Though surface water quality has been monitored in southern Peru over the past and current century, it has been implemented by multiple organizations. The data lacks a centralized repository and access requires logistical and temporal hurdles associated with official requests. A substantial portion of the data has not been quality assured and is in difficult-to-access formats such as scanned PDF documents. These obstacles collectively make it challenging to maximize the impact of these monitoring efforts such as efficiently evaluating long-term water quality trends. To address this opportunity, we gathered available surface water quality information from five watersheds in the Arequipa Region of southern Peru: Camaná, Chili, Ocoña, Tambo, and Yauca. The effort required entry of more than 130,000 records of water quality properties across 274 monitoring stations with data including the concentration of select nutrients, metals, organic compounds, and biological taxa. The water quality records in the Chili watershed go back as far as 1905, while data for the other watersheds was largely confined to the years 2012-2021. This document describes how the surface water quality information was assimilated with quality control and provides a centralized Excel database so that the data can be efficiently used for research and decision making purposes.

Climate change and increases in human activities are threatening water availability in the Arequipa Region (southern Peru). However, to date, there has not been a comprehensive inventory of surface water data or an investigation of current surface water conditions or forecasted future conditions resulting from increased anthropic demand or stresses from climate change. This study evaluates surface water resources management including storage, diversions, and conveyance in the Arequipa Region, while creating a tool for the evaluation of future scenarios in the five main watersheds of this arid region of southern Peru. State-of-the art, open-source modeling software was used. Water uses for each watershed were evaluated against predicted reservoir inflows and streamflows for different periods. In addition to the above, 12 climate change models and different shared socioeconomic pathways (SSP) were ensembled for the five watersheds. A semi-distributed approach and an innovative simulation splitting approach was used for each watershed, which allowed for different starting dates for the simulations using all available data obtained from different sources (government and private). Results indicate that the region is expected to have increased flows during the wet season and no significant changes during the dry season. Reservoir inflows are expected to increase up to 42 and 216% for the lowest and highest SSP evaluated, respectively. Similarly, the model projected streamflow increases up to 295 and 704%, respectively. Regarding yearly water availability and considering current and future demands for the watersheds under study, water deficits are not expected in the future if current reservoir storage can be maintained, though it is expected that reservoirs won’t be able to store predicted higher flows, so important volumes of water could be lost during the wet season to the ocean by natural drainage. Given the uncertainty of climate change projections, if future water sustainability is desired, storage and irrigation efficiencies should be improved and reservoir sedimentation should be evaluated.

ABSTRACT In the period between 1961 and 2008, Oklahoma, USA, averaged about two M ≥3.0 earthquakes per year, with no damage to any built infrastructure. A substantial increase in seismic activity was first observed in 2009, when there were 20 M ≥3.0 earthquakes, and activity peaked in 2015, when over 900 M ≥3.0 earthquakes occurred. Because of the unprecedented increase in seismic activity, the governor’s office of Oklahoma formed a Coordinating Council of researchers, regulators, industry, and other stakeholders in 2015. The Coordinating Council was led by the Secretary of Energy and Environment and charged with understanding and attempting to mitigate (that is, reduce, if not eliminate) induced seismicity and potential impacts. Major outcomes of the coordinated efforts included delineation of an area of interest (AOI) for seismicity in Oklahoma, modifications to underground injection control (UIC) well completion depths and injection rates into UIC wells in the AOI, development of the Oklahoma Well and Seismic Monitoring (OWSM) application used for regulatory oversight and action, modified well completion protocols, a more robust seismic network, and numerous scientific investigations and publications. Because of concerted efforts between regulators and industry, disposal into the Arbuckle Group, the primary zone for wastewater disposal, in the AOI was reduced by more than 50% though oil production continued to increase. Seismic activity decreased over a 6 yr period with 619, 302, 195, 65, 39, and 29 M ≥3.0 earthquakes occurring in 2016, 2017, 2018, 2019, 2020, and 2021, respectively. At the time of latest updates to this chapter (16 October 2022), there have been 12 M ≥3.0 earthquakes and one M ≥4.0 earthquake, so the projected total of M ≥3.0 earthquakes in 2022 is 17. Using these metrics, the coordinated efforts of Oklahoma stakeholders appear to have successfully reduced seismicity with respect to frequency and number in the range of minor but often felt (M 3.0–3.9), light (M 4.0–4.9), and moderate (M 5.0–5.9) earthquakes. So, the Oklahoma case provides examples of how stakeholder action diminished seismic hazards and how similar actions could be used to reduce induced seismicity in other areas where injections occur.

With the U.S. unconventional oil revolution, adverse impacts from subsurface disposal of coproduced water, such as induced seismicity, have markedly increased, particularly in Oklahoma. Here, we adopt a new, more holistic analysis by linking produced water (PW) volumes, disposal, and seismicity in all major U.S. unconventional oil plays (Bakken, Eagle Ford, and Permian plays, and Oklahoma) and provide guidance for long-term management. Results show that monthly PW injection volumes doubled across the plays since 2009. We show that the shift in PW disposal to nonproducing geologic zones related to low-permeability unconventional reservoirs is a fundamental driver of induced seismicity. We statistically associate seismicity in Oklahoma to (1) PW injection rates, (2) cumulative PW volumes, and (3) proximity to basement with updated data through 2017. The major difference between intensive seismicity in Oklahoma versus low seismicity levels in the Bakken, Eagle Ford, and Permian Basin plays is attributed to proximity to basement with deep injection near basement in Oklahoma relative to shallower injection distant from basement in other plays. Directives to mitigate Oklahoma seismicity are consistent with our findings: reducing (1) PW injection rates and (2) regional injection volumes by 40% relative to the 2014 total in wells near the basement, which resulted in a 70% reduction in the number of M >= 3.0 earthquakes in 2017 relative to the 2015 peak seismicity. Understanding linkages between PW management and seismicity allows us to develop a portfolio of strategies to reduce future adverse impacts of PW management, including reuse of PW for hydraulic fracturing in the oil and gas sector. Electronic Supplement: Additional information on methods; a more detailed bubble plot containing water and energy information; maps of oil- and gas-producing wells and saltwater disposal and enhanced oil-recovery wells; a geologic cross section of the Permian Basin; boxplots showing the statistical data evaluating relationships between produced water management and seismicity; tables listing the number of earthquakes in each of the plays, oil, gas, produced-water volumes, and management of produced water using saltwater disposal and enhanced oil recovery.

Many previous studies have suggested that wastewater disposal is the most probable factor affecting increased seismicity in Oklahoma since 2009. While this relationship is clear at the state scale, a systematic quantitative analysis of the spatiotemporal relationships between injection and seismicity is needed. We first apply multiscale analyses to assess the temporal correlation between injection rate and seismicity rate at a range of different grid sizes, which demonstrate clear temporal correlations within the two main seismic regions at variable time delays. The time delay variability decreases with larger grid sizes, whereby the average time delay ranges from 150 to 220 days. The average time delay at large scales is consistent with inferred large‐scale diffusive migration away from areas of high injection rates with diffusivities of 0.5 to 2.0 m2/s. The inferred large‐scale diffusivities are consistent with an expected range of diffusivity within the Arbuckle Group where wastewater disposals are occurring. However, individual earthquake clusters have diffusivities that are about one to two orders lower than the large‐scale models. We interpret this as a manifestation of a two‐layered diffusion model with high diffusivity within the injection layer above basement, which facilitates stress transfer at a larger spatial footprint, triggering seismic slip at multiple seismogenic faults within the crystalline basement with low diffusivity, similar to fluid‐driven clusters in other tectonic regions.

The Arbuckle Group (Arbuckle) is a basal sedimentary unit that is the primary target for saltwater disposal in Oklahoma. Thus, the reservoir characteristics of the Arbuckle, including how the poroelastic properties change laterally and over time are of significant interest. We report observations of fluid level changes in two monitoring wells in response to the 3 September 2016 Mw 5.8 Pawnee and the 7 November 2016 Mw 5.0 Cushing earthquakes. We investigate the relationship between static strain resulting from these events and the fluid level changes observed in the wells. We model the fluid level response by estimating static strains from a set of earthquake source parameters and spatiotemporal poroelastic properties of the Arbuckle in the neighborhood of the monitoring wells. Results suggest that both the direction of the observed fluid level step and the amplitude can be predicted from the computed volumetric strain change and a reasonable set of poroelastic parameters. Modeling results indicate that poroelastic parameters differ at the time of the Pawnee and Cushing earthquakes, with a moderately higher Skempton’s coefficient required to fit the response to the Cushing earthquake. This may indicate that dynamic shaking resulted in physical alteration of the Arbuckle at distances up to ∼50 km from the Pawnee earthquake. Electronic Supplement: Overview map of the region of interest in Oklahoma along with seismicity, well completion diagrams, sensitivity of the root mean square (rms) error to the input parameters, and tables showing the best-fitting source and poroelastic parameters.

The Arbuckle Group (Arbuckle) is a basal sedimentary unit that is the primary target for saltwater disposal in Oklahoma. Thus, the reservoir characteristics of the Arbuckle, including how the poroelastic properties change laterally and over time are of significant interest. We report observations of fluid level changes in two monitoring wells in response to the 3 September 2016 M-w 5.8 Pawnee and the 7 November 2016 M-w 5.0 Cushing earthquakes. We investigate the relationship between static strain resulting from these events and the fluid level changes observed in the wells. We model the fluid level response by estimating static strains from a set of earthquake source parameters and spatiotemporal poroelastic properties of the Arbuckle in the neighborhood of the monitoring wells. Results suggest that both the direction of the observed fluid level step and the amplitude can be predicted from the computed volumetric strain change and a reasonable set of poroelastic parameters. Modeling results indicate that poroelastic parameters differ at the time of the Pawnee and Cushing earthquakes, with a moderately higher Skempton's coefficient required to fit the response to the Cushing earthquake. This may indicate that dynamic shaking resulted in physical alteration of the Arbuckle at distances up to similar to 50 km from the Pawnee earthquake.

The state of Oklahoma has experienced an unprecedented increase in earthquake activity since 2009, likely driven by large-scale wastewater injection operations. Statewide injection rates peaked in early 2015 and steadily decreased thereafter, approximately coinciding with collapsing oil prices and regulatory action. If seismic activity is primarily driven by fluid injection, a noticeable seismogenic response to the decrease in injection rates is expected. Langenbruch and Zoback suggest that “the probability of potentially damaging larger events, should significantly decrease by the end of 2016 and approach historic levels within a few years.” We agree that the rate of small earthquakes has decreased toward the second half of 2016. However, their specific predictions about seismic hazard require reexamination. We test the influence of the model parameters of Langenbruch and Zoback based on fits to observed seismicity distributions. The results suggest that a range of realistic aftershock decay rates and b values can lead to an increase in moderate earthquake probabilities from 37 to 80% in 2017 without any further alteration to the model. In addition, the observation that all four M ≥ 5 earthquakes to date occurred when injection rates were below the triggering threshold of Langenbruch and Zoback challenges the applicability of the model for the most societally significant events.

This study systematically reviewed the methodology and findings of 24 peer-reviewed studies on psychosocial risk factors associated with the mental health of undocumented immigrants (UIs) in the United States. Of these studies, 14 included quantitative data and 13 were qualitative. The most common recruitment methods were snowball techniques, and most studies used convenience samples of recent UI Latinos. The method of assessing legal status varied, including current versus retrospective undocumented status. Psychological distress, depression, anxiety, and substance use/abuse were identified as prevalent themes. Studies with enhanced methodological rigor are needed.

Microorganisms are ubiquitous in natural environments and in water supply infrastructure including groundwater wells. Sessile-state microorganisms may build up on well surfaces as biofilms and, if excessive, cause biofouling that reduces well productivity and water quality. Conditions can be improved using biocides and other traditional well rehabilitation measures; however, biofilm regrowth is inevitable given the continuous introduction of microorganisms from the surrounding environment. Alternative and less invasive well maintenance approaches are desirable for reducing biofilm densities while also minimizing harmful disinfection-by-products. The primary objective of this research was to evaluate effectiveness of alternative treatments for inactivating microorganisms comprising biofilms. A novel approach was designed for in situ growth of biofilms on steel coupons suspended from ‘chandeliers’. After more than 100 days of in situ growth, biofilms were harvested, sampled, and baseline biofilm densities quantified through cultivation. Ultraviolet-C (UV-C) and oxidative treatments including hydrogen peroxide (H2O2), ozone (O3) and mixed oxidants were then applied to the biofilms in laboratory-scale treatments. Microbial inactivation was assessed by comparing treated versus baseline biofilm densities. H2O2 was the most effective treatment, and decreased density below baseline by as much as 3.1 orders of magnitude. Mixed oxidants were effective for the well having a lower density biofilm, decreasing density below baseline by as much as 1.4 orders of magnitude. Disparity in the response to treatment was apparent in the wells despite their spatial proximity and common aquifer source, which suggests that microbiological communities are more heterogeneous than the natural media from which they originate.

Oil shale deposits of the Green River Formation (GRF) in Northwestern Colorado, Southwestern Wyoming, and Northeastern Utah may become one of the first oil shale deposits to be developed in the U.S. because of their richness, accessibility, and extensive prior characterization. Oil shale is an organic-rich fine-grained sedimentary rock that contains significant amounts of kerogen from which liquid hydrocarbons can be produced. Water is needed to retort or extract oil shale at an approximate rate of three volumes of water for every volume of oil produced. Concerns have been raised over the demand and availability of water to produce oil shale, particularly in semiarid regions where water consumption must be limited and optimized to meet demands from other sectors. The economic benefit of oil shale development in this region may have tradeoffs within the local and regional environment. Due to these potential environmental impacts of oil shale development, water usage issues need to be further studied. A basin-wide baseline for oil shale and water resource data is the foundation of the study. This paper focuses on the design and construction of a centralized geospatial infrastructure for managing a large amount of oil shale and water resource related baseline data, and for setting up the frameworks for analytical and numerical models including but not limited to three-dimensional (3D) geologic, energy resource development systems, and surface water models. Such a centralized geospatial infrastructure made it possible to directly generate model inputs from the same database and to indirectly couple the different models through inputs/outputs. Thus ensures consistency of analyses conducted by researchers from different institutions, and help decision makers to balance water budget based on the spatial distribution of the oil shale and water resources, and the spatial variations of geologic, topographic, and hydrogeological characterization of the basin. This endeavor encountered many technical challenging and has not been done in the past for any oil shale basin. The database built during this study remains valuable for any other future studies involving oil shale and water resource management in the Piceance Basin. The methodology applied in the development of the GIS based geospatial infrastructure can be readily adapted for other professionals to develop database structure for other similar basins.