Data used to model and map pH and redox conditions in groundwater in the Northern Atlantic Coastal Plain aquifer system, eastern USA, are documented in this data release. The models use as input data measurements of pH and dissolved oxygen concentrations at about 3000 to 5000 wells, which were compiled primarily from U.S. Geological Survey and U.S. Environmental Protection Agency databases. The boosted regression trees machine learning method was used to build the models. Explanatory variables (predictors) describe geology, hydrology, chemistry, physical characteristics, anthropogenic influence, metrics from a groundwater flow model, and groundwater residence times in the aquifer system. Data for four models are documented--one model for pH and one model each for the probability of dissolved oxygen less than three threshold values (0.5, 1, and 2 milligrams per liter). The data are provided in data tables and raster files, organized as follows. There is one data table for the well data used to develop all four models (well data). There is one zipped group of 10 files (one for each aquifer) for explanatory input data used to make predictions at grid points (prediction input). There are 9 zipped groups of files for model output; these include 1 zip file of predictions at grid points for each of the 4 models (prediction output), 1 zip file for combined pH and dissolved oxygen predictions (combined prediction output); and 4 zip files of uncertainty intervals for predictions for each of the 4 models (uncertainty output). Filenames for prediction input and for model output are distinguished by codes abbreviating the aquifer name and position in the vertical stack of 19 regional aquifers and confining units, as follows: Surficial aquifer, 1surf; Upper Chesapeake aquifer, 3upch; Lower Chesapeake aquifer, 5loch; Piney Point aquifer, 7pipt; Aquia aquifer, 9aqia; Monmouth - Mt. Laurel Aquifer, 11moml; Matawan aquifer, 13mtwn; Magothy Aquifer, 15mgty; Potomac-Patapsco aquifer, 17popt; Potomac-Patuxent aquifer, 19popx. The data release also contains a tif-format raster file of the prediction grid and two data tables that separately describe the explanatory variables (predictors) and their sources.

This data release contains input data used in model development and TIF raster files used to predict the probability of low dissolved oxygen (DO) and high dissolved iron (Fe) in groundwater within the glacial aquifer system in the northern continental United States. Input data include measured DO and Fe concentrations at groundwater wells, and associated predictor variable data. The probability of low DO and high Fe was predicted using boosted regression tree methods using the gbm package in R (v. 4.0.0) in RStudio (v. 1.2.5042). The response variables for individual models were the occurrence of: (1) DO ≤0.5 mg/L, (2) DO ≤2 mg/L, and (3) Fe >100 µg/L. Water-quality data were compiled from three sources, as described in Wilson and others (2019): a compilation of data from numerous agencies and organizations at the state, regional, and local level; the U.S. Geological Survey National Water Information System; and the U.S. Environmental Protection Agency Safe Drinking Water Information System. The resultant datasets consisted of 9,398 DO and 17,422 Fe measurements across the study area. A total of 108 predictor variables were originally considered for model development which included well characteristics, soil properties, aquifer properties, predicted nitrate, hydrologic position on the landscape, and groundwater age. After model refinement, a total of 86, 94, and 40 predictor variables were used for predicting the probability of low DO (0.5 and 2 mg/L) and high Fe, respectively.

This data release contains input data used in model development and TIF raster files used to predict the probability of low dissolved oxygen (DO) and high dissolved iron (Fe) in groundwater within the glacial aquifer system in the northern continental United States. Input data include measured DO and Fe concentrations at groundwater wells, and associated predictor variable data. The probability of low DO and high Fe was predicted using boosted regression tree methods using the gbm package in R (v. 4.0.0) in RStudio (v. 1.2.5042). The response variables for individual models were the occurrence of: (1) DO ≤0.5 mg/L, (2) DO ≤2 mg/L, and (3) Fe >100 µg/L. Water-quality data were compiled from three sources, as described in Wilson and others (2019): a compilation of data from numerous agencies and organizations at the state, regional, and local level; the U.S. Geological Survey National Water Information System; and the U.S. Environmental Protection Agency Safe Drinking Water Information System. The resultant datasets consisted of 9,398 DO and 17,422 Fe measurements across the study area. A total of 108 predictor variables were originally considered for model development which included well characteristics, soil properties, aquifer properties, predicted nitrate, hydrologic position on the landscape, and groundwater age. After model refinement, a total of 86, 94, and 40 predictor variables were used for predicting the probability of low DO (0.5 and 2 mg/L) and high Fe, respectively.

A digital model of the sedimentary Northern Atlantic Coastal Plain aquifer system is composed of 20 rasters and hydrogeologic unit extent polygons. Rasters describe the top elevations of regional aquifers and confining units at a resolution of 2640 feet (1/2 mile). The rasters are clipped to the extent polygons, which represent the spatial extents of the hydrogeologic units onshore and several miles offshore. This three-dimensional hydrogeologic model was constructed as part of a U.S. Geological Survey Groundwater Resources Program study of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system, including parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. Digital elevations of major regional aquifers and confining units were compiled from published digital elevation models (DEM) of various parts of the NACP aquifer system to provide a consistent regional model of hydrogeologic unit geometries. The many studies incorporated within these data include the interpretation and analysis of thousands of well logs and other related information spanning at least a century of study. These regional units are derived from published unit-elevation contours interpreted by geologists at the state and local level, and incorporate little additional interpretation of unit elevations beyond the correlation of individual units across geographic boundaries and some extrapolation of units to the edges of the modeled area. This regionally consistent hydrogeologic framework was used as the foundation of a MODFLOW groundwater flow model of the NACP, which informed modifications to the regional hydrogeologic units that have now been incorporated into the framework data. A related digital elevation model (DEM) for the Northern Atlantic Coastal Plain (NACP) from Long Island New York to northeastern North Carolina represents the elevation of the topographic and bathymetric surface at a uniform horizontal grid spacing of 100 feet and vertical units of 1 (integer) foot. The land-surface elevations are derived from U.S. Geological Survey 30-meter National Elevation Dataset (NED), and the bathymetric elevations are derived from 3 arc-second (90-meter-nominal) National Oceanic and Atmospheric Administration (NOAA) U.S. Coastal Relief Model (CRM).

A digital model of the sedimentary Northern Atlantic Coastal Plain aquifer system is composed of 20 rasters and hydrogeologic unit extent polygons. Rasters describe the top elevations of regional aquifers and confining units at a resolution of 2640 feet (1/2 mile). The rasters are clipped to the extent polygons, which represent the spatial extents of the hydrogeologic units onshore and several miles offshore. This three-dimensional hydrogeologic model was constructed as part of a U.S. Geological Survey Groundwater Resources Program study of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system, including parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. Digital elevations of major regional aquifers and confining units were compiled from published digital elevation models (DEM) of various parts of the NACP aquifer system to provide a consistent regional model of hydrogeologic unit geometries. The many studies incorporated within these data include the interpretation and analysis of thousands of well logs and other related information spanning at least a century of study. These regional units are derived from published unit-elevation contours interpreted by geologists at the state and local level, and incorporate little additional interpretation of unit elevations beyond the correlation of individual units across geographic boundaries and some extrapolation of units to the edges of the modeled area. This regionally consistent hydrogeologic framework was used as the foundation of a MODFLOW groundwater flow model of the NACP, which informed modifications to the regional hydrogeologic units that have now been incorporated into the framework data.

A digital model of the sedimentary Northern Atlantic Coastal Plain aquifer system is composed of 20 rasters and hydrogeologic unit extent polygons. Rasters describe the top elevations of regional aquifers and confining units at a resolution of 2640 feet (1/2 mile). The rasters are clipped to the extent polygons, which represent the spatial extents of the hydrogeologic units onshore and several miles offshore. This three-dimensional hydrogeologic model was constructed as part of a U.S. Geological Survey Groundwater Resources Program study of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system, including parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. Digital elevations of major regional aquifers and confining units were compiled from published digital elevation models (DEM) of various parts of the NACP aquifer system to provide a consistent regional model of hydrogeologic unit geometries. The many studies incorporated within these data include the interpretation and analysis of thousands of well logs and other related information spanning at least a century of study. These regional units are derived from published unit-elevation contours interpreted by geologists at the state and local level, and incorporate little additional interpretation of unit elevations beyond the correlation of individual units across geographic boundaries and some extrapolation of units to the edges of the modeled area. This regionally consistent hydrogeologic framework was used as the foundation of a MODFLOW groundwater flow model of the NACP, which informed modifications to the regional hydrogeologic units that have now been incorporated into the framework data.

A digital model of the sedimentary Northern Atlantic Coastal Plain aquifer system is composed of 20 rasters and hydrogeologic unit extent polygons. Rasters describe the top elevations of regional aquifers and confining units at a resolution of 2640 feet (1/2 mile). The rasters are clipped to the extent polygons, which represent the spatial extents of the hydrogeologic units onshore and several miles offshore. This three-dimensional hydrogeologic model was constructed as part of a U.S. Geological Survey Groundwater Resources Program study of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system, including parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. Digital elevations of major regional aquifers and confining units were compiled from published digital elevation models (DEM) of various parts of the NACP aquifer system to provide a consistent regional model of hydrogeologic unit geometries. The many studies incorporated within these data include the interpretation and analysis of thousands of well logs and other related information spanning at least a century of study. These regional units are derived from published unit-elevation contours interpreted by geologists at the state and local level, and incorporate little additional interpretation of unit elevations beyond the correlation of individual units across geographic boundaries and some extrapolation of units to the edges of the modeled area. This regionally consistent hydrogeologic framework was used as the foundation of a MODFLOW groundwater flow model of the NACP, which informed modifications to the regional hydrogeologic units that have now been incorporated into the framework data.

A digital model of the sedimentary Northern Atlantic Coastal Plain aquifer system is composed of 20 rasters and hydrogeologic unit extent polygons. Rasters describe the top elevations of regional aquifers and confining units at a resolution of 2640 feet (1/2 mile). The rasters are clipped to the extent polygons, which represent the spatial extents of the hydrogeologic units onshore and several miles offshore. This three-dimensional hydrogeologic model was constructed as part of a U.S. Geological Survey Groundwater Resources Program study of groundwater availability in the Northern Atlantic Coastal Plain (NACP) aquifer system, including parts of New York, New Jersey, Delaware, Maryland, Virginia, and North Carolina. Digital elevations of major regional aquifers and confining units were compiled from published digital elevation models (DEM) of various parts of the NACP aquifer system to provide a consistent regional model of hydrogeologic unit geometries. The many studies incorporated within these data include the interpretation and analysis of thousands of well logs and other related information spanning at least a century of study. These regional units are derived from published unit-elevation contours interpreted by geologists at the state and local level, and incorporate little additional interpretation of unit elevations beyond the correlation of individual units across geographic boundaries and some extrapolation of units to the edges of the modeled area. This regionally consistent hydrogeologic framework was used as the foundation of a MODFLOW groundwater flow model of the NACP, which informed modifications to the regional hydrogeologic units that have now been incorporated into the framework data. A related digital elevation model (DEM) for the Northern Atlantic Coastal Plain (NACP) from Long Island New York to northeastern North Carolina represents the elevation of the topographic and bathymetric surface at a uniform horizontal grid spacing of 100 feet and vertical units of 1 (integer) foot. The land-surface elevations are derived from U.S. Geological Survey 30-meter National Elevation Dataset (NED), and the bathymetric elevations are derived from 3 arc-second (90-meter-nominal) National Oceanic and Atmospheric Administration (NOAA) U.S. Coastal Relief Model (CRM).

Data used to model and map manganese concentrations in groundwater in the Northern Atlantic Coastal Plain (NACP) aquifer system, eastern USA, are documented in this data release. The model predicts manganese concentration within four classes and is based on concentration data from 4492 wells. The well data were compiled from U.S. Geological Survey, U.S. Environmental Protection Agency, Suffolk County Water Authority (Suffolk County, New York), and state agency sources. The four concentration classes are based on guidelines for drinking water quality: below detection (class 1, less than 10 micrograms per liter (ug/L)); detected but less than the aesthetic guideline of 50 ug/L (class 2); greater than the aesthetic guideline but less than the health guideline of 300 ug/L (class 3); and greater than the health guideline of 300 ug/L (class 4). The thresholds of 50 ug/L and 300 ug/L are a Secondary Maximum Contaminant Level and a lifetime health advisory, respectively, from the U.S. Environmental Protection Agency for public water supplies. The model is built with the XGboost machine learning method. Explanatory variables (predictors) include well depth, soil characteristics, hydrologic variables, groundwater residence time, and predicted values of pH and of the probability of low dissolved oxygen from previous machine learning models of the aquifer system. The data are provided in data tables, raster files, and model files, organized as follows. One data table describes the 27 explanatory variables used in the model (NACP_Mn_explanatory_variables.csv). There is a data table for the well data used to develop the models, which includes the manganese concentrations, concentration classes, regional aquifer, explanatory variables, and predicted concentration class for the wells (NACP_Mn_well_data.csv). There is a compressed group (zip file) of 10 files (one for each regional aquifer) for explanatory variable data used to make predictions for the regional aquifers (NACP_Mn_prediction_input_aquifers.zip). There are two zip files providing model output, one for predictions made for each aquifer in text format and one for tif-format rasters of predictions for each aquifer. The data release also contains a tif-format raster file of the prediction grid and a zip file with the model object file (R data format) and a script that can be used to run the model to produce the predictions provided in this data release. Filenames for prediction input and for model output are distinguished by codes abbreviating the aquifer name and position in the vertical stack of 19 regional aquifers and confining units, as follows: Surficial aquifer, 1surf; Upper Chesapeake aquifer, 3upch; Lower Chesapeake aquifer, 5loch; Piney Point aquifer, 7pipt; Aquia aquifer, 9aqia; Monmouth - Mt. Laurel Aquifer, 11moml; Matawan aquifer, 13mtwn; Magothy Aquifer, 15mgty; Potomac-Patapsco aquifer, 17popt; Potomac-Patuxent aquifer, 19popx. The nine confining units are not represented in the model or predictions.

This data set represents the extent of the North Atlantic Coastal Plain aquifer system in North Carolina, Virginia, Maryland, Deleware, and New Jersey.