Use of tandem circulation wells to measure hydraulic conductivity without groundwater extraction

Conventional methods to measure the hydraulic conductivity of an aquifer on a relatively large scale (10-100 m) require extraction of significant quantities of groundwater. This can be expensive, and otherwise problematic, when investigating a contaminated aquifer. In this study, innovative approaches that make use of tandem circulation wells to measure hydraulic conductivity are proposed. These approaches measure conductivity on a relatively large scale, but do not require extraction of groundwater. Two basic approaches for using circulation wells to measure hydraulic conductivity are presented; one approach is based upon the dipole-flow test method, while the other approach relies on a tracer test to measure the flow of water between two recirculating wells. The approaches are tested in a relatively homogeneous and isotropic artificial aquifer, where the conductivities measured by both approaches are compared to each other and to the previously measured hydraulic conductivity of the aquifer. It was shown that both approaches have the potential to accurately measure horizontal and vertical hydraulic conductivity for a relatively large subsurface volume without the need to pump groundwater to the surface. Future work is recommended to evaluate the ability of these tandem circulation wells to accurately measure hydraulic conductivity when anisotropy and heterogeneity are greater than in the artificial aquifer used for these studies.     

Real-world vehicle emissions: a summary of the Seventeenth Coordinating Research Council On-Road Vehicle Emissions Workshop

The Coordinating Research Council, Inc. (CRC) held its 17th On-Road Vehicle Emissions Workshop in March 2007, where results of the most recent on-road vehicle emissions research were presented. We summarize ongoing work from researchers who are engaged in improving our understanding of the role and contribution of mobile sources to ambient air quality and emission inventories. Participants in the Workshop discussed efforts to improve mobile source emission models, light- and heavy-duty vehicle emissions measurements, on- and off-road emissions measurements, effects of fuels and lubricating oils on emissions, as well as emerging issues and topics for future research.     

Planning for integrated solid waste management at the industrial park level: a case of Tianjin, China

Industrial parks play a significant role in the production and use of goods and services. The proper management of solid waste is a major challenge for industrial parks due to the large quantity of wastes and the variability of waste characteristics from these types of developments. Therefore, integrated solid waste management has become very crucial to the industrial park managers. Such an approach requires industrial park managers to assess the overall use of resources, and to seek waste reduction, reuse and recycling opportunities both at the individual company level and among different tenant companies. The adoption of this method can bring both economic and environmental benefits. This paper introduces the planning efforts of a real case in China. It first presents the basic information on Tianjin Economic Development Area (TEDA), and then introduces its current practices on solid waste management. The main focus of this paper is to describe how to plan an integrated solid waste management system at TEDA. Benefits and challenges are all identified and analyzed. The experiences and methods from this case study should be applied in other industrial parks so as to improve the overall eco-efficiency of the whole industrial park.     

Real-world vehicle emissions: a summary of the Sixteenth Coordinating Research Council On-Road Vehicle Emissions Workshop

The Coordinating Research Council held its 16th workshop in March 2006, with 83 presentations describing the most recent mobile source-related emissions research. In this paper, we summarize the presentations from researchers who are engaged in improving our understanding of the contribution of mobile sources to air quality. Participants in the workshop discussed evaluation of in-use emissions control programs, effects of fuels on emissions, emission models and emission inventories, results from gas- and particle-phase emissions studies from spark-ignition and diesel-powered vehicles, and efforts to improve our capabilities in performing on-board emissions measurements, as well as topics for future research.