CV-SALTS Central Valley Region Salt & Nitrate Control Program Surveillance and Monitoring Program

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | February 3rd, 2023

The prioritized Nitrate Control Program and phased Salt Control Program are designed to address both legacy and ongoing salt and nitrate accumulation issues in groundwate

The prioritized Nitrate Control Program and phased Salt Control Program are designed to address both legacy and ongoing salt and nitrate accumulation issues in groundwater and salinity concerns in surface waters. However, the primary focus of early actions being implemented under the Nitrate Control Program (i.e., the first ten years) is on groundwater quality and in particular nitrate impacts to drinking water supplies. The overarching management goals and priorities of the SNCP are to: Ensure safe drinking water supply; Reduce salt and nitrate loading so that ongoing discharges neither threaten to degrade high quality waters absent appropriate findings by the Central Valley Board, nor cause or contribute to exceedances of water quality objectives; and Implement long-term, managed restoration of impaired waterbodies.

CV-SALTS Groundwater Sustainability Plan Data Collection - Pilot Study Results

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | February 1st, 2024

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize relevan

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize relevant GSP data and information that can be used to (1) validate or refine information contained in the P&O Study’s CV-SWAT watershed model (developed to support ongoing baseline characterization work); (2) support the eventual development of salinity management alternatives within specified planning areas; and (3) help ensure that long-term Central Valley salt planning considers ongoing Groundwater Sustainability Agency (GSA) planning efforts, which is of particular interest to the State Water Resources Control Board.

CV-SALTS Groundwater Sustainability Plan Data Integration Report Integrated Scope of Work - Task 5.3 (Draft)

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | June 20th, 2024

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize

The purpose of Prioritization & Optimization (P&O) Study Task 5.3 (Information Extraction from Groundwater Sustainability Plans [GSP]) is to extract and organize relevant GSP data and information that can be used to: Validate or refine information contained in the P&O Study’s Central Valley Soil and Water Assessment Tool (CV-SWAT) watershed model and other models (developed to support ongoing baseline characterization work and future salinity-related analyses); Support the eventual development of salinity management alternatives within specified Central Valley planning areas; and Help ensure that long-term Central Valley salt planning understands and considers ongoing Groundwater Sustainability Agency (GSA) planning efforts, efforts and potential future conditions of the water in the Central Valley region and benefits from the local investment in these plans. It is also expected that this report will be a foundation for enhanced coordination with GSAs as planning occurs in their regions. Click below for document appendices.  Appendix A: Selected GSP Information Summaries by Hydrologic Region Appendix B: Appendix B 1 - Sac Valley Hydrologic Region - GSP Hydrogeologic Conceptual Model Excerpts and Near AEM Profiles Appendix B 2 - San Joaquin Valley Hydrologic Region - GSP Hydrologic Conceptual Model Excerpts and Near AEM Profiles Appendix B 3 - Tulare Lake Hydrologic Region - GSP Hydrogeologic Conceptual Model Excerpts and Near AEM Profiles

CV-SALTS Prioritization & Optimization Study: Final Baseline Characterization Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 9th, 2024

The Central Valley Regional Water Quality Control Board (Central Valley Water Board) first adopted a three-phased Salt Control Program into the water quality regulations

The Central Valley Regional Water Quality Control Board (Central Valley Water Board) first adopted a three-phased Salt Control Program into the water quality regulations applicable to the Central Valley Region of California in 2018; these regulations were subsequently amended in 2020. Phase I of the Salt Control Program requires implementation of the Prioritization and Optimization (P&O) Study. The primary purposes of this Study are to characterize existing salinity conditions in surface water and groundwater in the Central Valley Region, establish appropriate salinity targets for the protection of beneficial uses, and facilitate the development of long-term salt management alternatives for implementation in Phases II and III of the Salt Control Program.

Data from a Thick Unsaturated Zone Underlying Oro Grande and Sheep Creek Washes in the Western Part of the Mojave Desert, near Victorville, San Bernardino County, California

U.S. Geological Survey (USGS) | January 1st, 2000

This report presents data collected as part of a cooperative study of infiltration and groundwater recharge to the regional aquifer near Victorville, California.

This report presents data collected as part of a cooperative study of infiltration and groundwater recharge to the regional aquifer near Victorville, California. The study was funded by the U.S. Geological Survey (USGS) and the Mojave Water Agency. This report contains data on drilling, instrument installation, the physical properties of unsaturated earth materials, and the chemical and isotopic composition of leachate from cores and cuttings, soil water, and soil gas collected at sites underlying Oro Grande and Sheep Creek Washes in the Mojave Desert. The report also presents similar data collected at sites on the alluvial fan near these washes and at a site near Cajon Pass. The sites on the alluvial fan and near Cajon Pass served as controls for the study and allow for comparison with data from previous studies. In addition, the report presents data on the chemical and isotopic composition of bulk precipitation, and on groundwater levels and quality. Interpretation of these data is beyond the scope of this report.

Data from Exploratory Sampling of Groundwater in Selected Oil and Gas Areas of Coastal Los Angeles County and Kern and Kings Counties in Southern San Joaquin Valley, 2014–15

U.S. Geological Survey (USGS) | December 9th, 2016

Exploratory sampling of groundwater in coastal Los Angeles County and Kern and Kings Counties of the southern San Joaquin Valley was done by the U.S. Geological Survey fr

Exploratory sampling of groundwater in coastal Los Angeles County and Kern and Kings Counties of the southern San Joaquin Valley was done by the U.S. Geological Survey from September 2014 through January 2015 as part of the California State Water Resources Control Board’s Water Quality in Areas of Oil and Gas Production Regional Groundwater Monitoring Program. The Regional Groundwater Monitoring Program was established in response to the California Senate Bill 4 of 2013 mandating that the California State Water Resources Control Board design and implement a groundwater-monitoring program to assess potential effects of well-stimulation treatments on groundwater resources in California. The U.S. Geological Survey is in cooperation with the California State Water Resources Control Board to collaboratively implement the Regional Groundwater Monitoring Program through the California Oil, Gas, and Groundwater Project. Many researchers have documented the utility of different suites of chemical tracers for evaluating the effects of oil and gas development on groundwater quality. The purpose of this exploratory sampling effort was to determine whether tracers reported in the literature could be used effectively in California. This reconnaissance effort was not designed to assess the effects of oil and gas on groundwater quality in the sampled areas. A suite of water-quality indicators and geochemical tracers were sampled at groundwater sites in selected areas that have extensive oil and gas development. Groundwater samples were collected from a total of 51 wells, including 37 monitoring wells at 17 multiple-well monitoring sites in coastal Los Angeles County and 5 monitoring wells and 9 water-production wells in southern San Joaquin Valley, primarily in Kern and Kings Counties. Groundwater samples were analyzed for field water-quality indicators; organic constituents, including volatile and semi-volatile organic compounds and dissolved organic carbon indicators; naturally present inorganic constituents, including trace elements, nutrients, major and minor ions, and iron species; naturally present stable and radioactive isotopes; dissolved noble gases; dissolved standard and hydrocarbon gases, ?13C of methane, ethane, and ?2H of methane. In total, 249 constituents and water-quality indicators were measured. Four types of quality-control samples (blanks, replicates, matrix spikes, and surrogates spiked in environmental and blank samples) were collected at approximately 10 percent of the wells. The quality-control data were used to determine whether the groundwater-sample data were of sufficient quality for the measured analytes to be used as potential indicators of oil and gas effects. The data from the 51 groundwater samples and from the quality-control samples are presented in this report.

Data Measured on Water Collected from Eastern Mojave Desert, California

U.S. Department of Energy (DOE) | August 18th, 2017

In March of 2000 field collection of water from the Eastern Mojave Desert resulted in the measurement of stable isotope, radiocarbon, tritium, and limited dissolved nobl

In March of 2000 field collection of water from the Eastern Mojave Desert resulted in the measurement of stable isotope, radiocarbon, tritium, and limited dissolved noble gases. This work was follow-on to previous studies on similar systems in southern Nevada associated with the Nevada Test Site (Davisson et al., 1999; Rose and Davisson, 2003). The data for groundwater from wells and springs was never formally published and is therefore tabulated in Table 1 in order to be recorded in public record. In addition 4 years of remote precipitation data was collected for stable isotopes and is included in Table 2. These studies, along with many parallel and subsequent ones using isotopes and elemental concentrations, are all related to the general research area of tracing sources and quantifying transport times of natural and man-made materials in the environment. This type of research has direct relevance in characterizing environmental contamination, understanding resource development and protection, designing early detection in WMD related terrorism, and application in forensics analysis.

Death Valley lower carbonate aquifer monitoring program—Wells down gradient of the proposed Yucca Mountain nuclear waste repository: U.S. Department of Energy Cooperative Agreement DE-FCO8-02RW12162 Final Project Report

Inyo County | July 1st, 2005

Death Valley regional ground-water flow system, Nevada and California—Hydrogeologic framework and transient ground-water flow model

U.S. Geological Survey (USGS) | July 1st, 2010

A numerical three-dimensional (3D) transient groundwater flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Ener

A numerical three-dimensional (3D) transient groundwater flow model of the Death Valley region was developed by the U.S. Geological Survey for the U.S. Department of Energy programs at the Nevada Test Site and at Yucca Mountain, Nevada. Decades of study of aspects of the groundwater flow system and previous less extensive groundwater flow models were incorporated and reevaluated together with new data to provide greater detail for the complex, digital model. A 3D digital hydrogeologic framework model (HFM) was developed from digital elevation models, geologic maps, borehole information, geologic and hydrogeologic cross sections, and other 3D models to represent the geometry of the hydrogeologic units (HGUs). Structural features, such as faults and fractures, that affect groundwater flow also were added. The HFM represents Precambrian and Paleozoic crystalline and sedimentary rocks, Mesozoic sedimentary rocks, Mesozoic to Cenozoic intrusive rocks, Cenozoic volcanic tuffs and lavas, and late Cenozoic sedimentary deposits of the Death Valley regional groundwater flow system (DVRFS) region in 27 HGUs. Information from a series of investigations was compiled to conceptualize and quantify hydrologic components of the groundwater flow system within the DVRFS model domain and to provide hydraulic-property and head-observation data used in the calibration of the transient-flow model. These studies reevaluated natural groundwater discharge occurring through evapotranspiration (ET) and spring flow; the history of groundwater pumping from 1913 through 1998; groundwater recharge simulated as net infiltration; model boundary inflows and outflows based on regional hydraulic gradients and water budgets of surrounding areas; hydraulic conductivity and its relation to depth; and water levels appropriate for regional simulation of prepumped and pumped conditions within the DVRFS model domain. Simulation results appropriate for the regional extent and scale of the model were provided by acquiring additional data, by reevaluating existing data using current technology and concepts, and by refining earlier interpretations to reflect the current understanding of the regional groundwater flow system. Groundwater flow in the Death Valley region is composed of several interconnected, complex groundwater flow systems. Groundwater flow occurs in three subregions in relatively shallow and localized flow paths that are superimposed on deeper, regional flow paths. Regional groundwater flow is predominantly through a thick Paleozoic carbonate rock sequence affected by complex geologic structures from regional faulting and fracturing that can enhance or impede flow. Spring flow and ET are the dominant natural groundwater discharge processes. Groundwater also is withdrawn for agricultural, commercial, and domestic uses. Groundwater flow in the DVRFS was simulated using MODFLOW-2000, the U.S. Geological Survey 3D finitedifference modular groundwater flow modeling code that incorporates a nonlinear least-squares regression technique to estimate aquifer parameters. The DVRFS model has 16 layers of defined thickness, a finite-difference grid consisting of 194 rows and 160 columns, and uniform cells 1,500 meters (m) on each side. Prepumping conditions (before 1913) were used as the initial conditions for the transient-state calibration. The model uses annual stress periods with discrete recharge and discharge components. Recharge occurs mostly from infiltration of precipitation and runoff on high mountain ranges and from a small amount of underflow from adjacent basins. Discharge occurs primarily through ET and spring discharge (both simulated as drains) and water withdrawal by pumping and, to a lesser amount, by underflow to adjacent basins simulated by constant-head boundaries. All parameter values estimated by the regression are reasonable and within the range of expected values. The simulated hydraulic heads of the final calibrated transient model generally fit observed heads reasonably well (residuals with absolute values less than 10 meters) with two exceptions: in most areas of nearly flat hydraulic gradient the fit is considered moderate (residuals with absolute values of 10 to 20 meters), and in areas of steep hydraulic gradient along the Eleana Range and western part of Yucca Flat, southern part of the Owlshead Mountains, southern part of the Bullfrog Hills, and the north-northwestern part of the model domain (residuals with absolute values greater than 20 meters). Groundwater discharge residuals are fairly random, with as many areas where simulated flows are less than observed flows as areas where simulated flows are greater. The highest unweighted groundwater discharge residuals occur at Death Valley, Sarcobatus Flat (northeastern area), Tecopa, and early observations at Manse Spring in Pahrump Valley. High weighted-discharge residuals were computed in Indian Springs Valley and parts of Death Valley. Most of these inaccuracies in head and discharge can be attributed to insufficient representation of the hydrogeology in the HFM and(or) discharge estimates, misrepresentation of water levels, and(or) model error associated with grid-cell size. The model represents the large and complex groundwater flow system of the Death Valley region at a greater degree of refinement and accuracy than has been possible previously. The representation of detail provided by the 3D digital hydrogeologic framework model and the numerical groundwater flow model enabled greater spatial accuracy in every model parameter. The lithostratigraphy and structural effects of the hydrogeologic framework; recharge estimates from simulated net infiltration; discharge estimates from ET, spring flow, and pumping; and boundary inflow and outflow estimates all were reevaluated, some additional data were collected, and accuracy was improved. Uncertainty in the results of the flow model simulations can be reduced by improving on the quality, interpretation, and representation of the water-level and discharge observations used to calibrate the model and improving on the representation of the HGU geometries, the spatial variability of HGU material properties, the flow model physical framework, and the hydrologic conditions.

Death Valley regional groundwater flow system, Nevada and California—Hydrogeologic framework and transient ground-water flow model

U.S. Geological Survey (USGS) | August 23rd, 2010