can be an important potential pollution source of BPA to adjacent water bodies. © 2009, CAWQ.