Environmental problems of sitting and operating desalination plants in the United States

Environmental problems of siting and operating desalination plants in the united states

The United States (US) energy system is a large water user, but the nature of that use is poorly understood. To support resource comanagement and fill this noted gap in the literature, this work presents detailed estimates for US-based water consumption and withdrawals for the US energy system as of 2014, including both intensity values and the first known estimate of total water consumption and withdrawal by the US energy system. We address 126 unit processes, many of which are new additions to the literature, differentiated among 17 fuel cycles, five life cycle stages, three water source categories, and four levels of water quality. Overall coverage is about 99% of commercially traded US primary energy consumption with detailed energy flows by unit process. Energy-related water consumption, or water removed from its source and not directly returned, accounts for about 10% of both total and freshwater US water consumption. Major consumers include biofuels (via irrigation), oil (via deep well injection, usually of nonfreshwater), and hydropower (via evaporation and seepage). The US energy system also accounts for about 40% of both total and freshwater US water withdrawals, i.e., water removed from its source regardless of fate. About 70% of withdrawals are associated with the once-through cooling systems of approximately 300 steam cycle power plants that produce about 25% of US electricity.

The United States has seven times as many intensive care unit (ICU) beds per capita as the United Kingdom; the effect on care of critically ill patients is unknown. To compare medical ICU admissions in the United States and United Kingdom. Retrospective (2002-2004) cohort study of 172,785 ICU admissions (137 United States ICUs, Project IMPACT database; 160 United Kingdom ICUs, Case Mix Program) with patients followed until initial hospital discharge. United Kingdom (vs. United States) admissions were less likely to be admitted directly from the emergency room (ER) (33.4% vs. 58%); had longer hospital stays before ICU admission (mean days 2.6 ± 8.2 vs. 1 ± 3.6); and fewer were greater than or equal to 85 years (3.2% vs. 7.8%). United Kingdom patients were more frequently mechanically ventilated within 24 hours after ICU admission (68% vs. 27.4%); were sicker (mean Acute Physiology Score 16.7 ± 7.6 vs. 10.6 ± 6.8); and had higher primary hospital mortality (38% vs. 15.9%; adjusted odds ratio, 1.73; 95% confidence interval, 1.50-1.99). There was no mortality difference for mechanically ventilated patients admitted from the ER (adjusted odds ratio, 1.09; 95% confidence interval, 0.89-1.33). Comparisons of hospital mortality were confounded by differences in case mix; hospital length of stay (United Kingdom median 10 d [interquartile range {IQR}, 3-24] vs. United States 6 d [IQR, 3-11]; and discharge practices (more United States patients were discharged to skilled care facilities [29% of survivors vs. 6% in the United Kingdom]). Lower United Kingdom ICU bed availability is associated with fewer direct admissions from the ER, longer hospital stays before ICU admission, and higher severity of illness. Interpretation of between-country hospital outcomes is confounded by differences in case mix, processes of care, and discharge practices.

Abstract. Human water withdrawal has increasingly altered the global water cycle in past decades, yet our understanding of its driving forces and patterns is limited. Reported historical estimates of sectoral water withdrawals are often sparse and incomplete, mainly restricted to water withdrawal estimates available at annual and country scales, due to a lack of observations at seasonal and local scales. In this study, through collecting and consolidating various sources of reported data and developing spatial and temporal statistical downscaling algorithms, we reconstruct a global monthly gridded (0.5∘) sectoral water withdrawal dataset for the period 1971–2010, which distinguishes six water use sectors, i.e., irrigation, domestic, electricity generation (cooling of thermal power plants), livestock, mining, and manufacturing. Based on the reconstructed dataset, the spatial and temporal patterns of historical water withdrawal are analyzed. Results show that total global water withdrawal has increased significantly during 1971–2010, mainly driven by the increase in irrigation water withdrawal. Regions with high water withdrawal are those densely populated or with large irrigated cropland production, e.g., the United States (US), eastern China, India, and Europe. Seasonally, irrigation water withdrawal in summer for the major crops contributes a large percentage of total annual irrigation water withdrawal in mid- and high-latitude regions, and the dominant season of irrigation water withdrawal is also different across regions. Domestic water withdrawal is mostly characterized by a summer peak, while water withdrawal for electricity generation has a winter peak in high-latitude regions and a summer peak in low-latitude regions. Despite the overall increasing trend, irrigation in the western US and domestic water withdrawal in western Europe exhibit a decreasing trend. Our results highlight the distinct spatial pattern of human water use by sectors at the seasonal and annual timescales. The reconstructed gridded water withdrawal dataset is open access, and can be used for examining issues related to water withdrawals at fine spatial, temporal, and sectoral scales.

Quantifying inorganic carbon fluxes to and from fresh waters is essential as part of understanding ecosystem functioning, potable water quality, and the amount of carbon exported to both the atmosphere and the oceans. Despite this, evidence of how anthropogenic withdrawals of fresh water perturb both land-fresh water-ocean and fresh water-atmosphere carbon fluxes is limited. Using the United States (US) as an exemplar, here we quantify for the first time the impact that both fresh surface water and fresh groundwater withdrawals by major water use sectors can have on land-fresh water-ocean and fresh water-atmosphere inorganic carbon fluxes. Fresh surface water withdrawals across the US during 2015 resulted in an estimated median gross dissolved inorganic carbon (DIC) retention flux of 8.5 (interquartile range: 6.5-11.3) Tg C yr-1, equivalent to 29% of the total export of DIC to the oceans from US rivers. The median gross retention flux due to fresh groundwater withdrawals was estimated to be 6.5 (interquartile range: 4.9-8.7) Tg C yr-1, over eight times the magnitude of the DIC flux to the oceans by subterranean groundwater discharging from the US. The median emission of CO2 from fresh waters to the atmosphere due to degassing of CO2 supersaturated groundwater following withdrawal was estimated to be 2.2 Tg CO2 yr-1 (interquartile range 1.2-4.3), 30% larger than previous estimates. Irrigation and public supply water use sectors contributed 70% and 19% of this total CO2 emission, respectively. County-level CO2 emissions from degassing groundwater following withdrawal exceeded the total county-level CO2 emissions from major emitting facilities across 1,391 counties, many of which were within Western and Midwestern states. This highlighted importance of freshwater withdrawals for DIC fluxes and CO2 emissions has implications for the accurate development of carbon budgets both across the United States, and for other regions around the world that are associated with significant freshwater withdrawals.

The United States Water Withdrawals Database (USWWD) provides a standardized compilation of user-level water withdrawal data across 42 US states. USWWD provides time series of water withdrawals at unprecedented spatial and temporal resolutions, encompassing 188,597 unique water users, 353,082 points of diversion and use, and 57,559,412 withdrawal volumes across various sectors. USWWD integrates diverse state-level data sources, standardizing information on water users, withdrawal locations, volumes, source types, and primary water use categories. The withdrawal data combines both direct measurements and various estimation techniques, reflecting the diverse methods utilized by different state agencies in reporting water usage. USWWD addresses significant gaps in national water use data, enabling researchers to conduct detailed analyses of water withdrawal patterns, trends, and drivers across space, time, and sectors. This granular dataset supports a wide range of applications, including water resource management, planning, and policy development. By providing the most detailed national water use data to date, USWWD facilitates new understanding of how society uses water.

After discharge from an acute care hospital, some children require ongoing care at a post-acute care hospital. Care transitions occur at both admission to the post-acute care hospital and again at discharge to the home/community. Our objective was to report the current practices used during the admission to and discharge from 7 pediatric post-acute care hospitals in the United States. Participants from 7 pediatric post-acute care hospitals completed a survey and rated the frequency of use of 20 practices to prepare and support children and their families during both admission to the hospital and at time of discharge to the home/community. For consistency with existing literature, practices were grouped into 4 previously reported categories: assessment, communication, education, and logistics. Descriptive statistics were used to report the frequency of use within practices and between hospitals. Only 2 of 10 admission practices and 3 of 10 discharge practices were reportedly "always" used by all hospitals. Assessment and communication practices were reported to be more frequently used (57%-100% of the time) than education and logistic procedures. Between hospitals, only the reported frequency of use of the discharge practices was statistically significantly different (P = .03). Variability exists in transition practices among 7 post-acute care pediatric hospitals. This report is the first known to detail the frequency of use of admission and discharge practices for pediatric post-acute care hospitals in the United States.

Introduction

Water requirements of selected industries

U.S. Energy Security and Water: The Challenges We Face

We provide a dataset of irrigation water withdrawals by crop, county, year, and water source within the United States. We employ a framework we previously developed to establish a companion dataset to our original estimates. The main difference is that we now use the U.S. Geological Survey (USGS) variable ‘irrigation — total’ to partition PCR-GLOBWB 2 hydrology model estimates, instead of ‘irrigation — crop’ as used in previous estimates. Our findings for Surface Water Withdrawals (SWW), total Groundwater Withdrawals (GWW), and nonrenewable Groundwater Depletion (GWD) are similar to those of prior estimates but now have better spatial coverage, since several states are missing from the USGS ‘irrigation — crop’ variable that was originally used. Irrigation water use increases in this study, since more states are included and ‘irrigation — total’ includes more categories of irrigation than ‘irrigation — crop’. Notably, irrigation in the Mississippi Embayment Aquifer is now captured for rice and soy. We provide nearly 2.5 million data points with this paper (3,142 counties; 13 years; 3 water sources; and 20 crops).

Future water security in the major basins of China under the 1.5 °C and 2.0 °C global warming scenarios

Irrigation has enhanced food security and biofuel production throughout the world. However, the sustainability of irrigation faces challenges from climate variability and extremes, increasing consumption from irrigated cropland expansion, and competing demands from other water use sectors. In this study, we investigated the agricultural water withdrawal landscape of the contiguous United States (CONUS) over 1981–2015, assessed its spatial and temporal changes, and analyzed the factors driving the changes. We introduced the concept of ‘center of mass’ to calculate the spatiotemporal trajectory of water withdrawal, along with climatic and agricultural factors at state, regional and CONUS scales. At the CONUS level, the total agricultural water withdrawal has decreased during 1981–2015, and the centroid of water withdrawal consistently moved toward the east, caused by reduced water withdrawal in the western states and increased withdrawal in the eastern states. While the CONUS irrigation trajectory is not mainly affected by climatologic trends, extreme drought conditions (e.g. the mega droughts in western states since 2000) may interrupt the trend. In the Western US, irrigation withdrawal reduction was mainly achieved by adoption of high-efficiency irrigation technology, while the irrigated acreage remains relatively stable. Under drought conditions, irrigation withdrawal often switched from surface water to groundwater sources, posing challenges on groundwater sustainability under prolonged drought conditions. The Eastern US has experienced accelerating agricultural withdrawal from both surface water and groundwater sources. This was mainly driven by expansion in irrigated acreage in the Midwest and lower Mississippi River, with irrigated croplands supplied by mixed flood irrigation and high-efficiency irrigation methods. At the state level, some states exhibited discrepancy in agricultural withdrawal centroids from surface water and groundwater sources, as results of climate heterogeneity, water availability and infrastructure development. This study provides understanding of the driving forces in the spatiotemporal trends of CONUS agricultural water withdrawal in different regions and implications for predicting future agricultural withdrawal under changing climatic and socioeconomic uncertainties.

Comparisons of Hospital Bed Utilization in Australia and the United States Using DRGs

The artificial sweetener sucralose has recently been shown to be a widespread of contaminant of wastewater, surface water, and groundwater. In order to understand its occurrence in drinking water systems, water samples from 19 United States (U.S.) drinking water treatment plants (DWTPs) serving more than 28 million people were analyzed for sucralose using liquid chromatography tandem mass spectrometry (LC-MS/MS). Sucralose was found to be present in source water of 15 out of 19 DWTPs (47-2900 ng/L), finished water of 13 out of 17 DWTPs (49-2400 ng/L) and distribution system water of 8 out of the 12 DWTPs (48-2400 ng/L) tested. Sucralose was only found to be present in source waters with known wastewater influence and/or recreational usage, and displayed low removal (12% average) in the DWTPs where finished water was sampled. Further, in the subset of DWTPs with distribution system water sampled, the compound was found to persist regardless of the presence of residual chlorine or chloramines. In order to understand intra-DWTP consistency, sucralose was monitored at one drinking water treatment plant over an 11 month period from March 2010 through January 2011, and averaged 440 ng/L in the source water and 350 ng/L in the finished water. The results of this study confirm that sucralose will function well as an indicator compound for anthropogenic influence on source, finished drinking and distribution system (i.e., tap) water, as well as an indicator compound for the presence of other recalcitrant compounds in finished drinking water in the U.S.