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West Chester, PA, United States

Eldridge K.M.,Weston Solutions
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA

In 2010, EPA promulgated amendments to the NESHAP for emissions from reciprocating internal combustion engines. These were later published in 40 Code of Federal Regulations Part 63 Subpart ZZZZ - National Emission Standard for Hazardous Air Pollutants for Stationary Reciprocating Internal Combustion Engines. Depending on engine size and use, these regulations set emission limits and fuel sulfur content limits and require recordkeeping, maintenance, and monitoring. A discussion covers processes based on real situations facing companies that are developing strategies to comply with the MACT Subpart ZZZZ and NSPS Subpart JJJJ and 111 standards for internal combustion engines; system to track the regulatory applicability for each engine; fuel types, i.e., diesel, gasoline, and gaseous; engines impacted by these regulations; issues associated with implementing the requirements of the emission standards; various operational processes that require scrutiny when determining the applicability of Subpart ZZZZ; compliance issues for emergency generators and non-road engine; and compliance documentation. This is an abstract of a paper presented at the 105th AWMA Annual Conference and Exhibition 2012 (San Antonio, TX 6/19-22/2012). Source

Woodyard J.P.,Weston Solutions
Proceedings of the American Gas Association, Operating Section

A presentation covers the 2010 advance notice of proposed rulemaking status and subsequent EPA communications; EPA?s stated concerns on natural gas and PCB; Original changes proposed by EPA concerning natural gas industry; natural gas comments on PCBANRM; outcome of the rulemaking for the natural gas industry; continued use of concrete containing PCB; next steps in rulemaking process; continuing EPA PCB investigations; PCB source "redefinition"; PCB transportation manifesting rule; disposal of PCB remediation waste; and MPCA fact sheet of natural gas systems. This is an abstract of a paper presented at the 2013 AGA Operations Conference (Orlando, FL 5/21-24/2013). Source

Stout S.A.,NewFields Environmental Forensics Practice LLC | Graan T.P.,Weston Solutions
Environmental Science and Technology

Polycyclic aromatic hydrocarbons (PAHs) in urban environments are often derived from point and nonpoint sources, the latter collectively considered as urban background. Quantifying the contributions of point sources and urban background is important for managing and remediating urban sediments. In this work, the sources of PAHs in 350 sediments from a 1.5-mile portion of the Little Menomonee River (Milwaukee, WI) were determined using principal component analysis (PCA), chemical fingerprinting, and positive matrix factorization (PMF), the combination of which mitigates weaknesses of any one method. At issue was quantifying the contributions of a creosote point-source formerly located 3.5 to 5.0 miles upstream versus urban background-derived PAHs in the sediments. In total, creosote and urban background contributed 27 and 73% (±14%) of eight carcinogenic PAHs (CPAHs), respectively, in this part of the River. The concentrations of CPAHs derived from urban background were highest in surface sediments (0?6 in.; 20 ± 17 mg/kg), particularly near major roadway crossings, increased in the downstream direction, and (on average) exceeded the 15 mg/kg regulatory cleanup threshold. Weathered creosote-derived CPAHs were widespread at low concentrations (4.8 ± 8.1 mg/kg) although some discrete sediments, mostly at depths below 6 in., contained elevated CPAHs derived from creosote. This work demonstrates the value of combining multiple techniques in source apportionment studies in urban sediments. It further demonstrates a means to determine the concentration of PAHs attributable to nonpoint sourced background in urban sediments without the need to identify, collect, and analyze (assumedly) "representative" background samples, which may not even exist in heterogeneous urban watersheds. © 2010 American Chemical Society. Source

Wrobel J.,Directorate of Public Works | Gross J.P.,Weston Solutions
Military Engineer

The Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA), or Superfund, remedial action of a 15-acre former salvage yard, fire training area and disposal area at Aberdeen Proving Ground (APG), demonstrates a successful integration of waste reduction and traditional environmental remediation. The site, known as the G-Street Salvage Yard, was on the Superfund National Priorities List for industrial surface and sub-surface soil contamination as well as complications of potential munitions and explosives of concern and chemical warfare material. An important goal of the remediation effort was to minimize the quantity of contaminated media disposed, and to increase the diversion of solid waste as appropriate in a cost-effective manner. Waste reduction techniques include incremental excavation using 12-in lifts where chemical contamination was present at shallow depths, surgical excavation to minimize the number of trees removed, segregation of recyclable metals, a result of the historical use of the site, from excavation waste. Source

Churchill K.M.,Weston Solutions | Link C.,Montana Tech of the University of Montana
IEEE Transactions on Geoscience and Remote Sensing

Unexploded ordnance (UXO) is military ordnance that was fired, dropped, or emplaced but failed to function as intended and thus constitutes an explosive hazard. UXO is a worldwide problem that kills or maims thousands of civilians each year. Magnetic surveys are an efficient means of locating UXO containing ferrous metal when geologic conditions are sufficiently free of magnetic soil and rock. However, discrimination of UXO from non-UXO is complicated by the fact that UXO is often associated with high levels of clutter from ordnance fragmentation. To date, magnetic modeling of UXO has been based on calculations for a simple body of revolution geometry (prolate spheroids). We conducted an investigation to show how numerical modeling, in particular, finite-element modeling of more realistic geometries, compares to prolate spheroid results. Our results show that the calculated dipole moment response for complex models resembling actual UXO is up to 50% higher than the dipole moments for the prolate spheroid model. We also found that altering the shape of a model from a prolate spheroid to a complex shape has a greater effect on dipole moment than maintaining the same shape and altering the volume. Finally, in comparing the surface response from our models to real total field magnetic data, we find that complex models more closely match actual field data than prolate spheroid models. We suggest that modeling and, ultimately, discrimination using more realistic UXO shapes could result in significant improvements in distinguishing UXO from magnetic clutter and geology. © 2011 IEEE. Source

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