Evaluating regulatory issues and emission control equipment for air toxics applications

This article describes regulatory issues and emission control equipment for air toxics applications. A brief history of air quality legislation is provided, illustrating the difficulty government has had in implementing air quality statutes; this has contributed to the complexity of air quality regulations. Evaluation methodologies are described for three different emission control technologies: thermal oxidation, catalytic oxidation, and adsorption. Brief case histories are provided that describe the pitfalls and benefits associated with each technology. The benefits of integrating health risk assessment into an air quality program are also discussed.     

Application of the pressure-state-response framework to perceptions reporting of the state of the New Zealand environment

The Pressure-State-Response framework for environmental reporting was used as a basis to develop a long-term study of people's perceptions of the state of the New Zealand environment. A postal survey of 2000 people, randomly drawn from the New Zealand electoral roll was used to gather data--an effective response rate of 48% was achieved. A range of different resource sectors was examined. We report on New Zealand's air, native animals and plants, and marine fisheries, as well as New Zealand compared to other developed countries. Respondents generally considered that in terms of pressures, states and responses, New Zealand was performing better than other developed countries and that for the resources examined here overall performance was in the adequate to good range, except for marine fisheries. The survey appears to be a useful tool for linking perceptions data into State of the Environment reporting. It also helps identify policy issues where perceptions do not match other scientific evidence or management initiatives. Such findings can be important for the successful implementation of policy measures.     

Effect of Cage Design on Growth of Transplanted Asian Clams: Implications for Assessing Bivalve Responses in Streams

This study was designed to determine whether survivorship and growth of Asian clams (Corbicula fluminea [Müller]) differed significantly between two types of field enclosures. Enclosures were either flexible mesh bags or rigid cages (hereto after referred as bioboxes) designed to homogenize substrate among study sites and accommodate Asian clam feeding mechanisms. For 96d, cages remained at 12 Clinch River (CR), Hurricane Fork (HF), and Dump's Creek (DC) sites upstream and downstream of a coal-fired power plant discharge, coal mining effluent, and coal combustion-related disposal facilities in Carbo, Virginia. Although survivorship was not significantly different between cage types, mean growth of clams in bioboxes was significantly greater overall (p = 0.0157). Despite the difference in growth between the two cage types, both confirmed significant reductions of survivorship and growth directly below the power plant discharge. Additionally, coefficient of variance values for biobox growth data were reduced at most study sites (averages of 16% for bioboxes versus 19% for mesh bags). Our results have implications toward strengthening weight-of-evidence approaches used to link impairment of transplanted bivalves to environmental contaminants. More importantly, these results suggest that ecotoxicological impairment of bivalves transplanted downstream of the coal-fired power plant discharge functioned independently of site-specific substrate provisions.     

A GIS Model of Subsurface Water Potential for Aquatic Resource Inventory,Assessment, and Environmental Management

Biological, chemical, and physical attributes of aquatic ecosystems are often strongly influenced by groundwater sources. Nonetheless, widespread access to predictions of subsurface contributions to rivers, lakes, and wetlands at a scale useful to environmental managers is generally lacking. In this paper, we describe a neighborhood analysis approach for estimating topographic constraints on spatial patterns of recharge and discharge and discuss how this index has proven useful in research, management, and conservation contexts. The Michigan Rivers Inventory subsurface flux model (MRI-DARCY) used digital elevation and hydraulic conductivity inferred from mapped surficial geology to estimate spatial patterns of hydraulic potential. Model predictions were calculated in units of specific discharge (meters per day) for a 30-m²-cell raster map and interpreted as an index of potential subsurface water flux (shallow groundwater and event through-flow). The model was evaluated by comparison with measurements of groundwater-related attributes at watershed, stream segment, and local spatial scales throughout Lower Michigan (USA). Map-based predictions using MRI-DARCY accounted for 85% of the observed variation in base flow from 128 USGS gauges, 69% of the observed variation in discharge accrual from 48 river segments, and 29% of the residual variation in local groundwater flux from 33 locations as measured by hyporheic temperature profiles after factoring out the effects of climate. Although it does not incorporate any information about the actual water table surface, by quantifying spatial variation of key constraints on groundwater-related attributes, the model provides strata for more intensive study, as well as a useful spatial tool for regional and local conservation planning, fisheries management, wetland characterization, and stream assessment.     

Cost-effectiveness Analysis of Reducing the Emission of Nitrogen Oxides in Asia

The purpose of this study is to evaluate cost-effective reduction strategies for nitrogen oxides (NO _x ) in the Asian region. The source-receptor relationships of the Lagrangian “puff” model of long-range transportation, ATMOS-N, were used to calculate the wet/dry deposition of the nitrogen (N) in Asia. Critical loads of N deposition in Asia were calculated from the relationships between the critical load of sulfur (S) and balance of N in and out using the data of S critical load of RAINS-ASIA. The cost functions of N reduction of Asian countries were derived by the regression analysis with the data of cost functions of European countries used in RAINS. In order to assess the environmental impact, the gaps between N deposition and critical load of N were calculated. The emission of NO _x was reduced in some cases of this model, and the changes of gaps between N deposition and critical load were observed as well as the changes of the reduction cost. It is shown that a uniform reduction of NO _x emissions by countries in Asia is not cost-effective strategy.     

Pilot‐scale evaluation using bioaugmentation to enhance PCE dissolution at dover AFB national test site

An Interstate Technology and Regulatory Council (ITRC) forum was recently held that focused on six case studies in which bioremediation of dense nonaqueous‐phase liquids (DNAPLs) was performed; the objective was to demonstrate that there is credible evidence for bioremediation as a viable environmental remediation technology. The first two case studies from the forum have been previously published; this third case study involves a pilot‐scale demonstration that investigated the effects of biological activity on enhancing dissolution of an emplaced tetrachloroethene (PCE) DNAPL source. It used a controlled‐release test cell with PCE as the primary DNAPL in a porous media groundwater system. Both laboratory tests and a field‐scale pilot test demonstrated that bioaugmentation can stimulate complete dechlorination to a nontoxic end product and that the mass flux from a source zone increases when biological dehalorespiration activity is enhanced through nutrient (electron donor) addition and bioaugmentation. All project goals were met. Important achievements include demonstrating the ability to degrade a PCE DNAPL source to ethene and obtaining significant information on the impacts to the microbial populations and corresponding isotope enrichments during biodegradation of a source area. © 2007 Wiley Periodicals, Inc.     

Trail erosion patterns in Great Smoky Mountains National Park

All the maintained trails in Great Smoky Mountains National Park were surveyed for width, depth, and a variety of types of erosion. Trail erosion is related to a number of environmental variables, including vegetation type, elevation, trail slope, and section of the park. Open grass balds and spruce-fir forest are the most erosion-sensitive plant communities, and the xeric oak and pine types are the least sensitive. Trails in virgin or mature forest tend to be in poorer condition than those in successional areas. The most important physical factor is the slope of the trail.Trails in the Tennessee district are in slightly poorer condition, on the average, than those in the North Carolina district, but the Appalachian Trail is more eroded than either. A poor section of the park may have ten times the erosion of a good section. On an allpark basis, water erosion is the most important problem, with 15% of the trail surface affected.A comparison of visitation patterns with trail condition indicates that redistribution of use would help to mitigate some erosion problems. Because trail condition is correlated to physical environmental factors, however, some sites will require intensive maintenance, even if visitation is low.The data from this survey have already been used in environmental analysis of proposed developments within the park and can be applied to long-range planning for the park trail system as a whole.     

CONTROL OF LAKE PHOSPHORUS WITH ALUMINUM SULFATE: DOSE DETERMINATION AND APPLICATION TECHNIQUES1

ABSTRACT: Nutrient diversion does not always bring about prompt and sufficient reduction in lake phosphorus concentration due to recycling from nutrient rich sediments. Certain lakes and reservoirs may continue to experience nuisance algal blooms and require additional restorative steps. The phosphorus precipitation/inactivation technique is a procedure to remove phosphorus from the water column and to control its release from sediments in order to achieve P-limiting conditions to algal growth. Aluminum salts have been used in advanced waste water treatment to remove phosphorus and this technology was extended to lake rehabilitation. Guidelines for dose calculation and application are generally lacking, and are provided in this report. The dose determination suggested here allows maximum application of aluminum to bottom sediments and thus emphasizes long term control of phosphorus recycling. Dose can be calculated directly from the alkalinity of the water to be treated. Titration of lake water samples of Varying alkalinity allows the establishment of the relationship between residual dissolved aluminum, alkalinity, and dose which can then be employed for lake scale applications of alum to lakes and reservoirs. Application equipment and procedures are described. These depend on site characteristics and treatment objectives and include lakeside stores, a distribution pipe, and an application barge and manifold. Alum may also be used to meet other restoration objectives including the treatment of problem flows and the reduction of particulate concentrations.     

Colorful displays signal male quality in a tropical anole lizard

Parasites influence colorful ornaments and their behavioral display in many animal hosts. Because coloration and display behavior are often critical components of communication, variation in these traits may have important implications for individual fitness, yet it remains unclear whether such traits are signals of quality in many taxa. We investigated the association between ectoparasitic mite load and the color and behavioral use of the throat fan (dewlap) by male Anolis brevirostris lizards. We found that heavily parasitized lizards exhibited lower body condition, duller dewlaps, and less frequent dewlap displays than less parasitized individuals. Our results thus suggest that highly parasitized individuals invest less in both ornamental color and behavioral display of that color. Because the two components of the signal simultaneously provide information on male quality, this study provides novel support for the long-standing hypothesis that colorful traits may function as social or sexual signals in reptiles.