A former landfill site located in Colorado Springs, Colorado was assessed for landfill gas emissions in support of reuse options for the property. The current owners of the landfill and the State of Colorado requested assistance from the EPA Region 8 Office, and the Office of Superfund Remediation and Technology Innovation, Technology Integration and Information Branch to perform a site assessment to search for the presence of any fugitive gas emissions from the site. The focus of this study was to evaluate fugitive emissions of methane and volatile organic compounds at the site in support of the reuse objectives, using a scanning open-path Fourier transform infrared spectrometer, open-path tunable diode laser absorption spectroscopy, and an ultra-violet differential optical absorption spectrometer. The study involved a technique developed through research funded by the EPA's National Risk Management Research Laboratory that uses ground-based optical remote sensing technology, known as optical remote sensing-radial plume mapping. The horizontal radial plume mapping (HRPM) method was used to map surface concentrations, and the Vertical Radial Plume Mapping (VRPM) method was used to measure emissions fluxes downwind of the site.