Stream Measurements Locate Thermogenic Methane Fluxes in Groundwater Discharge in an Area of Shale-Gas Development
| Autor: | Paul L. Grieve, Victor M. Heilweil, Susan L. Brantley, D. Kip Solomon, Dennis W. Risser, Scott A. Hynek |
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| Rok vydání: | 2015 |
| Předmět: |
Groundwater flow
Water Wells Oil and Gas Industry STREAMS Environment Noble Gases Methane chemistry.chemical_compound Water Supply Environmental monitoring Environmental Chemistry Oil and Gas Fields Groundwater discharge Groundwater Hydrology Carbon Isotopes geography geography.geographical_feature_category General Chemistry Models Theoretical Pennsylvania Hydrocarbons United States Water resources chemistry Water Resources Gases Water Pollutants Chemical Geology Environmental Monitoring Water well |
| Zdroj: | Environmental Science & Technology. 49:4057-4065 |
| ISSN: | 1520-5851 0013-936X |
| DOI: | 10.1021/es503882b |
| Popis: | The environmental impacts of shale-gas development on water resources, including methane migration to shallow groundwater, have been difficult to assess. Monitoring around gas wells is generally limited to domestic water-supply wells, which often are not situated along predominant groundwater flow paths. A new concept is tested here: combining stream hydrocarbon and noble-gas measurements with reach mass-balance modeling to estimate thermogenic methane concentrations and fluxes in groundwater discharging to streams and to constrain methane sources. In the Marcellus Formation shale-gas play of northern Pennsylvania (U.S.A.), we sampled methane in 15 streams as a reconnaissance tool to locate methane-laden groundwater discharge: concentrations up to 69 μg L(-1) were observed, with four streams ≥ 5 μg L(-1). Geochemical analyses of water from one stream with high methane (Sugar Run, Lycoming County) were consistent with Middle Devonian gases. After sampling was completed, we learned of a state regulator investigation of stray-gas migration from a nearby Marcellus Formation gas well. Modeling indicates a groundwater thermogenic methane flux of about 0.5 kg d(-1) discharging into Sugar Run, possibly from this fugitive gas source. Since flow paths often coalesce into gaining streams, stream methane monitoring provides the first watershed-scale method to assess groundwater contamination from shale-gas development. |
| Databáze: | OpenAIRE |
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