Groundwater methane in a potential coal seam gas extraction region
Study region: This study investigates dissolved methane distribution in groundwater from the Richmond River Catchment (New South Wales, Australia) before proposed coal seam gas (CSG, or coal bed methane) development. Study focus: Unconventional gas exploration has rapidly expanded in recent years. H...
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| Format: | Article |
| Language: | English |
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Elsevier
2015-09-01
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| Series: | Journal of Hydrology: Regional Studies |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2214581815000853 |
| _version_ | 1818061943438573568 |
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| author | Marnie L. Atkins Isaac R. Santos Damien T. Maher |
| author_facet | Marnie L. Atkins Isaac R. Santos Damien T. Maher |
| author_sort | Marnie L. Atkins |
| collection | DOAJ |
| description | Study region: This study investigates dissolved methane distribution in groundwater from the Richmond River Catchment (New South Wales, Australia) before proposed coal seam gas (CSG, or coal bed methane) development.
Study focus: Unconventional gas exploration has rapidly expanded in recent years. However, the impact of these operations on groundwater systems is poorly understood. A total of 91 groundwater samples were analyzed from 6 geological units. Our observations act as regional baseline research prior to CSG extraction and may assist with long term impact assessment.
New hydrological insights for the region: Methane was found in all geological units ranging between 0.26 and 4427 μg L−1 (median 10.68 μg L−1). Median methane concentrations were highest in chloride-type groundwater (13.26 μg L−1, n = 58) while bicarbonate-type groundwater had lower concentrations (3.71 μg L−1). Groundwater from alluvial sediments had significantly higher median methane concentrations (91.46 μg L−1) than groundwater from both the basalt aquifers (0.7 μg L−1) and bedrock aquifers (4.63 μg L−1); indicating geology was a major driver of methane distribution. Methane carbon stable isotope ratios ranged from –90.9‰ to –29.5‰, suggesting a biogenic origin with some methane oxidation. No significant correlations were observed between methane concentrations and redox indicators (nitrate, manganese, iron and sulphate) except between iron and methane in the Lismore Basalt (r2 = 0.66, p < 0.001), implying redox conditions were not the main predictor of methane distribution. |
| first_indexed | 2024-12-10T13:56:21Z |
| format | Article |
| id | doaj.art-8e2c90f0e19a49798c091c3179994527 |
| institution | Directory Open Access Journal |
| issn | 2214-5818 |
| language | English |
| last_indexed | 2024-12-10T13:56:21Z |
| publishDate | 2015-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Hydrology: Regional Studies |
| spelling | doaj.art-8e2c90f0e19a49798c091c31799945272022-12-22T01:45:57ZengElsevierJournal of Hydrology: Regional Studies2214-58182015-09-014PB45247110.1016/j.ejrh.2015.06.022Groundwater methane in a potential coal seam gas extraction regionMarnie L. Atkins0Isaac R. Santos1Damien T. Maher2School of Environmental Science and Management, Southern Cross University, Lismore, New South Wales 2480, AustraliaSchool of Environmental Science and Management, Southern Cross University, Lismore, New South Wales 2480, AustraliaSchool of Environmental Science and Management, Southern Cross University, Lismore, New South Wales 2480, AustraliaStudy region: This study investigates dissolved methane distribution in groundwater from the Richmond River Catchment (New South Wales, Australia) before proposed coal seam gas (CSG, or coal bed methane) development. Study focus: Unconventional gas exploration has rapidly expanded in recent years. However, the impact of these operations on groundwater systems is poorly understood. A total of 91 groundwater samples were analyzed from 6 geological units. Our observations act as regional baseline research prior to CSG extraction and may assist with long term impact assessment. New hydrological insights for the region: Methane was found in all geological units ranging between 0.26 and 4427 μg L−1 (median 10.68 μg L−1). Median methane concentrations were highest in chloride-type groundwater (13.26 μg L−1, n = 58) while bicarbonate-type groundwater had lower concentrations (3.71 μg L−1). Groundwater from alluvial sediments had significantly higher median methane concentrations (91.46 μg L−1) than groundwater from both the basalt aquifers (0.7 μg L−1) and bedrock aquifers (4.63 μg L−1); indicating geology was a major driver of methane distribution. Methane carbon stable isotope ratios ranged from –90.9‰ to –29.5‰, suggesting a biogenic origin with some methane oxidation. No significant correlations were observed between methane concentrations and redox indicators (nitrate, manganese, iron and sulphate) except between iron and methane in the Lismore Basalt (r2 = 0.66, p < 0.001), implying redox conditions were not the main predictor of methane distribution.http://www.sciencedirect.com/science/article/pii/S2214581815000853Stable isotopesAquiferBaseline researchGeologyCatchmentHydrochemistryCoal bed methaneUnconventional gas |
| spellingShingle | Marnie L. Atkins Isaac R. Santos Damien T. Maher Groundwater methane in a potential coal seam gas extraction region Journal of Hydrology: Regional Studies Stable isotopes Aquifer Baseline research Geology Catchment Hydrochemistry Coal bed methane Unconventional gas |
| title | Groundwater methane in a potential coal seam gas extraction region |
| title_full | Groundwater methane in a potential coal seam gas extraction region |
| title_fullStr | Groundwater methane in a potential coal seam gas extraction region |
| title_full_unstemmed | Groundwater methane in a potential coal seam gas extraction region |
| title_short | Groundwater methane in a potential coal seam gas extraction region |
| title_sort | groundwater methane in a potential coal seam gas extraction region |
| topic | Stable isotopes Aquifer Baseline research Geology Catchment Hydrochemistry Coal bed methane Unconventional gas |
| url | http://www.sciencedirect.com/science/article/pii/S2214581815000853 |
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