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At least 703 records · Page 39
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

Continued emissions of carbon tetrachloride from the United States nearly two decades after its phaseout for dispersive uses

National-scale emissions of carbon tetrachloride (CCl 4 ) are derived based on inverse modeling of atmospheric observations at multiple sites across the United States from the National Oceanic and Atmospheric Administration's flask air sampling network. We estimate an annual average US emission of 4.0 (2.0-6.5) Gg CCl 4 y -1 during 2008- 2012, which is almost two orders of magnitude larger than reported to the US Environmental Protection Agency (EPA) Toxics Release Inventory (TRI) (mean of 0.06 Gg y -1 ) but only 8% (3-22%) of global CCl 4 emissions during these years. Emissive regions identified by the observations and consistently shown in all inversion results include the Gulf Coast states, the San Francisco Bay Area in California, and the Denver area in Colorado. Both the observation-derived emissions and the US EPA TRI identified Texas and Louisiana as the largest contributors, accounting for one- to two-thirds of the US national total CCl 4 emission during 2008-2012. These results are qualitatively consistent with multiple aircraft and ship surveys conducted in earlier years, which suggested significant enhancements in atmospheric mole fractions measured near Houston and surrounding areas. Furthermore, the emission distribution derived for CCl 4 throughout the United States is more consistent with the distribution of industrial activities included in the TRI than with the distribution of other potential CCl 4 sources such as uncapped landfills or activities related to population density (e.g., use of chlorine-containing bleach).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Spatial-Temporal Analysis of PM 2.5 and NO 2 Concentrations Collected Using Low-Cost Sensors in Peñuelas, Puerto Rico

The U.S. Environmental Protection Agency (EPA) is involved in the discovery, evaluation, and application of low-cost air quality (AQ) sensors to support citizen scientists by directly engaging with them in the pursuit of community-based interests. The emergence of low-cost (<$2500) sensors have allowed a wide range of stakeholders to better understand local AQ conditions. Here we present results from the deployment of the EPA developed Citizen Science Air Monitor (CSAM) used to conduct approximately five months (October 2016–February 2017) of intensive AQ monitoring in an area of Puerto Rico (Tallaboa-Encarnación, Peñuelas) with little historical data on pollutant spatial variability. The CSAMs were constructed by combining low-cost particulate matter size fraction 2.5 micron (PM 2.5 ) and nitrogen dioxide (NO 2 ) sensors and distributed across eight locations with four collocated weather stations to measure local meteorological parameters. During this deployment 1 h average concentrations of PM 2.5 and NO 2 ranged between 0.3 to 33.6 µg/m 3 and 1.3 to 50.6 ppb, respectively. Peak concentrations were observed for both PM 2.5 and NO 2 when conditions were dominated by coastal-originated winds. These results advanced the community’s understanding of pollutant concentrations and trends while improving our understanding of the limitations and necessary procedures to properly interpret measurements produced by low-cost sensors.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Technoeconomic Optimization of Waste Heat Driven Forward Osmosis for Flue Gas Desulfurization Wastewater Treatment

With the Environmental Protection Agency’s recent Effluent Limitation Guidelines for Steam Electric Generators, power plants are having to install and operate new wastewater technologies. Many plants are evaluating desalination technologies as possible compliance options. However, the desalination technologies under review that can reduce wastewater volume or treat to a zero-liquid discharges standard have a significant energy penalty to the plant. Waste heat, available from the exhaust gas or cooling water from coal-fired power plants, offers an opportunity to drive wastewater treatment using thermal desalination technologies. One such technology is forward osmosis (FO). Forward osmosis utilizes an osmotic pressure gradient to passively pull water from a saline or wastewater stream across a semi-permeable membrane and into a more concentrated draw solution. This diluted draw solution is then fed into a distillation column, where the addition of low temperature waste heat can drive the separation to produce a reconcentrated draw solution and treated water for internal plant reuse. The use of low-temperature waste heat decouples water treatment from electricity production and eliminates the link between reducing water pollution and increasing air emissions from auxiliary electricity generation. In order to evaluate the feasibility of waste heat driven FO, we first build a model of an FO system for flue gas desulfurization (FGD) wastewater treatment at coal-fired power plants. This model includes the FO membrane module, the distillation column for draw solution recovery, and waste heat recovery from the exhaust gas. We then add a costing model to account for capital and operating costs of the forward osmosis system. We use this techno-economic model to optimize waste heat driven FO for the treatment of FGD wastewater. We apply this model to three case studies: the National Energy Technology Laboratory (NETL) 550 MW model coal fired power plant without carbon capture and sequestration, the NETL 550 MW model coal fired power plant with carbon capture and sequestration, and Plant Bowen in Eularhee, Georgia. For each case, we identify the design that minimizes the cost of wastewater treatment given the safely recoverable waste heat. We benchmark the cost minimum waste-heat forward osmosis solutions to two conventional options that rely on electricity, reverse osmosis and mechanical vapor recompression. Furthermore, we quantify the environmental damages from the emissions of carbon dioxide and criteria air pollutants for each treatment option. With this information we can assess the trade-offs between treatment costs, energy consumption, and air emissions between the treatment options.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2017

Evaluation of phenotype stability and ecological risk of a genetically engineered alga in open pond production

Genetically engineered (GE) algae offer the promise of producing food, fuel, and other valuable products with reduced requirements for land and fresh water. While the gains in productivity measured in GE terrestrial crops are predicted to be mirrored in GE algae, the stability of phenotypes and ecological risks posed by GE algae in large-scale outdoor cultivation remain unknown. In this paper, we describe the first US Environmental Protection Agency (EPA)-sanctioned experiment aimed at understanding how GE algae perform in outdoor cultivation. Acutodesmus dimorphus was genetically engineered by the addition of two genes, one for enhanced fatty acid biosynthesis, and one for recombinant green fluorescence protein (GFP) expression; both the genes and their associated phenotypes were maintained during fifty days of outdoor cultivation. We also observed that while the GE algae dispersed from the cultivation ponds, colonization of the trap ponds by the GE strain declined rapidly with increasing distance from the source cultivation ponds. In contrast, many species of indigenous algae were found in every trap pond within a few days of starting the experiment. When inoculated in water from five local lakes, the GE algae's effect on biodiversity, species composition, and biomass of native algae was indiscernible from those of the wild-type (wt) progenitor algae, and neither the GE nor wt algae were able to outcompete native strains. We conclude that GE algae can be successfully cultivated outdoors while maintaining GE traits, and that for the specific GE algal strain tested here they did not outcompete or adversely impact native algae populations when grown in water taken from local lakes. Finally, this study provides an initial evaluation of GE algae in outdoor cultivation and a framework to evaluate GE algae risks associated with outdoor GE algae production.

09 BIOMASS FUELS↗
DOE OSTI2016

Implementation of Enhanced Attenuation at the DOE Mound Site OU-1 Landfill: Accelerating Progress and Reducing Costs

At the US Department of Energy (DOE), Office of Legacy Management, Mound, Ohio, Site, chlorinated organic contaminants (cVOCs) originating from the former solid-waste landfill have impacted groundwater in Operable Unit 1 (OU-1). The baseline groundwater remedy was groundwater pump and treat (P&T). Since the source materials have been removed from the landfill, the Mound core team, which consists of DOE, US Environmental Protection Agency (US EPA), Ohio EPA, and other stakeholders, is assessing the feasibility of switching from the active P&T remedy to a passive attenuation-based remedy. Toward this end, an enhanced attenuation (EA) strategy based on the creation of structured geochemical zones was developed. This EA strategy addresses the residual areas of elevated cVOCs in soil and groundwater while minimizing the rebound of groundwater concentrations above regulatory targets (e.g., maximum contaminant levels [MCLs]) and avoiding plume expansion while the P&T system is turned off. The EA strategy has improved confidence and reduced risk on the OU-1 groundwater transition path to monitored natural attenuation (MNA). To better evaluate the EA strategy, DOE is conducting a field demonstration to evaluate the use of edible oils to enhance the natural attenuation processes. The field demonstration is designed to determine whether structured geochemical zones can be established that expedite the attenuation of cVOCs in the OU-1 groundwater. The EA approach at OU-1 was designed based on “structured geochemical zones” and relies on groundwater flow through a succession of anaerobic and aerobic zones. The anaerobic zones stimulate relatively rapid degradation of the original solvent source compounds (e.g., cVOCs such as tetrachloroethene [PCE] and trichloroethene [TCE]). The surrounding aerobic areas encourage relatively rapid degradation of daughter products (such as dichloroethene [DCE] and vinyl chloride [VC]) as well as enhanced cometabolism of TCE resulting from the utilization of methane and other reduced hydrocarbons that are formed and released from the anaerobic zones.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2018

Summary of Observations from the 2017 Federal Radiological Monitoring and Assessment Center (FRMAC) Laboratory Analysis Training and Capstone Event

On August 15th thru 17th, 2017 the Federal Radiological Monitoring and Assessment Center (FRMAC) Laboratory Analysis division, the FRMAC Fly Away Laboratory (FAL), the FRMAC Assessment division, and the Mobile Environmental Response Laboratory (MERL) held a training and capstone event for staff from the Environmental Protection Agency (EPA), Remote Sensing Laboratory (RSL), Lawrence Livermore National Laboratory (LLNL), and Sandia National Laboratories (SNL). LAB-100, "Sample Control Training", LAB-200 "QA Specialist Training", and LAB-300 "Laboratory Analysis Manager Training" was given the first two days of the event. The purpose of the training and capstone event was to meet training requirements for billeted FRMAC Lab Analysis staff from RSL, LLNL, and SNL as well as raise awareness of the FRMAC Lab Analysis process with EPA staff as part of a Federal Emergency Management Agency — Nuclear Incident Response Team (FEMA-NIRT) laboratory standardization project. An objective of the standardization project was to help improve the transition of operations from DOE to EPA during a response. To do this effectively, detailed knowledge of the FRMAC Lab Analysis process by the EPA is needed. This training provided a good opportunity for this knowledge transfer. A capstone was held after the two-day training event to allow participants to practice the skills they learned in a realistic scenario. A scenario that was previously developed for a quarterly Consequence Management drill (i.e. Dark Phoenix) was used as the basis for the capstone, with laboratory analysis focused injects used to drive the exercise play. Each position within the FRMAC Lab Analysis Division exercised to specific objectives and helped to uncover gaps in the established processes. The lessons learned during this capstone are broken out in the following categories: Sample Control, In-Situ Gamma Spectroscopy, Analysis Request Forms (ARF), Shipping, QA/QC, Fly Away Laboratory (FAL), and Management.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

A risk-based approach to evaluating the Area of Review and leakage risks at CO 2 storage sites

The U.S. Environmental Protection Agency’s Class VI regulations for underground carbon dioxide (CO 2 ) injection require owners and operators of storage projects to identify (1) an Area of Review (AoR) that represents the region that may be affected by the injection of CO 2 , and (2) leakage risks that might impact the quality of underground sources of drinking water (USDWs). This article describes how such risks can be determined by accounting for the physical and chemical properties of all components of a CO 2 storage site using elements of the National Risk Assessment Partnership Integrated Assessment Model for Carbon Storage (NRAP-IAM-CS). For this work we used practical data from three sites that are part of two CarbonSAFE (Carbon Storage Assurance Facility Enterprise) projects to demonstrate application of the NRAP-IAM-CS toolset to determine project risk areas. NRAP-IAM-CS was used to estimate the project risk area that could represent the AoR and the impact of leakage through legacy wells to overlying drinking waters at these candidate CO 2 storage sites. Our study shows that risk to USDWs is minimal despite (1) the presence of multiple legacy wells at these sites where the AoR approximates the maximum extent of injected CO 2 or (2) the presence of a much larger AoR approximating the pressure front caused by the injection of CO 2 .

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Data Report for Monitoring at Six West Virginia Marcellus Shale Development Sites using NETL’s Mobile Air Monitoring Laboratory (July–November 2012)

The West Virginia Department of Environmental Protection’s Office of Oil and Gas was directed according to the Natural Gas Horizontal Well Control Act of December 14, 2011 (West Virginia Code §22-6A) to conduct studies of horizontal well drilling activities related to air quality. The planned study, “Noise, Light, Dust, Volatile Organic Compounds Related to Well Location Restrictions,” required determination of the effectiveness of a 625 ft minimum set-back from the center of the pad of a horizontal well drilling site to the nearest occupied dwelling. An investigation was conducted at seven drilling sites by West Virginia University (WVU) and the National Energy Technology Laboratory (NETL) to collect data on dust, hydrocarbon compounds and on noise, radiation, and light levels. NETL’s role in this study was to collect measurements of ambient pollutant concentrations at six of the seven selected sites using NETL’s Mobile Air Monitoring Laboratory. The trailer-based laboratory was situated a distance of 492–1,312 ft from each well pad, on which activities included well pad construction, vertical drilling, horizontal drilling, hydraulic fracturing, and flaring, with the objective of evaluating the air quality impact of each activity for 1–4 weeks per site. Measured pollutants included volatile organic compounds (VOCs), coarse and fine particulate matter (PM 10 and PM 2.5 , respectively), ozone, methane (CH 4 ), carbon dioxide (CO 2 ), carbon isotopes of CH 4 and CO 2 , organic carbon (OC), elemental carbon (EC), oxides of nitrogen (NOx), and sulfur dioxide (SO 2 ).

03 NATURAL GAS↗
DOE OSTI2022

Oak Ridge National Laboratory EPA Approval Letters and Historical Documentation for a Modification in Applying 40 CFR Part 61 Appendix D

Appendix D of Title 40 Part 61, “Methods for Estimating Radionuclide Emissions,” of the Code of Federal Regulations (CFR) provides a procedure that US Department of Energy (DOE) facility owners and operators can use to estimate radionuclide emissions to the atmosphere for dose calculations instead of measuring emissions for minor sources under 40 CFR Part 61, Subpart H, “National Emission Standards for Emissions of Radionuclides Other than Radon from Department of Energy Facilities.” The procedure assumes that any radioactive material heated above 100°C is completely vaporized and emitted to the atmosphere. In 1991, the DOE Oak Ridge Reservation (DOE-ORR) requested approval to use different release fractions (RFs) for uranium because of its high melting and boiling points (1,132°C and 3,818°C, respectively). In response to the request, Environmental Protection Agency (EPA) Region IV approved the use of modified RFs for elemental uranium provided no reaction had taken place to alter its chemical form. In 2015, DOE-ORR requested approval to use different RFs for radioactive tungsten, also because of its high melting and boiling points (3,410°C and 5,660°C, respectively). EPA Region IV approved the use of modified RFs for heated radioactive tungsten metal. In accordance with the two precedents set for heating uranium and radioactive tungsten metals, in 2016, DOE-ORR requested approval to use modified RFs in similar fashion for other radioactive solid metals and compounds with melting and boiling points above 500°C that might be heated above 100°C in future research projects and experiments, and again, the EPA Region IV granted approval to use modified RFs for the list of compounds. This document contains the EPA approval letters and historical documentation used in the process to obtain approval for the use of alternative Appendix D emission factors. The approval to DOE-ORR allows modifying the existing regulatory RFs to 1 when radioactive solid metals and compounds are heated to temperatures greater than or equal to the boiling point of the solid, to 10 -3 when radioactive solid metals and compounds are heated to temperatures greater than or equal to 90% of the melting point and less than the boiling point of the solid, and to 10 -6 when radioactive solid materials are heated to temperatures above ambient air temperature but below 90% of the melting point of the solid.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Identifying priority ecosystem services in tidal wetland restoration

Classification systems can be an important tool for identifying and quantifying the importance of relationships, assessing spatial patterns in a standardized way, and forecasting alternative decision scenarios to characterize the potential benefits (e.g., ecosystem services) from ecosystem restoration that improve human health and well-being. We present a top-down approach that systematically leverages ecosystem services classification systems to identify potential services relevant for ecosystem restoration decisions. We demonstrate this approach using the U.S. Environmental Protection Agency’s National Ecosystem Service Classification System Plus (NESCS Plus) to identify those ecosystem services that are relevant to restoration of tidal wetlands. We selected tidal wetland management documents from federal agencies, state agencies, wetland conservation organizations, and land stewards across three regions of the continental United States (northern Gulf of Mexico, Mid-Atlantic, and Pacific Northwest) to examine regional and organizational differences in identified potential benefits of tidal wetland restoration activities and the potential user groups who may benefit. We used an automated document analysis to quantify the frequencies at which different wetland types were mentioned in the management documents along with their associated beneficiary groups and the ecological end products (EEPs) those beneficiaries care about, as defined by NESCS Plus. Results showed that a top combination across all three regions, all four organizations, and all four tidal wetland types was the EEP naturalness paired with the beneficiary people who care (existence). Overall, the Mid-Atlantic region and the land steward organizations mentioned ecosystem services more than the others, and EEPs were mentioned in combination with tidal wetlands as a high-level, more general category than the other more specific tidal wetland types. Certain regional and organizations differences were statistically significant. Those results may be useful in identifying ecosystem services-related goals for tidal wetland restoration. This approach for identifying and comparing ecosystem service priorities is broadly transferrable to other ecosystems or decision-making contexts.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

Simulation of carbon dioxide injection at the FutureGen2.0 site: Class VI permit model and local sensitivity analysis

Numerical simulation was conducted to evaluate supercritical CO 2 (scCO 2 ) storage in the Mt. Simon sandstone at the FutureGen 2.0 site in Morgan County, Illinois. The simulations illustrate the recent modeling effort conducted to successfully obtain a Class VI permit under the Underground Injection Control Program of the U.S. Environmental Protection Agency. The scCO2 was injected into a highly stratified reservoir, distributed among four lateral wells. Results show that each of the multiple reservoir layers with low permeability traps a fraction of the scCO 2 beneath it so that the injected scCO 2 does not reach the top of the reservoir by the end of the simulation period. Hence, all of the injected scCO 2 is considered to be safely trapped by the stratified structure within the reservoir. A local sensitivity analysis (LSA) was conducted for injectivity and plume size at the end of the 20 year injection period. The LSA indicates that the imposed initial conditions and the hydraulic properties of the injection layer contribute the most to the sensitivity. Overall, the simulation outputs are very sensitive to only a small fraction of the inputs. However, the parameters that are important for controlling CO 2 injectivity are not the same as those controlling the plume area. The three most sensitive inputs for injectivity are the horizontal permeability and the residual aqueous saturation of the injection layer, and the initial fracture-pressure gradient. For the plume area, the most sensitive inputs are the horizontal permeability of the injection layer and the residual aqueous saturation of the two adjacent layers above the injection layer. Furthermore, the advantages of requiring just a single set of simulation results, scalability to the proper parameter errors, and straightforward calculation of the composite sensitivities make the proposed analysis attractive for guiding site characterization, injection well design, estimating AoR uncertainty and, and monitoring network design.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

RCRA Part B Permit Application Nevada National Security Site (NNSS) for Waste Management Activities at the NNSS Hazardous Waste Storage Unit (HWSU)

This volume of the permit application by the DOE’s National Nuclear Security Administration Nevada Field Office (NNSA/NFO) to the Nevada Division of Environmental Protection (NDEP) focuses on the Area 5 Hazardous Waste Storage Unit (HWSU). The HWSU was established to support testing, research, and remediation activities at the Nevada National Security Site (NNSS), a large-quantity generator of hazardous waste. The HWSU, located adjacent to the Area 5 Radioactive Waste Management Complex (RWMC), is a prefabricated, rigid steel-framed, roofed shelter used to store hazardous nonradioactive waste generated on the NNSS. No offsite-generated wastes are managed at the HWSU. Waste managed at the HWSU includes the following: Flammables/Combustibles, Acid Corrosives, Alkali Corrosives, Oxidizers/Reactives, Toxics/Poisons, and Other Regulated Materials (ORMs). A list of regulated waste codes accepted for storage at the HWSU is provided in this volume. Hazardous wastes are stored at the HWSU in containers that are compliant with U.S. Department of Transportation (DOT) regulations and compatible with the stored waste. Waste packages (e.g., drums) without inner closed containers of waste remain closed except during inspection or sampling. Transfer of uncontainerized waste between waste packages at the HWSU is prohibited. Closed inner containers may be transferred or consolidated into larger waste packages, and small closed containers may be placed into larger containers. Containers are stored on secondary containment pallets, and the unit is inspected monthly. For safety and security reasons, some of the contents of the full application are not available for public viewing. This public version of the application contains most, but not all, of the contents as submitted to the regulatory agencies.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Illinois Storage Corridor - CarbonSAFE Phase III: Policy, Regulatory, Legal and Permitting Characteristics; Subtask 5.5

The Illinois Storage Corridor (ISC) project aims to advance the commercial development and implementation of carbon capture and storage (CCS) technologies within a region in Illinois of suitable geology for carbon dioxide (CO 2 ) storage in deep saline aquifers. The project partners have annual emissions greater than 6.5 million tonnes per year; storage hubs are being explored at two sites—one near the One Earth Energy facility in east-central Illinois, and one near the Prairie State Generating Company campus in southwest Illinois. To implement the technology, legal, policy, and economic considerations must be explored. The United States Environmental Protection Agency (US EPA) administers the Underground Injection Control (UIC) program and is responsible for issuing Class VI permits to construct and operate CO 2 injection wells, i.e., a UIC Class VI well permit is required to inject CO 2 into the subsurface for geologic sequestration. The largest consideration of the Class VI well requirements is to protect underground sources of drinking water (USDWs). Additionally discussed are considerations for Class VI permits relating to public engagement. Besides permitting, property rights to storage sites, subsurface pore spaces, and areas for pipeline transportation must be secured. Pore space rights is still a novel concept being explored and not yet addressed by the Illinois legislature. It is believed that surface property rights are required for the subsurface pore space below, so long as there is not a separated mineral estate in the subsurface. Illinois legislature has addressed securing rights-of-way for CO 2 transportation, allowing for easements and the exercise of eminent domain to secure such rights. Economically, the incentives for CCS are ever-expanding. Recently, the federal government broadened the availability and increased the dollar-amounts for the § 45Q tax credits for geological storage of carbon oxides. Congress has also authorized the Advanced Industrial Facilities Development Program which allocates billions of dollars in funds to installing technology at industrial facilities to reduce greenhouse gas emissions. On the state level, Illinois has had its own incentives for CCS projects since 2009 and expanded its emission-related goals again in 2021. The law enacted in 2021 specifically creates a commission to explore implementing CCS at Prairie State Generating Company, a partner on the Illinois Storage Corridor project.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Bishop Paiute Single Family Solar Home Project: Phase 4 (Final Technical Report)

The Bishop Paiute Tribe is committed to energy efficiency, renewable energy, and environmental protection and has a vision to install solar energy systems on all buildings on the Reservation where technically feasible. Through completion of the Bishop Paiute Tribe Residential Solar Program – Phase 4, Bishop Paiute Tribe continued its successful model partnering with non-profit solar installer GRID Alternatives to advance its vision and build energy self-sufficiency on the Bishop Paiute Reservation. The Bishop Paiute Tribe Residential Solar Program – Phase IV deployed 67 kW-AC of new clean, renewable energy through grid-tied, net-metered rooftop solar electric systems installed on a total of 20 (one more than the planned 19) existing owner-occupied, single-family homes for low-income families on the Reservation. This represents nearly 14% of the Reservation’s total “unsolarized” homes. These systems were provided at no cost to the homeowners, who will also receive energy efficiency education to further reduce energy consumption and lower electric bills. GRID led a solar installation for three (3) of the homes where Tribal/community members, were given an opportunity in participating in on-the-roof trainings to gain new skills while installing solar for their low-income community members. Subcontractors through GRID Sub Contractor Partnership Program (GRID SPP) led solar installations for seventeen (17) of the homes. Each installation provided paid employment for a solar trainee trainees hired by the SPP subcontractors as entry level solar installers. It is estimated that the installed 67 kW-AC of solar will produce at least 120,000 kWh/year, displacing at least 30-75% of the 20 homes’ total electricity use for a combined system lifetime electricity cost savings for the low-income homeowners of about $\$$500,000. It is further estimated that the installed renewable energy systems installed will prevent greenhouse gases by about 1,000 tons, equivalent to planting approximately 25,000 trees. Following the successful completed installations, it is expected that the Reservation and surrounding communities will benefit from improved air quality via reduced wood stove use for heating. Cumulatively with other initiatives, the project will result in nearly 40% of the Reservation’s solarizable homes being solarized. Overall, the triple impact of the phase 4 of the Bishop Paiute Tribe Residential Solar Program – Phase 4 is: 1) affordable energy for low-income families; 2) on-site clean energy production, 3) hands on training and paid solar installation work for local tribal/community workers. These impacts will support and grow the Tribe’s energy, economic, environmental, and social self-sufficiency and sovereignty amongst the neediest on the Reservation.

14 SOLAR ENERGY↗
DOE OSTI2016

Geologic carbon sequestration injection wells in overpressured storage reservoirs: estimating area of review

The Area of Review (AoR) under the US Environmental Protection Agency's (EPA) Class VI CO 2 injection permit is defined as the region surrounding the geologic carbon sequestration (GCS) project where underground sources of drinking water (USDWs) may be endangered. Estimation of the AoR is based on the calculated reservoir pressurization due to CO 2 injection and the associated potential to lift saline water into potable groundwater aquifers through open flow paths (e.g. wells) assuming the system is hydrostatic. In cases where the storage reservoirs are not initially hydrostatic, and in particular where they are overpressured, AoR estimation methods need to be altered. Here in this paper, we present and apply an approach to evaluating potential endangerment of USDW based on comparing brine leakage through a hypothetical open flow path in a no-injection scenario and brine leakage in a CO 2 -injection scenario. We present six possible ways to normalize injection-related leakage relative to no-injection leakage. We calculate leakage using semi-analytical solutions for single-phase flow and model reservoir pressurization and flow up (single) leaky wells located progressively farther from the injection well. For an example case of relative overpressure and using an injection-rate-based approach, results show 50-60% larger open-well-leakage rates for wells located at 2 km and 10% increase for wells located at 10 km from the injection well relative to the no-injection case. If total brine leakage is considered, the results depend strongly on the assumed pre-injection to post-injection time frames and on the methods of normalization used to calculate incremental leakage.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Rogers Quarry Special Studies Report 2024

Rogers Quarry (RQ) has a history of elevated selenium (Se) concentrations in water and fish caused by inputs from the Y-12 National Security Complex Filled Coal Ash Pond (FCAP). Selenium is acutely toxic at high concentrations, and chronic toxicity occurs at low aqueous concentrations because Se bioaccumulates in fish tissues. The US Environmental Protection Agency (EPA) recently developed water quality criteria for Se that include fish tissue as well as aqueous Se concentrations. The water column concentration criterion is 1.5 µg L -1 for lentic ecosystems and 3.1 µg L -1 for lotic ecosystems. The fish tissue criteria include both an egg/ovary concentration (15.1 µg/g dry weight) and a concentration for whole-body (8.5 µg/g dry weight) or fish muscle (11.3 µg/g dry weight). The egg/ovary criterion supersedes the fillet and aqueous concentrations if measured because Se toxicity manifests via reproductive effects in birds and fish. It is maternally transferred through eggs, leading to teratogenicity (i.e., deformities, developmental effects) in young fish. Historical bioaccumulation data suggest that Se is likely the primary contaminant of concern in RQ, but more recent sampling shows that aqueous As concentrations have been elevated in upper McCoy Branch (MB) leading to RQ. More recently, Se concentrations in fish collected from upper MB were found to be above the tissue criterion for Se for whole-body fish. In FY 2019, actions were taken to deepen the constructed wetland just downstream of the FCAP to increase its ability to remove coal ash particulates from the water column before water enters MB. Sampling was conducted throughout MB in FY 2020-2024 to evaluate the effectiveness of the actions taken in the FCAP wetland and to measure Se concentrations in biota throughout the watershed. The methods and results from a water and fish field collection campaign in April 2024 are presented in this report.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

A multi-criteria land suitability assessment of field allocation decisions for switchgrass

With the goal of evaluating biomass resource availability in certain regions in the United States, the Department of Energy, Department of Agriculture, Environmental Protection Agency, national laboratories, and Forest Service research laboratories, together with academic and industry collaborators, performed a resource analysis study, 2016 Billion-Ton Report: Advancing Domestic Resources for a Thriving Bioeconomy, Volume 1: Economic Availability of Feedstocks, using POLYSYS model to estimate biomass potential. The study provided county- and state-level biomass potential projections, with biomass feedstock production estimates and suitability assessment of lands acreage likely to transition to energy crops. For this analysis, we estimate biomass supply by year 2028, more specifically, lands acreage transition to switchgrass in the Midwest of the United States, across 50 counties in 3 states (Nebraska, Kansas, and Colorado). We propose a multi-criteria site suitability framework, to determine the potential acreage and production for switchgrass, at the field level. Site selection criteria span agronomic and ecosystem services such as previous land cover, crop rotation, soil water holding capacity, crop productivity, field efficiency, topography, soil organic matter, soil leaching propensity, distance to surface water bodies, and soil erosivity. Efficient agricultural field selection for dedicated energy crops field allocation is critical to evaluate biomass resource availability, and it is our position that estimation at the field level would provide a more accurate and useful estimation to support an emerging bioeconomy. Using field suitability scores and county-level assessments, we model land allocation decision for energy crop in the future, estimating the spatial distribution of dynamics of energy crop adoption with priority to fields scoring the highest. Additionally, compared with POLYSYS results from the report mentioned above, our method shows good performance overall, with about 2% and 1.2% of difference in switchgrass acreage allocation and crop production, respectively.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Estimating the Effects of Soil Remediation on Children’s Blood Lead near a Former Lead Smelter in Omaha, Nebraska, USA

Lead exposures from legacy sources threaten children’s health. Soil in Omaha, Nebraska, was contaminated by emissions from a lead smelter and refinery. The U.S. Environmental Protection Agency excavated and replaced contaminated soil at the Omaha Lead Superfund Site between 1999 and 2016. The goal of this study was to assess the association of soil lead level (SLL) and soil remediation status with blood lead levels (BLLs) in children living near or on the site. We linked information on SLL at residential properties with children’s BLLs and assigned remediation status to children’s BLL measurements based on whether their measurements occurred during residence at remediated or unremediated properties. We examined the association of SLL and remediation status with elevated BLL (EBLL). We distinguished the roles of temporal trend and the intervention with time-by-intervention-status interaction contrasts. All analyses estimated odds ratios (ORs) with a generalized estimating equations approach to ensure robustness under the complex correlations among BLL measurements. All analyses controlled for relevant covariates including children’s characteristics. EBLL (> 5 μg/dL ) was associated with both residential SLL [e.g., OR=2.00; 95% confidence interval (CI): 1.83, 2.19; > 400–800 vs. ≤ 200 ppm] and neighborhood SLL [e.g., OR=1.85 (95% CI: 1.62, 2.11; > 400–800 vs. ≤ 200 ppm)] before remediation but only with neighborhood SLL after remediation. The odds of EBLL were higher before remediation [OR 1.52 (95% CI: 1.34, 1.72)]. Similarly, EBLL was positively associated with preremediation status in our interaction analysis [interaction OR=1.18 (95%CI: 1.02, 1.37)]. Residential and neighborhood SLLs were important predictors of EBLLs in children residing near or on this Superfund site. Neighborhood SLL remained a strong predictor following remediation. Our data analyses showed the benefit of soil remediation. Results from the interaction analyses should be interpreted cautiously due to imperfect correspondence of remediation times between remediation and comparison groups. https://doi.org/10.1289/EHP8657

54 ENVIRONMENTAL SCIENCES↗