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Annapolis, MD, United States

Castro M.S.,University of Maryland Center for Environmental science | Sherwell J.,Power Plant Research Program
Environmental Science and Technology | Year: 2015

Coal-fired power plants in the United States are required to reduce their emissions of mercury (Hg) into the atmosphere to lower the exposure of Hg to humans. The effectiveness of power-plant emission controls on the atmospheric concentrations of Hg in the United States is largely unknown because there are few long-term high-quality atmospheric Hg data sets. Here, we present the atmospheric concentrations of Hg and sulfur dioxide (SO2) measured from 2006 to 2015 at a relatively pristine location in western Maryland that is several (>50 km) kilometers downwind of power plants in Ohio, Pennsylvania, and West Virginia. Annual average atmospheric concentrations of gaseous oxidized mercury (GOM), SO2, fine particulate mercury (PBM2.5), and gaseous elemental mercury (GEM) declined by 75%, 75%, 43%, and 13%, respectively, and were strongly correlated with power-plant Hg emissions from the upwind states. These results provide compelling evidence that reductions in Hg emissions from power plants in the United States had their intended impact to reduce regional Hg pollution. © 2015 American Chemical Society. Source


Sherwell J.,Power Plant Research Program
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2014

Studies by the DOE have shown that the US offshore wind resource is very large with a potential of 900,000 Mw and that its utilization could contribute significantly to electricity supply while reducing reliance on fossil fuels. As with all emerging technologies, offshore wind power will need policy consistency at the federal level. There is a lot of technical and permitting support offered by the federal government but financial incentives seem to be lacking, especially in the light of current climate change mitigation proposals. The current business climate has not been conducive to development in the offshore realm but policies at both the state and federal level are being crafted to enable projects, but challenges remain. Offshore windpower enablement and the challenging issues to the offshore wind power industry are discussed. This is an abstract of a paper presented at the AWMA's 107th Annual Conference & Exhibition (Long Beach, CA 6/24-27/2014). Source


Redling K.,University of Pittsburgh | Elliott E.,University of Pittsburgh | Bain D.,University of Pittsburgh | Sherwell J.,Power Plant Research Program
Biogeochemistry | Year: 2013

While epidemiologists have long acknowledged that automobile emissions create corridors of increased NOx concentrations near highways, the influence of these emissions on dry nitrogen (N) deposition and effects on surrounding ecosystems are not well-characterized. This study used stable isotopes in plant tissue and dry N deposition to examine the extent of N deposition from automobile emissions along a roadside transect spanning 400 m perpendicular to a moderately trafficked highway (33,000 vehicles per day). Passive samplers were deployed monthly for four months at six stations to collect dry deposition of nitric acid (HNO3) and nitrogen dioxide (NO2), analyzed for concentration and natural abundance isotopic composition (δ15N). Agrostis perennans (bentgrass) and Panicum virgatum (switchgrass) were deployed as biomonitors to examine relative sources of N to plant tissue. Both NO2 flux and δ15N-NO2 values were significantly higher close to the road indicating a high proportion of automobile-sourced N is deposited near-road. Further, this near-road deposition occurred primarily as NO2 prior to oxidation to HNO3, as HNO3 fluxes were an order of magnitude lower than NO2 fluxes and were highest midway through the transect. Plant tissue δ15N values were higher near the road, signifying the influence of automobile emissions on plant tissue composition. Importantly, N flux near the road was four times higher than background N flux measured at the nearest regional dry deposition monitoring locations. We extrapolated these results to demonstrate that the observed spatial patterns of concentrated N deposition impact our understanding of regional N deposition to watersheds when applied to a metropolitan area. © 2013 Springer Science+Business Media Dordrecht. Source


Faustini C.J.,Environmental Resources Management Inc. | Keating R.L.,Environmental Resources Management Inc. | Gray S.T.,Power Plant Research Program
Air and Waste Management Association - Power Plant Air Pollutant Control "MEGA" Symposium 2012 | Year: 2012

In response to Maryland's 2006 Healthy Air Act (HAA) legislation, Mirant Mid-Atlantic (now GenOn Energy) modified its Morgantown Generating Station to incorporate flue gas desulfurization (FGD). The HAA, a multi-pollutant air pollution control program, requires substantial reductions in emissions of NOx, SO2, and mercury from coal-fired generating units at power plants in Maryland. The Power Plant Research Program (PPRP) within Maryland DNR is charged with coordinating the State's environmental review of proposed new power plants or plant modifications. Wet FGD systems require large quantities of water to operate. PPRP conducted a thorough alternatives analysis of potential water sources (including ground water, surface water from the tidal portion of the Potomac River, which would require desalination technology, and reclaimed wastewater) to meet the project needs in a way that conserves water resources in accordance with State policy. This paper will describe PPRP's alternatives analysis and Mirant's selected approach. Source


Mountain P.D.,Annapolis flyer cab | Sherwell J.,Power Plant Research Program | Walters G.,Annapolis flyer cab
Air and Waste Management Association - Power Plant Air Pollutant Control "MEGA" Symposium 2012 | Year: 2012

In response to Maryland's 2006 Healthy Air Act (HAA) legislation, Constellation Energy modified its Brandon Shores power plant to incorporate flue gas desulfurization (FGD). The HAA requires substantial reductions in emissions of NOx, SO2, and mercury from coal-fired generating units in Maryland. The Power Plant Research Program (PPRP) within Maryland Department of Natural Resources is charged with coordinating the State's environmental review of proposed new power plants or plant modifications. Wet FGD systems require large quantities of water to operate. Over the past 20 years, PPRP has evaluated the use of treated wastewater to provide water for several proposed power plant projects. For Brandon Shores, PPRP worked with Constellation and the Maryland Department of the Environment (MDE) to develop license conditions to allow for safe use of this water in the FGD system. This paper will discuss the technical requirements and some of the operating experience of treated wastewater reuse in Maryland. Source

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