Dennis P. Campbell
Project title: Landfill Gas Composition Database: A Tool for Predicting Environmental Impacts
Completed in: 1992 | Faculty advisor: David A Kalman
With the increased gas monitoring and testing activities around landfill sites, considerable data have been produced regarding the time, amendments to the Federal Clean Air Act and state-level impacts from industrial emission sources, including landfills. Source data describing landfill gas composition are necessary inputs into models used to predict impacts, but there has been little systematic effort to compile statistically representative descriptions of landfill gas compostion in a mannner that would be readily accessible or interpretable to regulatory agencies or other interested entities. The only US effort to date to compile statistical descriptions of landfill gas composition has been the California Landfill Gas Testing Program. Around the state of Washington and especially around the Puget Sound area, source testing of landfill gas, pre and post combustion, is required by the responsible Air Pollution Control Authority as part of operating permit requirements.
This project aimied to develop a user-friendly database that contained the physical characteristics of a number of landfills, the amounts and types of wastes deposited, and the existing composition data for gas emissions. An important use of this compilation would be to compute the ranges of distributions of concentrations of landfill gas that are available, so any calculations based on composition could include an analysis of variability. The first version of the database has been completed and contains data from 23 landfills around the state. In addition to providing descriptive statistics on LF gas components, the database has been used to explore the hypothesis that landfills can be grouped by their characteristics in a way that predicts gas composition. This would be expected, if the concentration of a particular toxic organic compound or group of toxic organic compounds were a function of either the type of landfill involved, the type of wastes deposited, or a combination of both. Using the databse, it was possible to determine significant correlations between the principal components of landfill gas and between landfill age, the types and volumes of waste composition. In addition, it was possible to conduct comparative analyses on gas emissions from a single landfill or a group of landfills in order to describe the concentrations of various components of landfill gases emitted. By identifying the principal components of landfill gas for a single landfill or a group of landfills with similar characteristics it is possible to assess the potential for their presence in fugitive gas emissions, given the types of wastes deposited.