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This study presents an effective approach to tackle the challenge of long-term monitoring of contaminated groundwater sites where remediation leaves residual contamination in the subsurface. Traditional long-term monitoring of contaminated groundwater sites focuses on measuring contaminant concentrations and is applicable to sites where contaminant mass is removed or degraded to a level below the regulatory standard. The traditional approach is less effective at sites where risk from metals or radionuclides continues to exist in the subsurface after remedial goals are achieved. We propose a long-term monitoring strategy for this type of waste site that focuses on measuring the hydrological and geochemical parameters that control attenuation or remobilization of contaminants while de-emphasizing contaminant-concentration measurements. We demonstrate how this approach would be more effective than traditional long-term monitoring, using a site in South Carolina, USA, where groundwater is contaminated by several radionuclides. A comprehensive enhanced attenuation remedy has been implemented at the site to minimize discharge of contamination to surface water. The immobilization of contaminants occurs in three locations by manipulation of hydrological and geochemical parameters, as well as by natural attenuation processes. Deployment of our proposed long-term monitoring strategy will combine subsurface and surface measurements using spectroscopic tools, geophysical tools, and sensors to monitor the parameters controlling contaminant attenuation. The advantage of this approach is that it will detect the potential for contaminant remobilization from engineered and natural attenuation zones, allowing potential adverse changes to be mitigated before contaminant attenuation is reversed.

Objective: This article presents a pilot study that employed a user-centered methodology for evaluating and quantifying neonatal intensive care unit (NICU) designs based on the needs of the primary users., Background: The design of NICUs has begun to shift from open-bay to single-family rooms. Both designs present unique advantages and challenges that impact babies, families, and caregivers., Methods: One NICU design was analyzed using the functional scenario (FS) analysis method. For the FS, users' needs were determined through literature review, interviews with NICU providers and parents, and a review of published design guidelines. Quantitative metrics were developed for each FS, so that characteristics of the NICU design could be analyzed to determine how successful they were in meeting the users' needs. The results were graphically represented to visualize the success and considerations of the design., Results: A total of 23 FSs and 61 spatial metrics were developed. FSs for babies focused on infection prevention, minimizing exposure to environmental stimuli, and supporting enriching care activities. FSs for family members focused on direct access to the baby, and privacy and adequate space for daily activities. FSs for providers and caregivers focused on infection prevention, care activities, care zones, and visibility., Conclusion: Using an FS approach highlights design characteristics in the NICU that need to be addressed during the design process to more successfully meet the needs of the different users. Additionally, using this approach can inform design professionals' decision-making by presenting them with the design characteristics that impact the needs of the user groups.

Objective: This comparative study of two adult neuro critical care units examined the impact of patient- and family-centered design on nurse-family interactions in a unit designed to increase family involvement., Background: A growing evidence base suggests that the built environment can facilitate the delivery of patient- and family-centered care (PFCC). However, few studies examine how the PFCC model impacts the delivery of care, specifically the role of design in nurse-family interactions in the adult intensive care unit (ICU) from the perspective of the bedside nurse., Methods: Two neuro ICUs with the same patient population and staff, but with different layouts, were compared. Structured observations were conducted to assess changes in the frequency, location, and content of interactions between the two units. Discussions with staff provided additional insights into nurse attitudes, perceptions, and experiences caring for families., Results: Nurses reported challenges balancing the needs of many stakeholders in a complex clinical environment, regardless of unit layout. However, differences in communication patterns between the clinician- and family-centered units were observed. More interactions were observed in nurse workstations in the PFCC unit, with most initiated by family. While the new unit was seen as more conducive to the delivery of PFCC, some nurses reported a loss of workspace control., Conclusions: Patient- and family-centered design created new spatial and temporal opportunities for nurse-family interactions in the adult ICU, thus supporting PFCC goals. However, greater exposure to unplanned family encounters may increase nurse stress without adequate spatial and organizational support., (© The Author(s) 2015.)

129 I is commonly either the top or among the top risk drivers, along with 99 Tc, at radiological waste disposal sites and contaminated groundwater sites where nuclear material fabrication or reprocessing has occurred. The risk stems largely from 129 I having a high toxicity, a high bioaccumulation factor (90% of all the body's iodine concentrates in the thyroid), a high inventory at source terms (due to its high fission yield), an extremely long half-life (16M years), and rapid mobility in the subsurface environment. Another important reason that 129 I is a key risk driver is that there is uncertainty regarding its biogeochemical fate and transport in the environment. We typically can define 129 I mass balance and flux at sites, but cannot predict accurately its response to changes in the environment. As a consequence of some of these characteristics, 129 I has a very low drinking water standard, which is set at 1 pCi/L, the lowest of all radionuclides in the Federal Register. Recently, significant advancements have been made in detecting iodine species at ambient groundwater concentrations, defining the nature of the organic matter and iodine bond, and quantifying the role of naturally occurring sediment microbes to promote iodine oxidation and reduction. These recent studies have led to a more mechanistic understanding of radioiodine biogeochemistry. The objective of this review is to describe these advances and to provide a state of the science of radioiodine biogeochemistry relevant to its fate and transport in the terrestrial environment and provide information useful for making decisions regarding the stewardship and remediation of 129 I contaminated sites. As part of this review, knowledge gaps were identified that would significantly advance the goals of basic and applied research programs for accelerating 129 I environmental remediation and reducing uncertainty associated with disposal of 129 I waste. Together the information gained from addressing these knowledge gaps will not alter the observation that 129 I is primarily mobile, but it will likely permit demonstration that the entire 129 I pool in the source term is not moving at the same rate and some may be tightly bound to the sediment, thereby smearing the modeled 129 I peak and reducing maximum calculated risk.

Acidic low-level waste radioactive waste solutions were discharged to three unlined seepage basins at the F-Area of the Department of Energy (DOE) Savannah River Site (SRS), South Carolina, USA, from 1955 through 1989. Despite many years of active remediation, the groundwater remains acidic and contaminated with significant levels of U(VI) and other radionuclides. Monitored Natural Attenuation (MNA) is a desired closure strategy for the site, based on the premise that regional flow of clean background groundwater will eventually neutralize the groundwater acidity, immobilizing U(VI) through adsorption. An in situ treatment system is currently in place to accelerate this in the downgradient portion of the plume and similar measures could be taken upgradient if necessary. Understanding the long-term pH and U(VI) adsorption behavior at the site is critical to assess feasibility of MNA along with the in-situ remediation treatments. This paper presents a reactive transport (RT) model and uncertainty quantification (UQ) analyses to explore key controls on the U(VI)-plume evolution and long-term mobility at this site. Two-dimensional numerical RT simulations are run including the saturated and unsaturated (vadose) zones, U(VI) and H(+) adsorption (surface complexation) onto sediments, dissolution and precipitation of Al and Fe minerals, and key hydrodynamic processes are considered. UQ techniques are applied using a new open-source tool that is part of the developing ASCEM reactive transport modeling and analysis framework to: (1) identify the complex physical and geochemical processes that control the U(VI) plume migration in the pH range where the plume is highly mobile, (2) evaluate those physical and geochemical parameters that are most controlling, and (3) predict the future plume evolution constrained by historical, chemical and hydrological data. The RT simulation results show a good agreement with the observed historical pH and concentrations of U(VI), nitrates and Al concentrations at multiple locations. Mineral dissolution and precipitation combined with adsorption reactions on goethite and kaolinite (the main minerals present with quartz) could buffer pH at the site for long periods of time. UQ analysis using the Morris one-at-a-time (OAT) method indicates that the model/parameter is most sensitive to the pH of the waste solution, discharge rates, and the reactive surface area available for adsorption. However, as a key finding, UQ analysis also indicates that this model (and parameters) sensitivity evolves in space and time, and its understanding could be crucial to assess the temporal efficiency of a remediation strategy in contaminated sites. Results also indicate that residual U(VI) and H(+) adsorbed in the vadose zone, as well as aquifer permeability, could have a significant impact on the acidic plume long-term mobility., (Copyright © 2013 Elsevier B.V. All rights reserved.)

At the Savannah River Site's F-Area, wastewaters containing radionuclides were disposed into seepage basins for decades. After closure and capping in 1991, the U.S. Department of Energy (DOE) has being monitoring and remediating the groundwater plume. Despite numerous studies of the plume, its persistence for over 20 years has not been well understood. To better understand the plume dynamics, a limited number of deep boreholes were drilled to determine the current plume characteristics. A mixing model was developed to predict plume tritium and nitrate concentrations. We found that the plume trailing edges have emerged for some contaminants, and that contaminant recharge from the basin's vadose zone is still important. The model's estimated time-dependent basin drainage rates combined with dilution from natural recharge successfully predicted plume tritium and nitrate concentrations. This new understanding of source zone influences can help guide science-based remediation, and improve predictions of the natural attenuation timeframes.

Field and laboratory studies were carried out to understand the cause for steady increases in (129)I concentrations emanating from radiological basins located on the Savannah River Site, South Carolina. The basins were closed in 1988 by adding limestone and slag and then capping with a low permeability engineered cover. Groundwater (129)I concentrations in a well near the basins in 1993 were 200 pCi L(-1) and are presently between 400 and 1000 pCi L(-1). Iodine speciation in the plume contained wide ranges of iodide, iodate, and organo-iodine concentrations. First-order calculations based on a basin sediment desorption study indicate that the modest increase of 0.7 pH units detected in the study site groundwater over the last 17 years since closure of the basins may be sufficient to produce the observed increased groundwater (129)I concentrations near the basins. Groundwater monitoring of the plume at the basins has shown that the migration of many of the high risk radionuclides originally present at this complex site has been attenuated. However, (129)I continues to leave the source at a rate that may have been exacerbated by the initial remediation efforts. This study underscores the importance of identifying the appropriate in situ stabilization technologies for all source contaminants, especially if their geochemical behaviors differ.