The purpose of this paper is to develop a methodology to evaluate the feasibility of using landfill gas (LFG) as a liquefied natural gas (LNG) fuel source for heavy-duty refuse trucks operating on landfills. Using LFG as a vehicle fuel can make the landfills more self-sustaining, reduce their dependence on fossil fuels, and reduce emissions and greenhouse gases. Acrion Technologies Inc. in association with Mack Trucks Inc. developed a technology to generate LNG from LFG using the CO2 WASH process. A successful application of this process was performed at the Eco Complex in Burlington County, PA. During this application two LNG refuse trucks were operated for 600 hr each using LNG produced from gases from the landfill. The methodology developed in this paper can evaluate the feasibility of three LFG options: doing nothing, electricity generation, and producing LNG to fuel refuse trucks. The methodology involved the modeling of several components: LFG generation, energy recovery processes, fleet operations, economic feasibility, and decision-making. The economic feasibility considers factors such as capital, maintenance, operational, and fuel costs, emissions and tax benefits, and the sale of products such as surplus LNG and food-grade carbon dioxide (CO2). Texas was used as a case study. The 96 landfills in Texas were prioritized and 17 landfills were identified that showed potential for converting LFG to LNG for use as a refuse truck fuel. The methodology was applied to a pilot landfill in El Paso, TX. The analysis showed that converting LFG to LNG to fuel refuse trucks proved to be the most feasible option and that the methodology can be applied for any landfill that considers this option.

Groundwater samples were collected from eight wells in remote Antelope Creek valley, Idaho. Seven out of eight locations showed that groundwater 222 Rn concentrations were much greater than 11 Bq/L (300 pCi/L), a maximum contaminant level (MCL) proposed by United States Environmental Protection Agency (USEPA).Rock and soil samples collected near the sampling wells revealed that 238 U contents were between 0.55 to 6.41 ppm. Minerals collected from different regions of the country with similar 238 U contents also showed high concentrations of 222 Rn in the groundwater. An interpretation technique using a Geographic Information System (GIS) software with available information also indicated a clear correlation between the rock types and 222 Rn concentrations in the groundwater.Several cancer rates near the study area reported to be higher than national average. Many factors can be affecting 222 Rn in the groundwater, what may these factors be in the study area and if the 222 Rn concentration is a contributing factor to certain high cancer rates in the area remain to be subjects of interest.