This data release contains data used to develop models and maps that estimate the occurrence of lithium in groundwater used as drinking water throughout the conterminous United States. An extreme gradient boosting model was developed to estimate the most probable lithium concentration category (≤4, >4 to ≤10, >10 to ≤30 or >30 µg/L). The model uses lithium concentration data from wells located throughout the conterminous United States and predictor variables that are available as geospatial data. The model is included in this data release in the zipped folder named Model_Archive and was used to produce maps that are also included in this data release. The model input data (predictor variables) that were used to make the maps are within a zipped folder (Map_Input_Data.zip) that contains 20 tif-raster files, one for each model predictor variable. The map probability estimates that are outputs from the model are in a zipped folder (Map_Output_Data.zip) that contains 10 tif-raster files, two model estimate maps for each of the lithium concentration categories and the category with the highest probability for public supply well depths and domestic supply well depths.

This web map was created for use in its respective dashboard, in support of California's Groundwater Live.The web map includes data for current groundwater levels statewide.For inquiries, please email calgw@water.ca.gov.

This map layer contains the shallowest principal aquifers of the conterminous United States, Hawaii, Puerto Rico, and the U.S. Virgin Islands, portrayed as polygons. The map layer was developed as part of the effort to produce the maps published at 1:2,500,000 in the printed series "Ground Water Atlas of the United States". The published maps contain base and cultural features not included in these data. This is a replacement for the July 1998 map layer called Principal Aquifers of the 48 Conterminous United States.

Groundwater Elevation Change Maps summarize the change in groundwater level measurements over time, collected from wells in the northern Sacramento Valley by the Department of Water Resources (DWR) Northern Region Office (NRO) and monitoring cooperators. Northern Sacramento Valley groundwater levels are measured seasonally, during the annual water year, as part of our ongoing data collection program. Many of the wells have over 30 years of monitoring history, with the longest active monitoring well dating back to 1921. Groundwater level data provides valuable information regarding seasonal fluctuations and long-term changes in groundwater level trends over time. The groundwater level data presented in these figures includes the Sacramento Valley and Redding groundwater basin portions of Shasta, Tehama, Butte, Colusa, Glenn, and Sutter counties and are organized by year, season, well depth, and period of change.

A comprehensive picture, at European Union scale, of the aquifers and their characteristics is available in digital form. In 1982, a study by the European Commission provided a complete catalogue of national water resources for several Member States of the European Union (Belgium, Federal Republic of Germany, Denmark, France, Ireland, Italy, Luxembourg, Netherlands and United Kingdom).

This catalogue comprised a series of groundwater resources maps of Europe, at scale 1:500,000 ; there were 38 map sheets covering four themes:

-Inventory of aquifers; -Hydrogeology of aquifers; -Groundwater abstraction; -Potential additional groundwater resources.

[Summary provided by the European Union Joint Research Center.]

Groundwater in the arid Mountain Home area is vital to agricultural, municipal, industrial and other water users who are concerned about declining groundwater levels. The U.S. Geological Survey, in cooperation with the Idaho Department of Water Resources (IDWR), developed a hydrogeologic framework to provide a conceptual understanding of groundwater resources in the Mountain Home area. As part of the hydrogeologic framework, water-table contour and groundwater-level change maps were produced to describe the occurrence, movement, and change in groundwater. Water-table contours for spring 2023 (March 20 to 24, 2023) and autumn 2023 (November 1 to 7, 2023) were created for the regional aquifer and perched groundwater zone in the Mountain Home area. The well numbers and station names for sites used to create the water-table contours and groundwater-level change and groundwater storage change rasters are provided in this data release. The _location, depth to water, and groundwater altitude for these wells can be accessed on USGS National Water Information System (NWIS), IDWR groundwater portal, or an annual water level monitoring report for IDWR permit 61-12090 (HDR, 2024). The interpreted 50-foot contours of the water table are also provided in this data release. The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The water-table contours are divided into two water-bearing units - regional and perched groundwater zone - based on well depth and groundwater altitude. The water-table contours ranged from 2,350 to 3,650 feet above NAVD 88. The groundwater-level change at well sites from spring to autumn 2023 were interpolated over the study area and are provided in a raster. Groundwater-level change ranged from 22.01 ft decline to 15.44 ft rise. Groundwater-level change was multiplied by hydrogeologic unit storativity to estimate groundwater storage change from spring to autumn 2023. More information on the generation of the water-table contours, groundwater change maps, and perched groundwater delineation and limitations can be found in the companion report, SIR 2024-5124 (Hydrogeologic framework of the Mountain Home area, southern Idaho by L.M. Zinsser and S.D. Ducar).

Union County, the northeasternmost county in New Mexico, is rural with an economy based on ranching and agriculture. Surface water resources are limited, thus development of groundwater for stock watering and irrigation is important and extensive. Groundwater studies by the New Mexico Bureau of Geology and Mineral Resources (NMBGMR) in Union County have been conducted in concert with the Northeast Soil and Water Conservation District (NESWCD) and were driven by concerns over recent large groundwater appropriations, the reliability of the groundwater supply for the town of Clayton, and declining water levels that have been observed in many wells over the past few years.

The New Mexico Office of the State Engineer (NMOSE) declared the Clayton Underground Water Basin in 2005, ending unrestricted appropriation and development of groundwater in northeast New Mexico. Recently, the NMOSE has started development of a groundwater flow model of the Clayton Basin for administration of water rights. Important input data for a groundwater flow model include accurate delineation of the groundwater surface and an understanding of water level changes over time.

This dataset is available for use for non-commercial purposes only on request as AfA248 dataset Groundwater Vulnerability Maps (2017). For commercial use please contact the British Geological Survey.

The Groundwater Vulnerability Maps show the vulnerability of groundwater to a pollutant discharged at ground level based on the hydrological, geological, hydrogeological and soil properties within a single square kilometre. The 2017 publication has updated the groundwater vulnerability maps to reflect improvements in data mapping, modelling capability and understanding of the factors affecting vulnerability Two map products are available: • The combined groundwater vulnerability map. This product is designed for technical specialists due to the complex nature of the legend which displays groundwater vulnerability (High, Medium, Low), the type of aquifer (bedrock and/or superficial) and aquifer designation status (Principal, Secondary, Unproductive). These maps require that the user is able to understand the vulnerability assessment and interpret the individual components of the legend.

• The simplified groundwater vulnerability map. This was developed for non-specialists who need to know the overall risk to groundwater but do not have extensive hydrogeological knowledge or the time to interpret the underlying data. The map has five risk categories (High, Medium-High, Medium, Medium-Low and Low) based on the likelihood of a pollutant reaching the groundwater (i.e. the vulnerability), the types of aquifer present and the potential impact (i.e. the aquifer designation status). The two maps also identify areas where solution features that enable rapid movement of a pollutant may be present (identified as stippled areas) and areas where additional local information affecting vulnerability is held by the Environment Agency (identified as dashed areas).

Groundwater potentiometric-surface contours for spring 2022 (April 4 to 8, 2022) and autumn 2022 (October 30 to November 4, 2022) were created for the alluvial aquifer in Big Lost River Valley. The well numbers and station names used to create the potentiometric-surface contours and groundwater-level change maps are provided in this data release. The location, depth to water, and potentiometric-surface altitude for these wells can be accessed on USGS National Water Information System (NWIS) or Idaho Department of Water Resources (IDWR) groundwater portal. The interpreted 20-foot contours of the potentiometric-surface are also provided in this data release. The contours are referenced to the North American Vertical Datum of 1988 (NAVD 88). The potentiometric-surface contours are divided into three water-bearing units - shallow, intermediate, and deep - based on well depth, potentiometric-surface altitude, and hydrogeologic unit. The intermediate and deep units were only identified in the southern portion of the valley near Arco, Idaho. The potentiometric-surface contours ranged from 4,900 to 6,660 feet above NAVD 88. The groundwater-level change at well sites from spring to autumn 2022, spring to autumn 1968, spring 1968 to spring 2022, spring 1991 to spring 2022, and spring 1968 to spring 1991 were calculated and are provided in a shapefile.

Spatial coverage index compiled by East View Geospatial of set "Yemen 1:500,000 Groundwater Resources Map". Source data from MOM (publisher). Type: Geoscientific - Energy Resources. Scale: 1:500,000. Region: Middle East.

This is the 2022 version of the Aquifer Risk Map. The 2021 version of the Aquifer Risk Map is available here.This aquifer risk map is developed to fulfill requirements of SB-200 and is intended to help prioritize areas where domestic wells and state small water systems may be accessing raw source groundwater that does not meet primary drinking water standards (maximum contaminant level or MCL). In accordance with SB-200, the risk map is to be made available to the public and is to be updated annually starting January 1, 2021. The Fund Expenditure Plan states the risk map will be used by Water Boards staff to help prioritize areas for available SAFER funding. This is the final 2022 map based upon feedback received from the 2021 map. A summary of methodology updates to the 2022 map can be found here.This map displays raw source groundwater quality risk per square mile section. The water quality data is based on depth-filtered, declustered water quality results from public and domestic supply wells. The process used to create this map is described in the 2022 Aquifer Risk Map Methodology document. Data processing scripts are available on GitHub. Download/export links are provided in this app under the Data Download widget.This draft version was last updated December 1, 2021. Water quality risk: This layer contains summarized water quality risk per square mile section and well point. The section water quality risk is determined by analyzing the long-tern (20-year) section average and the maximum recent (within 5 years) result for all sampled contaminants. These values are compared to the MCL and sections with values above the MCL are “high risk”, sections with values within 80%-100% of the MCL are “medium risk” and sections with values below 80% of the MCL are “low risk”. The specific contaminants above or close to the MCL are listed as well. The water quality data is based on depth-filtered, de-clustered water quality results from public and domestic supply wells.Individual contaminants: This layer shows de-clustered water quality data for arsenic, nitrate, 1,2,3-trichloropropane, uranium, and hexavalent chromium per square mile section. Domestic Well Density: This layer shows the count of domestic well records per square mile. The domestic well density per square mile is based on well completion report data from the Department of Water Resources Online System for Well Completion Reports, with records drilled prior to 1970 removed and records of “destruction” removed.State Small Water Systems: This layer displays point locations for state small water systems based on location data from the Division of Drinking Water.Public Water System Boundaries: This layer displays the approximate service boundaries for public water systems based on location data from the Division of Drinking Water.Reference layers: This layer contains several reference boundaries, including boundaries of CV-SALTS basins with their priority status, Groundwater Sustainability Agency boundaries, census block group boundaries, county boundaries, and groundwater unit boundaries. ArcGIS Web Application

The map shows the location of the six hydrogeological regions in Canada and the location of observation wells. The terrain composition is also shown on the map, which includes crystalline rocks, mixed crystalline rocks, folded sedimentary rocks and flat lying sedimentary rocks. The southern limit of continuous permafrost zone and the limit of the discontinuous permafrost zone appear on the map. Canada has been divided into six hydrogeological regions on the basis of similarities of geology, climate, and topography. These six hydrogeological regions are (1) the Appalachians, covering the area of New Brunswick, Prince Edward Island, Nova Scotia, Newfoundland, and the Gaspé and Eastern Townships of Quebec; (2) the St. Lawrence Lowlands, covering Anticosti Island, the extreme southern area of Quebec, and the southern part of Ontario; (3) the Canadian Shield, lying north of the St. Lawrence Lowlands and extending northward to a line joining the north end of Lake Winnipeg to Anticosti Island; (4) the Interior Plains, lying approximately south of the southern limit of discontinuous permafrost and consisting largely of the southern prairie regions of the provinces of Manitoba, Saskatchewan, and Alberta; (5) the Cordilleran Region, the mountainous part of western Canada within British Columbia; and (6) the Northern Region, approximately covering the area north of the southern limit of discontinuous permafrost. To monitor the groundwater flow systems and fluctuations in these hydrogeological regions a series of groundwater observation wells and piezometers have been established in various parts of Canada, as is shown on the map. The groundwater observation well map indicates the extent of provincial observation well and piezometer networks in Canada. Because of scale limitations, the symbols on the map may indicate more than one well. These wells and piezometers have been established in the southern part of Canada to monitor groundwater fluctuations and may also be used to monitor groundwater quality. Since this region of Canada has the largest population density, groundwater is of more immediate interest here. In the areas of discontinuous and continuous permafrost little has been done at present to monitor groundwater conditions, although this is changing as mineral exploration looks north for new reserves.

This map provides data and information about the major groundwater resources of the world. About 35% of the area of the continents (excluding the Antarctic) is underlain by relatively homogeneous aquifers, 18% is endowed with groundwater, some of which are extensive, in geologically complex regions. Nearly half of the continental areas contain generally minor occurrences of groundwater that are restricted to the near-surface unconsolidated rocks, where groundwater resources are usually sufficient for small to medium-sized population centres.For more information, visit: www.whymap.org

This project consists of 11 files: 1) a zipped folder with a geodatabase containing seven raster files and two shapefiles, 2) a zipped folder containing the same layers found in the geodatabase, but as standalone files, 3) 9 .xml files containing the metadata for the spatial datasets in the zipped folders. These datasets were generated in ArcPro 3.0.3. (ESRI). Six raster files (drainaged, geology, nlcd, precipitation, slope, solitexture) present spatially distributed information, ranked according to the relative importance of each class for groundwater recharge. The scale used for these datasets is 1-9, where low scale values are assigned to datasets with low relative importance for groundwater recharge, while high scale values are assigned to datasets with high relative importance for groundwater recharge. The seventh raster file contains the groundwater recharge potential map for the Anchor River Watershed. This map was calculated using the six raster datasets mentioned previously. Here, the values assigned represent Very Low to Very High groundwater recharge potential (scale 1 - 5, 1 being Very Low and 5 being Very High). Finally, the two shapefiles represent the groundwater wells and the polygons used for model validation. This data is part of the manuscript titled: Mapping Groundwater Recharge Potential in High Latitude Landscapes using Public Data, Remote Sensing, and Analytic Hierarchy Process, published in the journal remote sensing.

A regional map of the water table in the northeastern Tularosa Basin region has been prepared based on elevations of springs and well water levels. Water levels were measured by the New Mexico Bureau of Geology and Mineral Resources from 2009-2011. This map extends up to the western escarpment of the Sacramento Mountains, and is an extension of the water table map of the southern Sacramentos prepared by Land et a l. (2012).

In general, within the area indicated on the map, most ground water flows from east to west following topography. Near the crests of the highest mountains in the region, from the Sierra Blanca mountains to the southern Sacramentos, a ground water divide exists wherein some ground water flows west into the Tularosa Basin region, while the rest flows eastward toward the Pecos Slope. Water flowing west into the Tularosa Basin eventually flows southward.

The aquifer system in the southern Sacramento Mountains is developed primarily within the Yeso Formmation, and the vast majority of water supply wells produce from fractured carbonates, siltstones and mud stones within that rock unit (Land et al., 2012). By contrast, aquifers in the northeastern Tularosa Basin region occur within several different geologic formations with highly variable hydrologic properties. The heterogeneous aquifer system in this area results in part from the fact that the mapped area covers several distinctly different physiographic provinces with differing underlying lithologies. The primary physiographic provinces, which were identified by Mamer et a l. (2014), include the Tularosa Basin, the Carrizozo hilly plain, the northern high mountains (i.e. Sierra Blanca and Nogal Peaks), and the southern high mountains (southern Sacramento Mountains). A significant number of wells are screened in two or more aquifers. The water table represented on this map thus reflects water levels in multiple water-bearing zones, and is intended to show regional ground water patterns and flow paths. Local conditions may deviate from the larger scale, general trends shown on this regional map."

This contains water level data from Open-File Report 561: Regional water table map of the northeastern Tularosa Basin region, Otero and Lincoln counties, New Mexico

Hydrogeological map of the Czech Republic at a scale of 1 : 50,000 is an integral part of the Set of geological and thematic maps and was compiled at the Czech Geological Institute to describe displayed geological environment of each map sheet from the quantitative and partly also qualitative hydrogeological point of view. In an understandable way describes information about groundwater, which is one of the most essential parts of the environmental factors. Hydrogeological map of the Czech Republic 1 : 50,000 provides these basic types of information: - type, character and geometry of the hydrogeological environment (aquifers, aquicludes) - accessibility of groundwater - evaluation of usability of groundwater from the quantitative point of view - evaluation of suitability of groundwater for water supply purposes from the qualitative point of view - possibility of accumulation of groundwater

description: The map graphic image at https://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about 31,000 wells and springs in 49 states compiled by the United States Geological Survey (USGS). The map graphic illustrates an updated version of figure 1 from Ryker (2001). Cited Reference: Ryker, S.J., Nov. 2001, Mapping arsenic in groundwater-- A real need, but a hard problem: Geotimes Newsmagazine of the Earth Sciences, v. 46 no. 11, p. 34-36 at http://www.agiweb.org/geotimes/nov01/feature_Asmap.html. An excel tabular data file, a txt file, along with a GIS shape file of arsenic concentrations (20,043 samples collected by the USGS) for a subset of the sites shown on the map. Samples were collected between 1973 and 2001 and are provided for download.; abstract: The map graphic image at https://water.usgs.gov/GIS/browse/arsenic_map.png illustrates arsenic values, in micrograms per liter, for groundwater samples from about 31,000 wells and springs in 49 states compiled by the United States Geological Survey (USGS). The map graphic illustrates an updated version of figure 1 from Ryker (2001). Cited Reference: Ryker, S.J., Nov. 2001, Mapping arsenic in groundwater-- A real need, but a hard problem: Geotimes Newsmagazine of the Earth Sciences, v. 46 no. 11, p. 34-36 at http://www.agiweb.org/geotimes/nov01/feature_Asmap.html. An excel tabular data file, a txt file, along with a GIS shape file of arsenic concentrations (20,043 samples collected by the USGS) for a subset of the sites shown on the map. Samples were collected between 1973 and 2001 and are provided for download.

The aquifer risk map is being developed to fulfill requirements of SB-200 and is intended to help prioritize areas where domestic wells and state small water systems may be accessing groundwater that does not meet primary drinking water standards (maximum contaminant level or MCL). In accordance with SB-200, the risk map is to be made available to the public and is to be updated annually starting January 1, 2021. The Fund Expenditure Plan states the risk map will be used by Water Boards staff to help prioritize areas for available SAFER funding. This layer contains summarized water quality risk per census block group, square mile section, and well point. The overall census block group water quality risk is based on five risk factors (1. the count of chemicals with a long-term average (20 year) or recent result (within 2 years) above the MCL, 2. the count of chemicals with a long-term average (20 year) or recent result (within 2 years) within 80% of the MCL, 3. the average magnitude or results above the MCL, 4. the percent area with chemicals above the MCL, and 5. the percent area with chemicals within 80% of the MCL). The specific chemicals that contribute to these risk factors are listed as well. Higher values for each individual risk factor contribute to a higher overall score. The scores are converted to percentiles to normalize the results. Higher percentiles indicate higher water quality risk. The water quality data is based on depth-filtered, de-clustered water quality results from public and domestic supply wells, collected following a similar methodology as the Domestic Well Needs Assessment White Paper. The methodology used to calculate the risk percentiles is outlined in the Aquifer Risk Map Methodology. To provide comments or feedback on this map, please email SAFER@waterboards.ca.gov or Emily.Houlihan@Waterboards.ca.gov.Methodology for the draft aquifer risk map available for download.

The Federal Office for the Environment (FOEN) is the body within the Swiss Geological Survey responsible for hydrogeology. The 1:500,000 Hydrogeological Map forms part of the GeoMaps series (GK500) and is divided into two sheets. The first (GK500-Hydro) represents the various groundwater resources in Switzerland and their productiveness. The second (GK500-Hydro_Vul) shows the vulnerability of the groundwater resources to the risk of pollution. The groundwater resources sheet also indicates the type of groundwater aquifer (karstic, jointed or unconsolidated rock), the most important springs and groundwater catchments as well as hydrodynamic information about the infiltration and exfiltration areas. The two sheets were originally published as Tables 8.6 and 8.7 of the Hydrological Atlas of Switzerland HADES (FOEN, 2004 and 2007).