Summary of Studies for

Richard Statom, Fiessinger Scholarship Winner 2001

(Report - summer 2003)

Mr. Statom's current research is centered on the changes that occur in municipal solid waste (MSW) landfill leachate over time.  In the first phase of the research, leachate chemistry data from a lined landfill cell in Florida was investigated and the changes that occurred over 12½ years were analyzed.  The results of this phase of the research have been accepted for publication (with minor revisions) in the peer-reviewed journal Environmental Geology.

The temporal analysis showed that the leachate exhibited an overall declining trend in major ion chemistry over time.  Decreasing or stable trends were noted for all parameters examined except for calcium, total inorganic carbon, iron, and manganese.  Iron and manganese concentrations increased only after closure, which suggests that closure activities may have contributed to the increased levels of these parameters.  Concentrations of other metals in the leachate were generally below detection levels.

Although overall trends could be discerned from the data, there were wide variations in concentrations between individual sampling events that were probably connected to the amount of rainfall at the landfill.  Some of these short-term variations could look like increasing trends to state and federal regulators if not viewed in the context of the overall data set.  For landfill operators, this suggests that it is important to be aware of the overall long-term trends in leachate chemistry, not just the last few sampling events. 

The next phase of Mr. Statom's research is ongoing and involves modeling the chloride concentrations (a major component of leachate) in the subject landfill cell.  Using a computer model to recreate the overall declining trend of chlorides, which was documented in a report given at the 2002 Annual meeting of the Geological Society of America in Denver, Colorado, has been successful.  A modified version of the computer model will be used to recreate the individual concentrations instead of the overall trends.  If successful, the model has the potential to be used to predict future chloride concentrations in the leachate.  A model that can successfully predict the concentration of a major component of leachate has considerable potential as a tool for landfill operators.

These two lines of investigation are part of his overall goal of to provide landfill operators and researchers with long-term data on the changes in MSW landfill leachate quality over time and potential tools (such as a computer models) for better understanding and predicting these changes.