Landfill Leachate Migration Through Shallow Unconfined Aquifers


  • David W. Ostendorf,

  • Richard R. Noss,

  • David O. Lederer


We model the transport of a simply reactive contaminant through a landfill and initially pure, underlying, shallow, one-dimensional unconfined aquifer with a plane, sloping bottom under steady hydraulic conditions in the assumed absence of dispersion and downgradient dilution. The user population and a presumedly constant contaminant loading factor determine the pollution input to the groundwater system, and we model the near field response as a single linear reservoir whose output comprises the far field source term at the downgradient edge of the landfill. The far field analysis yields a method of characteristics solution valid in the vicinity of the source location with frame speeds modified by recharge, head loss, bottom slope, and linear adsorption, and concentrations reflecting first-order reaction kinetics. We calibrate and test the near and far field models against conservative chloride and first-order reactive bicarbonate data at the Babylon, New York landfill with accurate and physically plausible results.