Quantitative analysis of remedial approaches,costs, and time required to remediate dry cleaner sites

This article presents an analysis of remedial approaches, costs, and time required to remediate dry cleaner sites in the United States based on data compiled by the State Coalition for the Remediation of Dry Cleaners (SCRD). Trends in soil and groundwater remedy selection are identified and discussed. Median costs and the time required to remediate dry cleaner sites are presented. In addition, median costs and the duration of soil and groundwater remediation for the most widely used remedial approaches are reported. The analysis is intended to serve the needs of stakeholders, including responsible parties, consultants, regulators, and litigants, as well as real estate developers, banks, and other holders of portfolios of impacted dry cleaner sites by providing quantitative results useful for planning and transactional analysis. © 2011 Wiley Periodicals, Inc.     

The Scattering Coefficient and Mass Concentration of Smoke from Some Australian Forest Fires

Smoke from large scale fuel reduction fires in Western Australia has been investigated from an aircraft; These fires are typically 10,000-20,000 acres in area with fuel loadings of 3-6 tons/acre. Measurements were made of mass concentration, scattering coefficient and total particulate production in the smoke. The results suggest that the mass concentration (g m^-3) is equal to 0.24 times the scattering coefficient (m^-1). About 1.8% of the fuel appears as particulate matter in the air above the fire.     

Can California coastal managers plan for sea-level rise in a cost-effective way?

This paper examines five representative sites on the California coast to illustrate a cost-effective methodology using tools and data that local decision makers can apply to analyse the economics of sea level rise (SLR) adaptation. We estimate the costs/benefits of selected responses (e.g. no action, nourishment, seawalls) to future flooding and erosion risks exacerbated by SLR. We estimate the economic value of changes to public/private property, recreational and habitat value, and beach related spending/tax revenues. Our findings indicate that the costs of SLR are significant but uneven across communities, and there is no single best strategy for adaptation. For example, Los Angeles's Venice Beach could lose $450 million in tourism revenue by 2100 with a 1.4 m SLR scenario while San Francisco's Ocean Beach would lose $80 million, but the impacts to structures could total nearly $560 million at Ocean Beach compared to $50 million at Venice Beach.     

Changes in the grassland-forest boundary at Ta-Ta-Chia long term ecological research (LTER) site detected by stable isotope ratios of soil organic matter

The carbon isotope analysis [delta13C values] of organic samples can be a useful research in ecological studies because delta13C values are indicative of the plant source. This study investigated the changes in plant communities along the grassland-forest boundary in the alpine forest at Ta-Ta-Chia long term ecological research (LTER) site in central Taiwan using carbon isotope data. The aim of this study was focused on the forest fire affected the change of vegetation community. Four pedons from grassland dominated by Miscanthus transmorrisonensis (pedons 1 and 2), transition zone by Tsuga and Yushania nittakeyamensis (pedon 3), and forest zone by Tsuga and nittakeyamensis (pedon 4) were examined. Soil organic matter (SOM) delta13C values in the upper soil horizon were similar to delta13C values of the overlaying vegetation types. This indicates that the boundary between these plant communities remained the same in the past decades. The delta13C values of the grassland SOM ranged from -19.4 per thousand to -24.1 per thousand, showing decrease with soil depth. This suggests that C4 plants (transmorrisonensis) have replaced C3 plants of Tsuga and nittakeyamensis. The delta13C values of the Tsuga forest area (pedon 4) range from -27.0 per thousand to -23.5 per thousand and showed only slight change with soil depth, implying that C3 plants have remained the major species in the forest.