Quantifying fugitive gas emissions from an oil sands tailings pond with open-path Fourier transform infrared measurements
Abstract. Fugitive emissions from tailings ponds contribute
significantly to facility emissions in the Alberta oil sands, but details on
chemical emission profiles and the temporal and spatial variability of
emissions to the atmosphere are sparse, since flux measurement techniques
applied for compliance monitoring have their limitations. In this study,
open-path Fourier transform infrared spectroscopy was evaluated as a
potential alternative method for quantifying spatially representative fluxes
for various pollutants (methane, ammonia, and alkanes) from a particular
pond, using vertical-flux-gradient and inverse-dispersion methods. Gradient
fluxes of methane averaged 4.3 g m −2  d −1 but were 44 % lower than
nearby eddy covariance measurements, while inverse-dispersion fluxes agreed
to within 30 %. With the gradient fluxes method, significant NH 3 
emission fluxes were observed (0.05 g m −2  d −1 , 42 t yr −1 ), and total alkane fluxes were estimated to be 1.05 g m −2  d −1 (881 t yr −1 ), representing 9.6 % of the facility
emissions.