Churchill K.M.,Weston Solutions |
Link C.,Montana Tech of the University of Montana
IEEE Transactions on Geoscience and Remote Sensing | Year: 2012
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.
Stout S.A.,NewFields Environmental Forensics Practice LLC |
Graan T.P.,Weston Solutions
Environmental Science and Technology | Year: 2010
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.
Deb A.K.,Weston Solutions |
Snyder J.K.,Snyder Environmental Engineering |
Grayman W.M.,W.M. Grayman Consulting Engineer
Journal - American Water Works Association | Year: 2012
The overall reliability of a distribution system depends largely on valve reliability, location, and adequacy of number as well as the frequency of water main failure. Therefore, valve management is an essential aspect of distribution system management. This article details how a computer application, the Strategic Valve Management Model (SVMM), can be used to identify pipe segments associated with pipe breaks, determine valves to isolate the breaks, and perform analyses of valve management alternatives (including present worth costs) to reduce customer service interruptions. Valve management alternatives include the addition of new valves, improvement of valve reliability by exercising valves, or a combination of the two. A set of simple performance indicators was developed to evaluate the performance of valve isolating systems. This article demonstrates applications of the SVMM to hypothetical and actual water distribution systems. © American Water Works Association.
Eldridge K.M.,Weston Solutions
Proceedings of the Air and Waste Management Association's Annual Conference and Exhibition, AWMA | Year: 2012
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).
Woodyard J.P.,Weston Solutions
Proceedings of the American Gas Association, Operating Section | Year: 2010
A presentation covers the PCB and the natural gas industry; PCB issues of concern to the industry since 1978; 2010 advance notice of proposed rulemaking, including use of PCB in natural gas systems, use of PCB in compressed air systems, cleaning and coating old spills, PCB in building products; and TSCA reauthorization and the impact on the PCB regulatory process. This is an abstract of a paper presented at the AGA 2010 Operations Conference (New Orleans, LA 5/13/2010).
Woodyard J.,Weston Solutions
Proceedings of the American Gas Association, Operating Section | Year: 2011
A presentation covers the use of PCB in natural gas systems and its impact; determining the extent of PCB contamination; and keys to a natural gas system delisting strategy. This is an abstract of a paper presented at the AGA National Operations Conference (Nashville, TN 5/27/2011).
Woodyard J.P.,Weston Solutions
Proceedings of the American Gas Association, Operating Section | Year: 2013
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).
Brady S.,Weston Solutions
NPRA Environmental Conference Papers | Year: 2010
EPA test methods are designed to quantify particulate matter (PM) in a sample gas stream either by collecting filterable PM on a filter media or by collecting condensible PM in a series of impingers. Each method has advantages and limitations that need to be considered when developing air permits and compliance strategies or for determining emission reduction credits. A discussion on new measurement methods for fine particulate covers differences that must be addressed to yield proper measurements; traditional test methodologies; sample trains; summaries of method requirements; sample train set-up, operation, and recovery; and checklists for method performance requirements. This is an abstract of a paper presented at the 2010 Environmental Conference (San Antonio, TX 9/20-21/2010).
Middleton B.D.,Sandia National Laboratories |
Mendez C.,Weston Solutions
ASME 2014 Small Modular Reactors Symposium, SMR 2014 | Year: 2014
The existing regulatory structure for nuclear power plants impacts both the design and the operation of the facility . The current structure has been known to be overly conservative in several instances. This overly conservative approach results in operational costs to the facility that decrease the profit margin for nuclear power companies. The current design and build process also results in expensive retrofitting and contributes excess costs to the operations of the facility . The current fleet of nuclear reactors is composed mainly of large light water reactors (LWRs) that can, to some extent, counteract these operational costs by the sheer volume of energy produced. However, the deliberately small size of small modular reactors (SMRs) prevents them from benefitting from this economy of scale. In order to be built and operated economically, SMR vendors must find ways to bring the life cycle costs in line with the economic requirements of nuclear power companies. Sandia National Laboratories has developed a framework that allows vendors and operators to address many of the operational costs during the design and manufacture stages of the SMR life cycle. The framework allows certain operational costs to be addressed in the design stages, thereby decreasing the operational costs, especially those costs associated with staffing and retrofitting. The framework pulls together best practices that have been applied successfully in other industries. Concurrent Engineering (CE) frames the procedural stages, from defining the expectations of the facility deployment, through the identification of regulatory requirements, to the preconceptual, conceptual and detailed design stages. A Project Management Organization is critical to the time management and success of implementing CE. The use of Integrated Safety, Operations, Security, and Safeguards (ISOSS) will lead to achieve a more efficient, cost-effective, and reliable plant. The Balance Model is introduced as a tool to document conflicts between functional areas and identify balancing strategies for conflict resolution in the requirements. Life-Cycle Cost Analysis (LCCA) is proposed as a variable for decision making. Facility Lifecycle Management with Building Information Modeling (BIM) is encouraged to support the Build, Activation, Continued Operations and Decommissioning of the facility . To ensure that the deployment of SMR is effective and cost efficient, the ideal time to implement the framework is now, before SMR designs reach the detailed stage. SMRs hold a lot of potential and this framework can help the nuclear industry realize that potential. Copyright © 2014 by ASME.