Evaluation of the US EPA-recommended approach to predicting air emissions from pulp and paper industry landfills

There is growing indication that the pulp and paper industry will be requir ed to comply with Clean Air Act (Title V) requirements to estimate emission s of bulk gases and hazardous air pollutants (HAPs) from landfills. One met hods for estimating such emissions involves the use of the Landfill Air Emi ssions Estimation Model (LAEEM), which was developed and calibrated specifi cally for municipal solid waste (MSW) landfills. There is concern about the applicability of LAEEM because the materials placed in industry landfills are considered to be different from those in MSW landfills; as a result emi ssions will likely be lower than model predictions. This study examined the basis of LAEEM and its calibration, and explored al ternative predictive approaches. The authors concluded that LAEEM, when def ined in terms of the default AP-42 factors, does not accurately represent u ncontrolled methane and HAP emissions from industry landfills. It does not account for the attenuating effects of biodegradation and adsorption, nor d oes it account for the potentially slower migration of landfill gas through a fully saturated landfill zone for the oxidation of methane migrating thr ough landfill covers. With adjusted calibration factors that are based on f ield observations, LAEEM may provide more realistic estimates of methane an d HAP emissions from industry landfills.