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Residential areas are being increasingly impacted by wildfire smoke that causes hazardous local ambient air quality conditions. Poor outdoor air quality also exacerbates the quality of indoor air as smoke particles penetrate the building envelope or the heating, ventilation, and air-conditioning (HVAC) filtration systems. In this work, we investigate the impact of wildfire-affected poor ambient air quality on indoor air particulate matter during a wildfire episode in June 2015 in interior Alaska. We measured size-resolved (0.3–10 μm) particle number counts (PNC; numbers/cm3) and calculated particle mass concentrations (PMC; μg/m3) outside and inside of three buildings in Fairbanks, Alaska, during this summer wildfire event. For comparison, the measurements were repeated during a no-wildfire period in summer 2017. Our results show that the fire episode increased the total PNC by factors of 189.4–244 in the outdoor air and by 19.5–150 in the indoor air compared to the total PNC measured during a non-fire season. The PNC was primarily dominated by particles in the size range 0.3–1 μm (> 99%) at all locations during the fire season, whereas the PMC was dominated by particles in the size range from 2.5 to 10 μm (40–67%). The indoor to outdoor ratio (I/O) of PNC during the fire season was significantly lower for an unventilated building (I/O = 0.13 ± 0.001) as compared to those with active (filtered) ventilation (I/O = 0.76 ± 0.11 and 0.62 ± 0.02), suggesting that lower efficiency filters (

Racial/ethnic minority girls have a history of being underrepresented in STEM. Yet, there is a dearth of research that identifies the mathematics experiences that predict being on a STEM pipeline. Analyzing data from the Educational Longitudinal Study (ELS: 2002), we examined the relationship between mathematics attitudes, beliefs, and enrichment activities and being on a STEM pipeline among racial/ethnic minority girls. The findings indicated that for Black and Latinx girls, higher levels of mathematics self-efficacy beliefs were associated with being on a STEM pipeline. For American Indian/Alaska Native girls, endorsing a growth mindset was associated with being on a STEM pipeline. For Asian, Hawaii/Pacific Islander girls, mathematics enjoyment was associated with being on a STEM pipeline. Yet, endorsing higher levels of participation in mathematics enrichment activities and mathematics self-efficacy beliefs was associated with lower endorsements of being on a STEM pipeline for Black and American Indian/Alaska Native girls, respectively. Results build on previous work by highlighting important mathematics experiences that impact being on a STEM pipeline for racial/ethnic minority girls.

Poor air quality in Alaska’s remote communities due to road dust is one of the top environmental concerns of residents in these communities. Most communities are disconnected from the road network, with community roads that are predominantly unpaved. In Alaska, high costs limit widespread paving of roads, leaving communities to rely on alternative dust control strategies. The goals for this study were to assess the magnitude and impact of the dust problem in rural Alaska and use a diversity of experience, including regulatory, research, engineering, and cultural, to develop a road-dust management approach for rural Alaska. The plan incorporates different levels of dust management: institutional controls, road watering, chemical dust suppressants, and road surface stabilization. Geographical zones where use of each different dust management level will be most appropriate are identified based on rainfall frequency. Approximately 50% of Alaska’s communities can manage road dust with institutional controls and road watering. Many of the road-dust management ideas presented are transferable to other global regions that experience similar economic and community access challenges as Alaska.

Intrusion of volatile organic compounds in the gas phase has impacted many buildings in many different locations. Various building and environmental factors such as buoyancy of heated air and changes in barometric pressure can influence indoor air concentrations due to vapor intrusion in these buildings resulting in seasonal and daily variability. One environmental factor that previous research has not adequately addressed is soil temperature. In this study we present two northern region study sites where the seasonal trends in indoor air VOC concentrations positively correlate with soil temperature, and short-term (days) variations are associated with barometric pressure changes. We present simple and multivariate linear relationships of indoor air concentrations as a function of soil temperature and barometric pressure. Results from this study show that small changes in soil temperature can result in relatively large changes in indoor air VOC concentrations where the gas phase VOCs are sourced from non-aqueous phase liquids contained in the soil. We use the results from this study to show that a five degree Celsius increase in soil temperature, a variation in soil temperature that is possible in many climatic regions, results in a two-fold increase in indoor air VOC concentrations. Additionally, analysis provides insight into how building ventilation, diffusion, and the relative rate of soil-gas flow across the slab both from the subsurface into the building and from the building into the subsurface impact short term variations in concentrations. With these results we are able to provide monitoring recommendations for practitioners.

The novel coronavirus SARS-CoV-2, the causative agent of COVID-19, emerged in the human population in December 2019 and spread worldwide within a few short months. Much of the public health focus for preventing and mitigating the spread of COVID-19 has been on individual and collective behaviors, such as social distancing, mask-wearing, and hygiene. It is important to recognize that these behaviors and health outcomes occur within broader social and environmental contexts, and factors within local communities such as regional policy, historical context, cultural beliefs, and natural- and built environmental characteristics affect underlying population health and the spread of disease. For example, the COVID-19 pandemic has renewed attention to the importance of secure water and sanitation services in protecting human health; many remote Alaskan communities are particularly vulnerable to infectious disease transmission because of inadequate water and sanitation services. In addition, there are a number of socio-economic, physical, and infrastructure factors in rural Alaska (e.g., remoteness, household overcrowding, climate change impacts, limited medical facilities, and high prevalence of chronic diseases) that contribute to the potential for more severe COVID-19 disease outcomes in these predominantly Alaska Native communities., Graphical abstract Unlabelled Image

Alternative water supply, storage, and treatment (AWSST) systems, which utilize aquifers to supply, store, and naturally treat water, are increasingly being implemented globally to address water scarcity and safety. The failure of some AWSST systems to meet water quality expectations was caused by conceptual model error, in which local hydrogeological conditions were less favorable than recognized or considered during project feasibility assessments, economic analyses, and design. More successful implementation of AWSST projects requires that conceptual model error be explicitly and rigorously addressed. Recommended approaches to addressing conceptual model uncertainty include more detailed aquifer characterization, recognition of a wide suite of possible alternative conceptual models, and then screening the models as to whether or not they are plausible and relevant in terms of materially impacting predictive results. Subjective professional judgement remains the basis for assigning probabilities to relevant conceptual models (contingencies).

Releases of diesel fuel in the Arctic tundra are a common occurrence. Response to such releases in this region typically involves excavating the contaminated soil and backfilling the excavation with clean material. Owing to the lack of clean stockpiled native soils, coarse-grained soil (aggregate) used for the construction of roads and foundation pads may be the only backfill material available. Backfilling the excavated zone with soil that has different characteristics than the surrounding native soil, combined with the removal of natural vegetation, may drastically change the maximum thaw depth reached during the thawing season, altering the underlying permafrost condition. At the extreme, such measures in areas of ground ice can result in the creation of thermokarsting. We measured maximum thaw depths in aggregate backfill at a diesel spill site located in northwestern Alaska. Using an analytic solution, we investigated the reduction in maximum thaw depth by placing a relatively thin layer (0.5 m) of fine-grained native soil over the aggregate backfill. Such a practice reduces the maximum thaw depth by as much as 1.4 m over backfilling with aggregate only.

Aminopyralid is used in Alaska to control certain invasive weed species; however it appears to have an extended soil half-life in interior Alaska resulting in carry-over injury in potatoes. Field studies at three experiment stations in Delta Junction, Fairbanks, and Palmer, Alaska were established to determine the dose–response of weeds and above and below ground potato growth to soil-applied aminopyralid (0, 8, 15, 31, 62, and 123 g ae ha−1) . Both prostrate knotweed and narrowleaf hawksbeard were susceptible to aminopyralid. At Delta Junction and Fairbanks, visual injury of potatoes greater than 25 % was observed at 15 g ae ha−1 aminopyralid, whereas at Palmer visual injury was greater than 40 % at 8 g ae ha−1, the lowest rate tested. Potato tuber production was reduced by aminopyralid at rates of 15 g ae ha−1 and above at both Delta Junction and Palmer. Sub-samples of potato tubers from Delta Junction and Palmer were analyzed for aminopyralid content and grown out to determine if aminopyralid in tubers would reduce subsequent growth. The aminopyralid concentration in potato tubers increased with increasing field application rates, with 30 ppb extracted from tubers grown at the highest application rate (123 g ae ha−1). All plants grown from daughter tubers except from control plots in Palmer exhibited injury symptoms. The number of emerged shoots, and shoot height decreased with increasing aminopyralid concentrations in the tuber, with injury rates greater than 70 % at 8 g ae ha−1.

Alternative landfill covers utilizing evapotranspiration (ET) as the primary mechanism for protecting the waste layer from aerial moisture represent promising tools for cold region solid waste management. However, ET covers have not been evaluated for use in subarctic climates. As the functionality of an ET cover is driven primarily by climactic variables, climate-specific field tests are required prior to widespread implementation. The objective of this study was to evaluate the four-year performance of two competing pilot-scale landfill covers built atop drainage lysimeters near Anchorage, AK. The compacted soil cover (CSC) was designed and constructed according to standards prescribed by Alaska solid waste regulations. The alternative ET cover design was based upon a preliminary modeling study. After four years, the two adjacent lysimeters had each received a total of 1636 mm precipitation. Over that period, 201 mm moisture drained from the ET lysimeter, compared to 292 mm in the CSC lysimeter. The difference in drainage rates between the two covers was most apparent during the autumn season, when the drainage rates for both covers were at their annual maximum. The lower autumn and annual drainage rates observed in the ET lysimeter after the first year were potentially due to higher moisture storage capacity in the ET cover soils and/or formation of preferential flow paths in the CSC soils. Analysis of soil temperature, precipitation, and drainage data indicated that negligible amounts of winter precipitation infiltrated the ET cover during winter, and that the frozen soils promoted runoff over drainage during the spring melt. These results indicate that similar ET cover designs merit consideration for broader use in subarctic conditions.

In order to test the efficacy ofa cold-region evapotranspiration (ET) landfill cover against a conventional compacted clay (CCL) landfill cover, two pilot scale covers were constructed in side-by-side basin lysimeters (20m x 10m x 2m) at a site in Anchorage, Alaska. The primary basis of comparison between the two lysimeters was the percolation of moisture from the bottom of each lysimeter. Between 30 April 2005 and 16 May 2006, 51.5 mm of water percolated from the ET lysimeter, compared to 50.6 mm for the the CCL lysimeter. This difference was not found to be significant at the 95% confidence level. As part of the project, electrical resistivity tomography (ERT) was utilized to measure and map soil moisture in ET lysimeter cross sections. The ERT-generated cross sections were found to accurately predict the onset and duration of lysimeter percolation. Moreover, ERT-generated soil moisture values demonstrated a strong linear relationship to lysimeter percolation rates (R-Squared = 0.92). Consequently, ERT is proposed as a reliable tool for assessing the function of field scale ET covers in the absence of drainage measurement devices.

At a site with discontinuous permafrost in Fairbanks, Alaska, releases of trichloroethene (TCE), an industrial solvent, have caused contamination of the groundwater. The objective of this study was to investigate the relationship between the migration pathway of the TCE groundwater plume and the distribution of the discontinuous permafrost at the site. The TCE plume configuration is substantially different than what regional hydrology trends would predict. Using GIS, we conducted a geostatistical analysis of field data collected during soil-boring installations and groundwater monitoring well sampling. With the analysis results, we constructed maps of the permafrost-table elevation (top of permafrost) and of the groundwater gradients and TCE concentrations from multiyear groundwater sampling events. The plume concentrations and groundwater gradients were overlain on the permafrost map to correlate permafrost locations with groundwater movement and the spatial distribution of TCE moving with groundwater. Correlation of the overlay maps revealed converging and diverging groundwater flow in response to the permafrost-table distribution, the absence of groundwater contamination in areas with a high permafrost-table elevation, and channeling of contaminants and water between areas of permafrost. In addition, we measured groundwater elevations in nested wells to quantify vertical gradients affecting TCE migration. At one set of nested wells down gradient from an area of permafrost we measured an upward vertical gradient indicating recharge of groundwater from the subpermafrost region of the aquifer causing dilution of the plume. The study indicates that the variable distribution of the permafrost is affecting the way groundwater and TCE move through the aquifer. Consequently, changes to the permafrost configuration due to thawing would likely affect both groundwater movement and TCE migration, and areas that were contaminant-free may become susceptible to contamination.

The use of triclopyr for the removal of woody and broad-leaf vegetation in right-of-ways and agricultural settings has been proposed for Alaska. Triclopyr concentrations in soil after application are of concern because residual herbicide may affect growth of subsequent vegetation. In order to measure triclopyr residues in soil and determine the amount of herbicide taken up by the plant, soil bioassays were developed. Four agricultural species, turnip, lettuce, mustard, and radish, were tested to determine sensitivity to triclopyr in a 1-wk bioassay. The sensitivity (I50) of turnip, lettuce, mustard, and radish was 0.33 ± 0.05 kg ai ha−1, 0.78 ± 0.11 kg ai ha−1, 0.78 ± 0.07 kg ai ha−1, and 0.85 ± 0.10 kg ai ha−1 (mean ± SE), respectively. Mustard was the most consistent crop in the bioassay with a midrange response to triclopyr and lowest standard deviation for germination as compared to the other species. Thus, it was used in a bioassay to determine triclopyr concentrations in a field trial. The bioassay of mustard closely matched residual amounts of triclopyr in a field trial determined by chemical extraction. Estimates of residual triclopyr concentrations using the bioassay method were sometimes less than the triclopyr concentration determined using a chemical extraction. These differences in concentrations were most evident after spring thaw when the chemical extraction determined there was enough triclopyr in the soil to reduce mustard growth over 60%, yet the bioassay measured only a 10% reduction. The chemical extraction method may have identified nonphototoxic metabolites of triclopyr to be the herbicidal triclopyr acid. These methods, when analyzed together with a dose–response curve, offer a more complete picture of triclopyr residues and the potential for carryover injury to other plant species.

Knowledge of the factors that influence the diffusion of contaminants, such as the diffusivity and the connected porosity, is crucial to modeling the long-term fate and transport of contaminants in subsurface systems with small or negligible advective flow, such as in fractured crystalline rock. Fractured rock is naturally heterogeneous, and hence, understanding the diffusivity of a molecule through this material (or the formation factor of the medium) becomes a complex problem, with critical concerns about the scale of laboratory measurements and about the spatial variability of these measurements relative to the scale needed for fate and transport modeling. This study employed both electrical and tracer-based laboratory methods to investigate the effects of scale and pore system connectivity on the diffusivity for volcanic matrix rock derived from the study site, a former underground nuclear test site at Amchitka Island, Alaska. The results of these investigations indicate a relatively well-connected pore system with scale effects generally limited to approximately 6 cm lengths and well-correlated to observed heterogeneous features. An important conclusion resulting from this study, however, is that there is a potential for the estimated diffusivity to be misrepresented by an order of magnitude if multiple samples or longer sample lengths are not used. Given the relatively large number of measurements resulting from these investigations, an analysis of the probability density function (PDF) of the diffusivity was possible. The PDF of the diffusivity was shown to generally follow a normal distribution for individual geologic layers. However, when all of the geologic layers are considered together, the distribution of the subsurface as a whole was shown to follow a lognormal distribution due to the order of magnitude differences amongst the layers. An understanding of these distributions is essential for future stochastic modeling efforts.

Amchitka Island, Alaska, is a historical underground nuclear test site. Three underground tests were conducted there by the United States Atomic Energy Commission, now US Department of Energy (USDOE), between 1965 and 1971. These were Long Shot, an 80 kiloton detonation; Milrow, a 1 megaton detonation; and Cannikin, a 5 megaton detonation. Subsequent to these tests, several scientific assessments have been conducted regarding the impacts of the tests on the terrestrial and marine environments surrounding the island. However, many citizens and groups still voice concerns over the potential for detrimental effects on human and ecological health. In its responsibility for the long term protection of human and ecological health consequent to its nuclear programme, USDOE has recently prepared a plan for the long term surveillance and monitoring of the site. The purpose of this paper is to summarise the history of the island, specifically with regards to its use as a nuclear test site, to summarise the results of investigative activities following testing, to summarise USDOE's plan for surveillance and monitoring, and to offer the authors' viewpoints on the long term stewardship of the island. The authors deemed the stewardship plan to be essentially protective of human and ecological health; however, they recommend a stronger commitment to site oversight and review, as well as to future research, for addressing uncertainties remaining at the island.

People living without piped water and sewer can be at increased risk for diseases transmitted via the fecal-oral route. One rural Alaskan community that relies on hauling water into homes and sewage from homes was studied to determine the pathways of fecal contamination of drinking water and the human environment so that barriers can be established to protect health. Samples were tested for the fecal indicator, Escherichia coli, and the less specific indicator group, total coliforms. Shoes transported fecal contamination from outside to floor material inside buildings. Contamination in puddles on the road, in conjunction with contamination found on all-terrain vehicle (ATV) tires, supports vehicle traffic as a mechanism for transporting contamination from the dumpsite or other source areas to the rest of the community. The abundance of fecal bacteria transported around the community on shoes and ATV tires suggests that centralized measures for waste disposal as well as shoe removal in buildings could improve sanitation and health in the community.

Knowledge of how contaminants spread through frozen ground is required to better protect water quality and environmental health. This study investigates the effect of pore ice on vertical and lateral movement of a petroleum product in coarse-grained soils. Time lapse photography is used to track diesel product migrating through two-dimensional flumes packed with wetted soil frozen to −5°C. Results from these flow studies indicate that the presence of pore ice blocks pore space, causing increased lateral movement of petroleum, creates preferential pathways resulting in increased petroleum penetration depths, and can restrict infiltration of petroleum into soils with high ice saturations.

People living without piped water and sewer can be at increased risk for diseases transmitted by the fecal-oral route. One Alaskan community that relies on hauled water and sewage was studied to determine the pathways of fecal contamination of drinking water and the human environment so that barriers can be established to protect human health. Samples were tested for the fecal indicators Escherichia coli and Enterococcus. Several samples were tested for the pathogens Giardia lamblia and Cryptosporidium parvum and source tracking methods were employed. Surface water flow transported bacteria within the community during spring thaw and human fecal contamination was detected in town, but flow from the dump did not appear to contribute to contamination in town. Within the home, fecal bacteria were found on water dippers, kitchen counters and floors, and in hand-washing basins. Giardia was found at the dump, but not in water from the river adjacent to the community. Exposure to fecal contamination could be red...

Survival characteristics of total coliform bacteria in soil samples, with different moisture contents (24–49%) and at different temperatures (from −28 to 20°C ), were studied. The study showed that a significant fraction of coliform bacteria survive for more than six months in soil at subfreezing temperatures. Survival of total coliform bacteria at subfreezing temperatures decreased with an increase in moisture content and an increase in temperature. For 24% moisture, approximately 66% of the coliforms survived at −28°C after 170 days, whereas less than 0.1% survived at room temperature. First-order die-off rate constants varied between 0.041/day at room temperature and 0.002/day from −15 to −28°C (for 24% moisture). The impact of temperature on the die-off rate constant was described by the Arrhenius equation. The high survival at subfreezing temperatures indicates that fecal bacteria at honeybucket dumpsites may survive throughout the Alaskan winter which may lead to the contamination of water sources d...

Arctic soil samples were experimentally subjected to freeze–thaw cycles (FTC) between + 5 °C and − 5 °C and to stable temperature regimes of + 5 °C and − 5 °C to investigate how the microorganisms' ability to mineralize oil contamination is affected by different temperature regimes. Hydrocarbon mineralization was monitored in oil contaminated soil microcosms spiked with radiolabeled hexadecane and phenanthrene. Both fertilized and unfertilized soils were used. Mineralization of radiolabeled compounds was demonstrated in all treatments. In soils kept stable at − 5 °C hydrocarbon mineralization was low, but detectable for hexadecane and phenanthrene, both in fertilized and unfertilized soil. Greatest mineralization rates were determined in fertilized soil samples kept stable at + 5 °C where up to 54 mg hexadecane/kg/day and 11 mg phenanthrene/kg/day were measured. Mineralization did not come to a complete stop when the temperature was changed to − 5 °C, but was considerably reduced compared to the + 5 °C mineralization rates. FTC stimulated hexadecane mineralization compared to constant temperature. Phenanthrene mineralization, on the other hand, was constrained by FTC. FTC did not seem to affect the microbial populations in the soil in a negative way, and the total number of cultivable microorganisms increased during the experimental period. The freeze–thaw experiments demonstrate that mineralization of both hexadecane and phenanthrene is occurring in soils undergoing seasonal temperature fluctuations, both above and below freezing temperatures.

Amchitka Island, in Alaska, was used for underground nuclear testing from 1965 to 1971. Since the test program concluded, there have been concerns about the possible release of radionuclides into the marine environment of the Aleutian Islands. The hydrogeology of islands such as Amchitka is characterized by a layer of freshwater overlying a saltwater layer, with the salinity increasing across a transition zone (TZ). Hydrogeologic modeling can provide an estimate of the timing and amount of radionuclide release from the explosions beneath Amchitka Island. This modeling is inconclusive because of a lack of information regarding subsurface structure. To address this problem, magnetotelluric (MT) data were collected on Amchitka Island in 2004. Broadband MT data were recorded on profiles passing through three explosion sites to give information about subsurface porosity and salinity. A 2D MT inversion produced models of sub-surface electrical resistivity and showed a pattern of increasing, decreasing, and increasing resistivity with depth at each test site. The depth at which resistivity begins to decrease defines the top of the TZ. The deeper increase in resistivity approximates the base of the TZ. The depths of the top and bottom of the TZ were determined as follows: Cannikin 900–2500 m; Long Shot 600–1700 m; Milrow 900–1700 m. Uncertainties were estimated for these depths. Effective porosities were also estimated and ranged from 10%–20% at the surface to 1%–3% at 3-km depth. These porosities are higher than those assumed in several hydrogeologic models, and give longer transit times from the explosion to the marine environment. Subject to the limits of the analysis, it appears that each of the cavities resulting from underground nuclear explosions is located in the TZ from fresh to saltwater. This implies shorter transit times to the marine environment than if the detonations had been located in the saltwater layer.

Understanding the formation of pore ice in coarse grained soils is important to geotechnical and geo-environmental projects such as the construction of roads, airstrips and gravel foundations as well as the treatment of contaminated soils in the arctic, sub-arctic, alpine and northern regions. The amount of pore ice present impacts the strength characteristics of the soils as well as the flow of fluid through soil. Tests have been conducted to qualify the impact of gradation, temperature, compaction and initial moisture content on the formation of pore ice in coarse grained soils. The purpose of this study was to prepare a conceptual model of the freezing mechanism in coarse grained soils and to qualify the parameters that influence the ice formation. Results from this study indicate that the presence of fine particles in a coarse grained soil greatly impact the depth at which the pore space initially becomes saturated with ice. A conceptual model was developed and its application is shown with regards to the process of thaw weakening in roads and the creation of preferential flow paths in permeable reactive barriers.

Over the past several decades, soil vapor extraction (SVE) systems have successfully reduced the mass of volatile organic compounds in contaminated soils at many sites. However, predicting when operation of these systems should end once mass removal rates decline and become asymptotic to some low value is still a difficult task. To help make this decision, a simple decision model has been derived from a more rigorous cost-risk-based objective function that requires extensive Monte Carlo analyses. Use of the simple model to make a decision on continued operation does not require the same extensive modeling effort. Yet, use of the model does require the contaminant removal rate to be asymptotic to some low value indicating that the removal process has become dominated by diffusion from relatively low permeable soil. At this stage of the removal process, the SVE system should be replaced with an alternative approach if the cost of this alternative approach is less than the capital cost of continued SVE system operation. Applicability of the simple model is discussed through a comparison of the results predicted by the simple model for an operating SVE system to the rigorous results determined with the objective function. Results from this study show that under most conditions the simple model can be used to make a decision of whether a SVE system should continue to operate.

Creative remediation schemes have been implemented with success at petroleum-contaminated sites in Alaska and Canada during the past decade. Contaminated media have been landfarmed, amended with fertilizers, augmented with microbial products, and manipulated with engineered systems. Phytoremediation developments and use of biodegradable synthetic and polymeric resins for potential use with petroleum and xenobiotic contaminants are on the horizon. Treatment of supra-permafrost water and melt-water runoff with permeable reactive barriers and partitioning bioreactors is now possible. Cost and time limitations will likely continue to drive remediation decisions in the Arctic. Environmental policy, environmental constraints, and cost will dictate what technologies are appropriate for Antarctic clean-up, although the pressure of time is less acute because land transfer and liability are not drivers. This paper discusses some recent advances in remediation engineering for use in polar regions. Conceptual models are presented, and case study treatment costs and durations are highlighted to aid environmental decision-making.

In today’s increasingly competitive markets, greater emphasis is being placed on customer service as a means of achieving competitive advantage. Many organizations believe that e-business can provide opportunities to improve customer service operations by enabling them to get closer to the customer and enhance the organization-to-customer contact experience. However, use of the Internet fundamentally changes the nature of the customer contact experience. This article investigates this phenomenon from an operations management perspective, by examining the customer service encounter during the business processes of ordering and delivering in e-business. Empirical results from case research investigating eight companies that use e-business in their customer service operations are reported and discussed. The article concludes that unless the emotional aspects of customer service are considered alongside the functional, then barriers to enhanced customer service in e-business will not be overcome.

Past documented laboratory measurements have shown movement of petroleum hydrocarbons to the freezing front in contaminated freezing soils. The mechanisms that are, in part, responsible for the increased contaminant concentration at the freezing front are illustrated in this study with a mass-balance model. Results from this quantitative analysis show that this concentration increase is due to exclusion of petroleum hydrocarbon from the crystalline ice structure and from physical displacement of liquid petroleum hydrocarbon from the pore space as water freezes and expands into ice. Consequences of this process in relation to contaminant migration in freezing soils through time are discussed.

In North American cold regions, terrestrial spill-response tactics have evolved through clean-up experience with crude oil and refined petroleum products. Alaska has developed response tactics as guidelines for clean-up of petroleum-based spills. Generic application of any response tactic without regard for season, site-specific conditions, and equipment limitations can further damage an ecosystem. For example, the practice of igniting and burning petroleum product spilled onto frozen tundra without consideration of the anthropogenic effect on the surface energy balance may actually increase the vertical migration of the spilled product. Prior to application of any mitigation strategy to a release of petroleum product, the movement of the product through freezing soil needs to be better understood. Case studies are presented, and lessons learned from them are discussed.

Soil vapor extraction (SVE) has become an acceptable method of removing volatile organic compounds from soil. However, determining the length of time these systems should operate has been historically difficult. This paper presents a procedure for determining this length of operation. The procedure incorporates principles of uncertainty analysis, contaminant transport, and decision theory. An example is provided to illustrate the use of the procedure. Additional analysis of the results shows that a simple calculation can be made that will determine if a SVE system that has been operating for a period of time and is in the later stages of contaminant removal should continue to operate. This calculation consists of dividing the cost of treating the remaining contaminated soil with an alternative method (e.g., ex situ biological treatment) by the annual operation and maintenance cost and comparing this ratio to the inverse of the interest rate. If this ratio is less than the inverse of the interest rate the system should be shut off.

This paper proposes a risk-cost approach for the design of soil vapor extraction (SVE) systems that takes into account uncertainties in the soil properties. The proposed design methodology consists of three separate models: a soil-gas flow and vapor transport model, a parameter uncertainty model, and a decision model based on a risk-cost objective function. A description of each of these models is provided and an example using a hypothetical scenario is given to illustrate the use of the methodology. Results from the example show that the methodology is suited for determining the number, location, and spacing of SVE extraction wells. The methodology can also be used to size the vacuum blower to be used and to predict when the SVE system should be shut off.

Currently, there is increasing attention to the environmental impact of the recycling scenarios used for end-of-life electric and electronic (E&E) products. In anticipation of future disposal and recycling concerns due to the increasing consumption of E&E equipment, a systematic management tool is essential to effectively maximize the recyclability of end-of-life products and minimize the environmental impact of recycling and disposal. In this paper, a generic decision-making methodology is developed for material recycling and disposition of E&E products. The research results in an optimal recycling scenario for general end-of-life E&E products based on the combination of environmental impact, recycling feasibility, and intensity of resource recovery. Three major factors are considered during decision making: environmental impact, related cost, and recoverable materials. These three factors are integrated through a fuzzy membership function and Analytic Hierarchy Process (AHP). The research is based on a project supported by the Amarillo National Resource Center for Plutonium. A computerized prototype decision-making model is developed based on the proposed methodology. The research result can be extended to the recycling process of all kinds of electromechanical scraps. Potentially, the proposed methodology can be adopted for assessing various recycling alternatives to provide environmentally friendly solutions.

Lead still remains one of the most thoroughly investigated heavy metals in the environment. Although the identification of lead in soil is a routine matter, its environmental consequence is still much debated because of its potential mobility. We have investigated lead- and copper-contaminated soil from two different areas. One was in an urban area, which formerly had a lead smelter within the city. The other a firing range, in which hundreds of thousands of rounds were fired into a very large mound known as a berm. Homogeneity tests, depth profiles, and Pb-Cu correlations are discussed.

In this paper, we briefly describe the clean-up and remediation of a major watershed in Kazakhstan, the Nura River, that was impacted by rapid industrial development during the Soviet era, leaving a legacy of mercury pollution impacting hundreds of thousands of people. Fresh waters, including rivers, lakes, glaciers, groundwater, man-made reservoirs and canals represent less than 3 percent of the earth’s water. Watersheds are closely linked ecosystems that are natural units of analysis and management. Over the last century, the use of freshwater systems has grown at an unprecedented rate to supply and support industrial and agricultural production. Remediation of damaged watersheds and sustainable water management are important tools to minimize the impact of the human activities, especially industrial activities, on the ecosystem services provided by a healthy watershed. Based on engineering reports and data, we discuss the importance of adaptive management strategies, flexibility, and place-based Hg remediation criteria, as well as the value of stakeholder input in a polycentric project management approach.

[1] Temporal atmospheric pressure variations introduce an artifact into percolation measurements in free-draining lysimeters. This anomaly is associated with transient pressure gradients that occur as fluid and gas pressures within the lysimeter equilibrate with atmospheric pressure changes at the drain. On the basis of harmonic (Fourier) analysis of a large (20 m × 10 m × 1.8 m) free-draining lysimeter, hourly percolation was maximally affected by pressure variations of ∼2 cycles per day, with the effect decreasing with decreasing frequency. Compared to the calculated pressure differences at the drain, the measured phase delay between percolation and the atmospheric pressure was less by ∼45°, which we attribute to an additional phase lag existing between the percolation and pressure difference at the drain. These pressure-induced changes in percolation rate can influence the outcome of water balances conducted via free-draining lysimeters.

[1] Diffusion coefficients and effective, or transport, porosities are important parameters in the assessment of the fate and transport of contaminants in fractured rock systems and when contaminant transport needs to be considered in zones of low to negligible advective flows. This study presents and discusses various solutions, analytical and semianalytical, to Fick's law for the typical through-diffusion experiment and applies these solutions to the results of three through-diffusion experimental data sets. These through-diffusion experiments were conducted on two natural breccia samples, with bulk measured porosities of approximately 13.7% and 16.8%, and one manufactured porous plate sample with a bulk measured porosity of 40.9%, such that the samples displayed order of magnitude differences in their diffusivities. For each experiment, the derived effective porosities and intrinsic diffusion coefficients for each method are compared. It was shown that the semianalytical solution provides an improved method for reliably estimating the effective porosity from through-diffusion experimental data; however, there is little difference between methods in the derived intrinsic diffusion coefficients.

Dust produced from unpaved roads in rural Alaska is impacting the quality of life in many Alaskan and other villages in cold regions. Not only does dust emanating from unpaved roads cause respiratory ailments, but also impacts subsistence food storage and sources as well as safety since dust impacts visibility on village streets. Loss of fine particles also greatly impacts the quality of road surfaces creating increased maintenance costs. Replacing the fines content in unpaved road surfaces is costly owing to the lack of suitable material and equipment in many villages. The expectation for many communities is that paving their roads will solve their problems. In some cases this may be possible. In many rural environments, however, lack of suitable material or cost prohibitive sources, unsuitable foundation materials or inability to maintain the improved roads preclude pavement as an option. A suitable option for many rural villages may be dust control palliatives and institutional controls. However, there is little consensus on how to identify and measure the effectiveness, economics, and environmental impacts of dust control approaches that are compatible with the subsistence lifestyle common in remote rural communities in Alaska and other cold regions. Our objective in this ongoing study is to evaluate different dust control methods used in rural Alaska. These dust control methods include various synthetic polymer type palliatives, calcium chloride, and institutional controls. This paper presents current efforts to quantify and qualify the effectiveness of dust control measures. Of the different dust control methods, the Alaska Department of Transportation and Public Facilities (AKDOT&PF) has the most experience with calcium chloride (CaCl2). Salts such as CaCl2 (magnesium chloride is another common dust control salt used by others) control dust by adsorbing and retaining moisture in the aggregate surfacing material. These compounds are most effective at suppressing dust when the relative humidity is greater than around 30 to 40 percent (Rushing and Tingle, 2006). During morning hours when relative humidity is typically high and temperatures are low, moisture is retained in the salt treated road surface. As the temperatures rise and relative humidity drops in the afternoon, moisture losses by evaporation from the treated road surface are reduced in comparison to untreated road surfaces. Synthetic polymers comprise several different compounds that promote soil particle binding. Several different products are provided by vendors under the names EK-35, EnviroKleen, Durasoil among others. The compositions of these compounds are typically proprietary. The fraction of loftable fine particles is reduced by the aggregating action of the palliative. Anyone who has driven on unpaved roads has experienced the effect vehicle speed has on the quantity of fine particles lofted by the vehicle. Control of speeds on rural roadways when possible is one of the least expensive means to control dust.

A novel modification of the conventional counter-current air-stripping process, introduced as “cascade air-stripping” is proposed for cost-effective removal of semi and low volatile organic contami...

Introduction Movement of petroleum through non-freezing soils has been studied extensively over the last several decades. Little work has been done on understanding how petroleum moves through seasonal freezing soils (active layer) and frozen soil (permafrost). Petroleum migration through active layer and permafrost soils is influenced by the formation and presence of ice at all scales. At the millimeter scale, ice in pore spaces will either interrupt downward migration causing petroleum to spread laterally, or impede petroleum movement altogether due to the lack of open pore space. Segregated ice at centimeter-to-meter scales will most likely cause the contamination to spread laterally in frozen soils. Segregated ice formation in the active layer can also generate fissures that will enhance petroleum movement when the soil is thawed. At larger scales, discontinuous and continuous permafrost will slow, redirect, or impede contaminant migration. Understanding the impact freezing and frozen soil conditions have on petroleum movement through soils is necessary to regulation, assessment, and cleanup of contaminated soil and groundwater. A good example of this impact is provided when considering natural attenuation. Seasonal ice and post-cryogenic structure present in active layer soil will influence the movement of petroleum and dissolved compounds, thereby impacting the design of monitoring systems to track natural attenuation. Moreover, cold soil temperatures will slow the physical weathering of compounds in the subsurface. Cleanup levels established for cold regions contaminated soil (Chapter 1) and any remediation plan developed for these sites must account for these impacts.

Introduction It is well established that microbial activity is slower at low temperatures, and that there is a corresponding decrease in biodegradation rates (Paul and Clark 1996; Walworth et al . 1999; Scow 1982; Ferguson et al . 2003b; discussed in Chapter 4). As temperatures fall to near the freezing point of water, biomineralization of hydrocarbons practically ceases. Evaporation rates are also slower at low temperature, although diesel products and more volatile fuels continue to volatilize below 0 °C. For most cold regions, soil is typically unfrozen for only 6–8 weeks, affording a short in situ or passive ex situ treatment season. Even when the ground is thawed, temperatures are generally lower than optimal for hydrocarbon-degrading bacteria (Braddock et al . 2001; Rike et al . 2003). At their simplest, thermally enhanced bioremediation schemes aim to increase microbial activity by increasing soil temperatures and extending the period when the ground is unfrozen. Modern integrated designs go much further – they typically incorporate some form of venting to promote volatilization, and deliver nutrients, oxygen, and water to hydrocarbon-degrading bacteria in attempts to optimize bioactivity. They are also designed to prevent off-site migration of contaminants and nutrient-enriched waters. Relative to other remediation options, thermally enhanced bioremediation is a low-cost treatment option (see Chapter 1, Figure 1.1). It is typically much cheaper than bulk extraction and disposal or on-site combustion/desorption treatments, perhaps by a factor of five or more, but approximately two to four times more expensive than landfarming (Chapter 9).

Introduction Oil and fuel spills are among the most extensive and environmentally damaging pollution problems in cold regions and are recognized as potential threats to human and ecosystem health. It is generally thought that spills are more damaging in cold regions, and that ecosystem recovery is slower than in warmer climates (AMAP 1998; Det Norske Veritas 2003). Slow natural attenuation rates mean that petroleum concentrations remain high for many years, and site managers are therefore often forced to select among a range of more active remediation options, each of which involves a trade-off between cost and treatment time (Figure 11). The acceptable treatment timeline is usually dictated by financial circumstance, perceived risks, regulatory pressure, or transfer of land ownership. In situations where remediation and site closure are not urgent, natural attenuation is often considered an option. However, for many cold region sites, contaminants rapidly migrate off-site (Gore et al . 1999; Snape et al . 2006a). In seasonally frozen ground, especially in wetlands, a pulse of contamination is often released with each summer thaw (AMAP 1998; Snape et al . 2002). In these circumstances natural attenuation is likely not a satisfactory option. Simply excavating contaminants and removing them for off-site treatment may not be viable either, because the costs are often prohibitive and the environmental consequences of bulk extraction can equal or exceed the damage caused by the initial spill (Filler et al . 2006; Riser-Roberts 1998).

A four-phase conceptual model for supplier selection in agile supply chains (ASCs) is presented. The use of ASCs has become more common in today’s increasingly dynamic markets. However, supplier selection decisions are inherently more complex and difficult under the conditions of uncertainty and ambiguity created as supply chains form and re-form. The four phases of the model comprise Supplier selection preparation, Pre-classification, Final selection and Application feedback. It draws on a range of quantitative and qualitative techniques. These include application of the Dempster-Shafer and optimisation theories, radial basis function artificial neural networks (RBF-ANN), analytic network process-mixed integer multi-objective programming (ANP-MIMOP), Kraljic’s supplier classification matrix and the principles of continuous improvement. The resulting model offers a comprehensive and systematic approach to tackling this increasingly important task.

An international industry-government consortium is developing a fuelcell hybrid switcher locomotive for commercial railway applications and power-to-grid generation applications. The current phase of this on-going project addresses the practicalities of on-board hydrogen storage, fuelcell technology, and hybridity, all with an emphasis on commercially available products. Through practical evaluation using designs from Vehicle Projects’ Fuelcell-Powered Underground Mine Loader Project, the configuration of the fuelcell switcher locomotive changed from using metal-hydride hydrogen storage and a pure fuelcell power plant to using compressed hydrogen storage, a fuelcell-battery hybrid power plant, and fuelcell stack modules from Ballard Power Systems that have been extensively used in the Citaro bus program in Europe. The new overall design will now use a RailPower battery hybrid Green Goat™ as the locomotive platform. Keeping the existing lead-acid batteries, we will replace the 205 kW diesel gen-set with 225 kW of net fuelcell power, remove the diesel fuel tank, and place 14 compressed hydrogen cylinders, capable of storing 70 kg of hydrogen at 350 bar, on the roof. A detailed design with associated CAD models will allow a complete build of the fuelcell-battery hybrid switcher locomotive in the next funded phase.

It is increasingly clear that a wide range of stakeholders should be included in the problem formulation phase of research aimed at solving environmental problems; indeed the inclusion of stakeholders at this stage has been formalized as an integral part of ecological risk assessment. In this paper, we advocate the additional inclusion of stakeholders in the refinement of research methods and protocols and in the execution of the research, rather than just at the final communication and reporting phase. We use a large study of potential radionuclide levels in marine biota around Amchitka Island as a case study. Amchitka Island, in the Aleutian Island Chain of Alaska, was the site of three underground nuclear tests (1965-1971). The overall objective of the biological component of the study was to collect a range of marine biota for radionuclide analysis that could provide data for assessing current food safety and provide a baseline for developing a plan to monitor human and ecosystem health in perpetuity. Stakeholders, including regulators (State of Alaska), resource trustees (US Fish and Wildlife Service, State of Alaska), representatives of the Aleut and Pribilof Island communities, the Department of Energy (DOE), and others, were essential for plan development. While these stakeholders were included in the initial problem formulation and approved science plan, we also included them in the refinement of protocols, selection of bioindicators, selection of a reference site, choice of methods of collection, and in the execution of the study itself. Meetings with stakeholders resulted in adding (or deleting) bioindicator species and tissues, prioritizing target species, refining sampling methods, and recruiting collection personnel. Some species were added because they were important subsistence foods for the Aleuts, and others were added because they were ecological equivalents to replace species deleted because of low population numbers. Two major refinements that changed the research thrust were (1) the inclusion of Aleut hunters and fishers on the biological expedition itself to ensure that subsistence foods and methods were represented, and (2) the addition of a fisheries biologist on a NOAA research trawler to allow sampling of commercial fishes. Although the original research design called for the collection of biota by Aleut subsistence fishermen, and by a commercial fishing boat, the research was modified with continued stakeholder input to actually include Aleuts and a fisheries biologist on the expeditions to ensure their representation. The inclusion of stakeholders during the development of protocols and the research itself improved the overall quality of the investigation, while making it more relevant to the interested and affected parties. Final responsibility for the design and execution of the research and radionuclide analysis rested with the researchers, but the process of stakeholder inclusion made the research more valuable as a source of credible information and for public policy decisions.