scholarly journals Hydrogeochemistry Studies in the Oil Sands Region to Investigate the Role of Terrain Connectivity in Nitrogen Critical Loads

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2204
Author(s):  
John J. Gibson ◽  
Sandra Jean Birks ◽  
Michael C. Moncur ◽  
Amy Vallarino ◽  
Caren Kusel ◽  
...  
Keyword(s):  
Critical Loads ◽  
Oil Sands ◽  
Field Work ◽  
Secondary Importance ◽  
Athabasca Oil Sands Region ◽  
Poor Fen ◽  
Physical Measurements ◽  
Isotopic Characterization ◽  
Terrain Units ◽  
Nitrogen Exchange

Hydrology and geochemistry studies were conducted in the Athabasca Oil Sands region to better understand the water and nitrogen cycles at two selected sites in order to assess the potential for nitrogen transport between adjacent terrain units. A bog—poor fen—upland system was instrumented near Mariana Lakes (ML) (55.899° N, 112.090° W) and a rich fen—upland system was instrumented at JPH (57.122° N, 111.444° W), 100 km south and 45 km north of Fort McMurray, Alberta respectively. LiDAR surveys were initially conducted to delineate the watershed boundaries and topography and to select a range of specific locations for the installation of water table wells and groundwater piezometers. Field work, which included a range of physical measurements as well as water sampling for geochemical and isotopic characterization, was carried out mainly during the thaw seasons of 2011 to 2015. From analysis of the runoff response and nitrogen species abundances we estimate that nitrogen exchange between the wetlands and adjacent terrain units ranged between 2.2 and −3.1 kg/ha/year for rich fens, 0.6 to −1.1 kg/ha/year for poor fens, and between 0.6 and −2.5 kg/ha/year for bogs, predominantly via surface pathways and in the form of dissolved nitrate. A significant storage of dissolved ammonium (and also dissolved organic nitrogen) was found within the pore water of the bog-fen complex at Mariana Lakes, which we attribute to decomposition, although it is likely immobile under current hydrologic conditions, as suggested by tritium distributions. In comparison with the experimental loads of between 5 and 25 kg/ha/year, the potential nitrogen exchange with adjacent terrain units is expected to have only a minor or negligible influence, and is therefore of secondary importance for defining critical loads across the regional landscape. Climate change and development impacts may lead to significant mobilization of nitrogen storages, although more research is required to quantify the potential effects on local ecosystems.

scholarly journals Using carbon-14 and carbon-13 measurements for source attribution of atmospheric methane in the Athabasca Oil Sands Region

2021 ◽  
Author(s):  
Regina Gonzalez Moguel ◽  
Felix Vogel ◽  
Sébastien Ars ◽  
Hinrich Schaefer ◽  
Jocelyn Turnbull ◽  
...  
Keyword(s):  
Oil Sands ◽  
Surface Mining ◽  
Atmospheric Methane ◽  
Source Attribution ◽  
Athabasca Oil Sands ◽  
Ch4 Emissions ◽  
Athabasca Oil Sands Region ◽  
Carbon 14 ◽  
Isotopic Characterization ◽  
Tailings Ponds

Abstract. The rapidly expanding and energy intensive production from the Canadian oil sands, one of the largest oil reserves globally, accounts for almost 12 % of Canada’s greenhouse gas emissions according to inventories. Developing approaches for evaluating reported methane (CH4) emission is crucial for developing effective mitigation policies, but only one study has characterized CH4 sources in the Athabasca Oil Sands Region (AOSR). We tested the use of 14C and 13C carbon isotope measurements in ambient CH4 from the AOSR to estimate source contributions from key regional CH4 sources: (1) tailings ponds, (2) surface mines and processing facilities, and (3) wetlands. The isotopic signatures of ambient CH4 indicate that the CH4 enrichments measured at the site were mainly influenced by fossil CH4 emissions from surface mining and processing facilities (53 ± 18 %), followed by fossil CH4 emissions from tailings ponds (36 ± 18 %), and to a lesser extent by modern CH4 emissions from wetlands (10 < 1 %). Our results confirm the importance of tailings ponds in regional CH4 emissions and show that this method can successfully separate wetland CH4 emissions. In the future, the isotopic characterization of CH4 sources, and measurements from different seasons and wind directions are needed to provide a better source attribution in the AOSR.

scholarly journals The Effects of Plume Episodes on PAC Profiles in the Athabasca Oil Sands Region

2021 ◽  
pp. 117014
Author(s):  
Narumol Jariyasopit ◽  
Tom Harner ◽  
Cecilia Shin ◽  
Richard Park
Keyword(s):  
Oil Sands ◽  
Athabasca Oil Sands ◽  
Athabasca Oil Sands Region

scholarly journals Quantification of methane sources in the Athabasca Oil Sands Region of Alberta by aircraft mass balance

2018 ◽  
Vol 18 (10) ◽  
pp. 7361-7378 ◽  
Author(s):  
Sabour Baray ◽  
Andrea Darlington ◽  
Mark Gordon ◽  
Katherine L. Hayden ◽  
Amy Leithead ◽  
...  
Keyword(s):  
Mass Balance ◽  
Oil Sands ◽  
Surface Mining ◽  
Open Pit ◽  
Emission Rates ◽  
Athabasca Oil Sands ◽  
Emissions Inventory ◽  
Athabasca Oil Sands Region ◽  
Major Surface ◽  
Tailings Ponds

Abstract. Aircraft-based measurements of methane (CH4) and other air pollutants in the Athabasca Oil Sands Region (AOSR) were made during a summer intensive field campaign between 13 August and 7 September 2013 in support of the Joint Canada–Alberta Implementation Plan for Oil Sands Monitoring. Chemical signatures were used to identify CH4 sources from tailings ponds (BTEX VOCs), open pit surface mines (NOy and rBC) and elevated plumes from bitumen upgrading facilities (SO2 and NOy). Emission rates of CH4 were determined for the five primary surface mining facilities in the region using two mass-balance methods. Emission rates from source categories within each facility were estimated when plumes from the sources were spatially separable. Tailings ponds accounted for 45 % of total CH4 emissions measured from the major surface mining facilities in the region, while emissions from operations in the open pit mines accounted for ∼ 50 %. The average open pit surface mining emission rates ranged from 1.2 to 2.8 t of CH4 h−1 for different facilities in the AOSR. Amongst the 19 tailings ponds, Mildred Lake Settling Basin, the oldest pond in the region, was found to be responsible for the majority of tailings ponds emissions of CH4 (> 70 %). The sum of measured emission rates of CH4 from the five major facilities, 19.2 ± 1.1 t CH4 h−1, was similar to a single mass-balance determination of CH4 from all major sources in the AOSR determined from a single flight downwind of the facilities, 23.7 ± 3.7 t CH4 h−1. The measured hourly CH4 emission rate from all facilities in the AOSR is 48 ± 8 % higher than that extracted for 2013 from the Canadian Greenhouse Gas Reporting Program, a legislated facility-reported emissions inventory, converted to hourly units. The measured emissions correspond to an emissions rate of 0.17 ± 0.01 Tg CH4 yr−1 if the emissions are assumed as temporally constant, which is an uncertain assumption. The emission rates reported here are relevant for the summer season. In the future, effort should be devoted to measurements in different seasons to further our understanding of the seasonal parameters impacting fugitive emissions of CH4 and to allow for better estimates of annual emissions and year-to-year variability.

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