Characterization of leachate from two municipal waste disposal landfills in Puerto Rico and its possible impact on nearby soils and groundwater wells

Municipal solid waste landfills (MSWL) are currently the predominant solid waste disposal practice in Puerto Rico. In these landfills, runoff and rainwater combine with solid waste degradation products to produce leachate. Landfill leachate is rich in organic and inorganic substances, including heavy metal ions.;Although these chemical species represent a public health and environmental hazard, particularly when they reach surface and groundwater systems, no data regarding the type and concentration of heavy metals in leachates from landfills in Puerto Rico was available. At the time this study began, the PREQB did not have data on leachate composition and its impact on nearby soil and groundwater quality for any landfill in PR. Moreover, this agency used data from US landfills for decision-making with regards to landfill problems in Puerto Rico. It was thus a priority to document this information for optimal landfill operation, and to determine potential impact on nearby soil and groundwater wells. The results presented in this dissertation are aimed at addressing this need.;Through this study, the following goals were attained: (1) methods and procedures for sampling and analyzing metals in landfill leachates were designed and implemented; (2) a detailed analysis of selected parameters, using analytic techniques approved by USEPA (U.S. Environmental Protection Agency) were performed; (3) the contribution of these parameters on leachate composition was assessed; (4) the leachate composition of samples obtained at two distinct locations within a specific landfill (one containing metal scraps and the other containing domestic wastes) was compared; (5) the metal composition of leachate from these two landfills was compared with that reported in other studies; and (6) the impact of the Toa Baja landfill leachate on nearby soil and groundwater quality was assessed.