Search

This comparison of five power plants in West Texas is intended to provide various decision-makers and stakeholders with a holistic picture of the life-cycle environmental impacts associated with these power plants. A key contribution of this analysis is that we assumed all power plants generate the same amount of electricity over a 30-year life, taking a 500 MW combined-cycle gas turbine (CCGT) plant as a benchmark. Also, in two cases, we added battery storage to wind and solar PV facilities to render them nearly as dispatchable as the CCGT. We included the entire supply chain supporting electricity generation, which encompassed raw material sourcing, processing, manufacturing, operations, and product end of life, also called "cradle to grave". We report on 18 environmental impacts using ReCiPe midpoint (H) impact assessment. The supply chains are global, and impacts are felt differently by host communities across the world. The results can help stakeholders identify hotspots across numerous supply chains with the highest environmental impacts. We discuss some remedial measures and challenges to inform future analysis by the research community. [ABSTRACT FROM AUTHOR]

As more pressure is exerted onto water sources, hydrologic systems may be altered in ways that are difficult to predict. In Texas, water deficits can become widespread as sources are strained beyond capacity. For smaller communities, such as Boerne, Texas, water management and planning is a way to prepare. The supply-demand water balance in Boerne is conceptualized through causal loop diagrams and system dynamics modeling. Through stakeholder engagement, xeriscaping, rainwater harvesting, and smart meters were chosen as interventions, each varied in adoption levels. The resulting 125 combinations were analyzed under three scenarios: a base case assuming maximum supply of water is firm, and two responses to a meteorological drought. Results show that the city can effectively forestall a deficit. Different combinations of adoptions can achieve the same goal, giving the city optionality in choosing strategies that are best suited for its needs and constraints. Rainwater harvesting was found to be the dominant intervention influencing demand, but its influence is reduced in the two drought scenarios. Xeriscaping was the second most influential intervention and smart meters for irrigation had no effect on demand. The approach used in this study highlights the interdependency between community adoption of conservation strategies and the importance of considering these relationships using systems modeling. [ABSTRACT FROM AUTHOR]

Projecting landscape impacts from energy development is essential to land management decisions. We forecast landscape alteration resulting from oil and gas well-pad construction across the economically important Permian Basin of Texas and New Mexico, USA, by projecting current landscape trends through 2050. We modeled three landscape-impact scenarios (low, medium, and high) using recent (2008–2017) trends in well-pad construction and energy production. The results of low-, medium-, and high-impact scenarios suggest that ~60,000, ~180,000, and ~430,000 new well pads could be constructed, potentially causing ~1000, ~2800, and ~6700 km2 of new direct landscape alteration. Almost two-thirds of all new well pads will be constructed within the geologic boundaries of the Delaware and Midland Basins. This translates into a 40, 120, and 300% increase in direct landscape alteration compared with direct alteration from existing well pads. We found that indirect effects (from edges) could increase by twofold, and that the ratio between indirect and direct alteration could decline by half as alteration intensifies and overlaps with existing alteration. The Chihuahuan Desert occupies the largest portion of the study area, and is projected to experience the largest area of alteration from future well-pad construction in the Permian Basin; the degree of direct alteration could increase by 70, 200, and 500% in this desert region, under low-, medium-, and high-impact scenarios. These scenarios can be used to design proactive conservation strategies to reduce landscape impacts from future oil and gas development. [ABSTRACT FROM AUTHOR]

Adequate native grass seed supply is a fundamental requirement for restoring disturbances associated with oil and gas production in West Texas. Knowing the amount and cost of native seed needed would be useful to oil and gas operators, seed producers, and conservation planners. We used projections of potential land impacts from oil and gas development, typical seeding rates, and current market prices to estimate the native grass seed supplies necessary and seed cost for low, medium, and high potential land-alteration scenarios. We estimate that at least 1.0% of the land area in the region has already been altered by oil and gas production, and that an additional 0.6–4.0% will be impacted by oil and gas pad or pipeline construction by 2050. Native seed supply between 112,000–600,000 kg (247,000–1,330,000 lbs.) of pure live seed (PLS) of native grasses valued between US $10–57 million will be needed for restoration to occur on all sites. These estimates provide targets for collaborative efforts focused on developing restoration seed source capacity through partnerships between seed source developers, the seed-production industry, practitioners, and energy producers. Our estimates also illustrate potential cost-savings for energy developers if land impacts can be minimized. [ABSTRACT FROM AUTHOR]

The increasing trend on water use for hydraulic fracturing (HF) in multiple plays across the U.S. has raised the need to improve the HF water management model. Such approaches require good-quality datasets, particularly in water-stressed regions. In this work, we presented a QA/QC framework for HF data using an outlier detection methodology based on five univariate techniques: two interquartile ranges at 95 and 90% (PCTL95, PCTL90), the median absolute deviation (MAD) and Z score with thresholds of two and three times the standard deviation (2STD, 3STD). The cleaning techniques were tested using multiple variables from two data sources centered on the Eagle Ford play (EFP), Texas, for the period 2011–2017. Results suggest that the PCTL95 and MAD techniques are the best choices to remove long-tailed statistical distributions of different variables, classifying the minimum number of records as outliers. Overall, outliers represent 13–23% of the total HF water volume in the EFP. In addition, outliers highly impacted minimum and maximum HF water use values (min–max range of 0–47 m3/m and 5.3–24.6 m3/m of frac length, before and after the outlier removal process, respectively), that are frequently used as a proxy to develop future water–energy scenarios in early-stage plays. The data and framework presented here can be extended to other plays to improve water footprint estimates with similar conditions. [ABSTRACT FROM AUTHOR]

Water resources development and landscape alteration exert marked impacts on water-cycle dynamics, including areas subjected to hydraulic fracturing (HF) for exploitation of unconventional oil and gas resources found in shale or tight sandstones. Here we apply a conceptual framework for linking baseflow analysis to changes in water demands from different sectors (e.g. oil/gas extraction, irrigation, and municipal consumption) and climatic variability in the semiarid Eagle Ford play in Texas, USA. We hypothesize that, in water-limited regions, baseflow ( Q b ) changes are partly due (along with climate variability) to groundwater abstraction. For a more realistic assessment, the analysis was conducted in two different sets of unregulated catchments, located outside and inside the Eagle Ford play. Three periods were considered in the analysis related to HF activities: pre-development (1980–2000), moderate (2001–2008) and intensive (2009–2015) periods. Results indicate that in the Eagle Ford play region, temporal changes in baseflow cannot be directly related to the increase in hydraulic fracturing. Instead, substantial baseflow declines during the intensive period of hydraulic fracturing represent the aggregated effects from the combination of: (1) a historical exceptional drought during 2011–2012; (2) increased groundwater-based irrigation; and (3) an intensive hydraulic fracturing activity. [ABSTRACT FROM AUTHOR]

Large-scale U.S. dependence on thermoelectric (steam electric) generation requiring water for cooling underscores the need to understand controls on this water use. The study objective was to quantify water consumption and withdrawal for thermoelectric generation, identifying controls, using Texas as a case study. Water consumption for thermoelectricity in Texas in 2010 totaled ∼0.43 million acre feet (maf; 0.53 km³), accounting for ∼4% of total state water consumption. High water withdrawals (26.2 maf, 32.3 km³) mostly reflect circulation between ponds and power plants, with only two-thirds of this water required for cooling. Controls on water consumption include (1) generator technology/thermal efficiency and (2) cooling system, resulting in statewide consumption intensity for natural gas combined cycle generators with mostly cooling towers (0.19 gal/kWh) being 63% lower than that of traditional coal, nuclear, or natural gas steam turbine generators with mostly cooling ponds (0.52 gal/kWh). The primary control on water withdrawals is cooling system, with ∼2 orders of magnitude lower withdrawals for cooling towers relative to once-through ponds statewide. Increases in natural gas combined cycle plants with cooling towers in response to high production of low-cost natural gas has greatly reduced water demand for thermoelectric cooling since 2000. [ABSTRACT FROM AUTHOR]

Examines efforts to renew medical negligence claims provisions under Article 4590i in the 1977 Medical Liability and Insurance Improvement Act (MLIIA) in Texas. Illustration of the common law system at work under the article; Limitations detailed in the article's provisions; Disputes on eliminating the discovery rule.

Hydraulic fracturing (HF) operations have transformed the unconventional energy industry, leading to a global increase in hydrocarbon production. Despite this, only the US, China, Canada and Argentina currently dominate production of unconventional resources, with the majority of shale basins globally remaining unprofitable to develop. An important gap in current water-energy nexus research, which this study addresses, is the assessment of potential water use to satisfy HF procedures in emergent plays. This work presents a screening tool for assessing first-order estimates of water impacts in undeveloped shale plays, testing the approach in the transboundary Eagle Ford (EF) play in northeast Mexico. We couple surface water and groundwater stress indicators derived from global hydrological variables to depict a baseline water stress index. Relative water stress is mapped for proposed blocks to be leased by the Mexican government in the future. We simulate four HF scenarios to assess new total water stress indicators for each block, considering shale production schemes using representative well drilling density (well lateral length(s) per unit area) and HF water intensity (HF water volume per unit lateral length) from existing EF development in Texas. Results suggest that the most feasible management scenario would consider the drilling of ∼1360 new unconventional wells/yr with projected HF water use of ∼57 Mm 3 /yr (0.7% of the total water withdrawals). The remaining scenarios will largely affect groundwater resources. Though applied to the EF in Mexico, this screening tool can assess water use constraints in emerging unconventional plays globally., (Copyright © 2019 Elsevier Ltd. All rights reserved.)