Producing natural gas from shale deposits generates air pollutant emissions. Increases in conventional air pollution may impact air-quality in shale gas extraction regions. RAND researchers provided a first-order estimate of conventional air pollutant emissions, and the monetary value of the associated environmental and health damages, from the extraction of unconventional shale gas in Pennsylvania.
Estimation of Regional Air-Quality Damages from Marcellus Shale Natural Gas Extraction in Pennsylvania
Published in: Environmental Research Letters, v. 8, no. 1, #014017, Jan–Mar. 2013, p. 1–8
Posted on RAND.org on January 01, 2013
Research Questions
- What is the magnitude of conventional air pollutant emissions generated by Pennsylvania-based shale natural gas extraction activities?
- What are the ranges of potential regional monetized environmental and health damages associated with Pennsylvania-based shale natural gas extraction activities?
- What is relative impact shale gas development might have on regional air quality?
This letter provides a first-order estimate of conventional air pollutant emissions, and the monetary value of the associated environmental and health damages, from the extraction of unconventional shale gas in Pennsylvania. Region-wide estimated damages ranged from $7.2 to $32 million dollars for 2011. The emissions from Pennsylvania shale gas extraction represented only a few percent of total statewide emissions, and the resulting statewide damages were less than those estimated for each of the state's largest coal-based power plants. On the other hand, in counties where activities are concentrated, NOx emissions from all shale gas activities were 20–40 times higher than allowable for a single minor source, despite the fact that individual new gas industry facilities generally fall below the major source threshold for NOx. Most emissions are related to ongoing activities, i.e., gas production and compression, which can be expected to persist beyond initial development and which are largely unrelated to the unconventional nature of the resource. Regulatory agencies and the shale gas industry, in developing regulations and best practices, should consider air emissions from these long-term activities, especially if development occurs in more populated areas of the state where per-ton emissions damages are significantly higher.
Key Findings
- Region-wide estimated environmental and health damages from shale gas activity in Pennsylvania ranged from $7.2 to $32 million dollars in 2011.
- The statewide emissions from Pennsylvania shale gas extraction represented only a few percent of total emissions in the state, and the resulting regional damages were less than those attributable to the largest coal-based power plant in the state.
- In counties where activities are concentrated, NOx emissions from all shale gas activities were 20-40 times higher than allowable for a single minor source, despite the fact that individual new gas industry facilities generally fall below the major source threshold for NOx.
- Two-thirds or more of total emissions are related to ongoing activities, and compressor station activities alone represent 60-75% of all damages.
- A substantial portion of emissions are not specifically attributable to the "unconventional" nature of shale gas and might accompany any large-scale industrial development.
Recommendations
- Regulatory agencies and the shale gas industry, in developing regulations and best practices, should consider air emissions from long-term activities associated with shale gas development, especially if development occurs in more populated areas of the state where net emissions damages are significantly higher.
- Proposals to aggregate industry sources should be carefully considered in terms of the appropriate unit of aggregation (e.g., by company, by geographic region) and any unintended consequences they may create.
- More detailed analyses, including regional data acquisition and consideration of site-specific variability, will be valuable in regions of intense extraction activity and for specific activities and pollutants shown in this analysis to be of most potential concern.
Author Statement
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