A Geochemical and Isotopic Approach to Delineate Landfill Leachates in an RCRA Study

摘要: Under many circumstances during an RCRA investigation, the EPA will not allow intrusive sampling of SWMU (Solid Waste Management Unit, or “waste dump”). This presented difficulties in characterizing waste within a closed landfill identified as located on land owned by Purdue University, 3 kilometers northwest West Lafayette (Indiana) campus because there were few records what was discarded into this public dump its operation from 1958–87. Chemical and isotopic data shallow ground water surface runoff provided realistic means to infer movement contaminants away landfill. Leachate is characterized high concentrations Na+ Cl− (∼ 4mN), sulfate 8 mN), total hardness (Ca+2+ Mg+2∼ 19 alkalinity 12mN). Disposal road salt responsible for NaCl concentrations, while dissolution concrete explains Ca+2, Mg+2, values waters having pC02 only slightly above regional level (10−1.82atm). Deep uncontaminated vicinity have average δ34S value 0.5 per mil (CDT). Since leachate lies between + 10 17 (CDT), are most likely due interred plasterboard consisting primarily gypsum. Tritium activities two wells emplaced 15 meters toe ranged 55 85 TU. Correcting half-lives correlating these historical tritium rainfall measured at Chicago, 3H suggest that travel time interior 20 years.