Data and model archive used to model and map lithium concentrations in groundwater sources of drinking water in the conterminous United States

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 consist of a Tagged Image File (TIF) raster for each of the 20 model predictor variables and are presented in a zipped folder (Map_Input_Data.zip). The model output consists of 5 TIF raster files for public supply well depths and 5 for domestic supply well depths (presented in the zipped folder Map_Output_Data.zip), which is a probability estimate map for each of the lithium concentration categories plus a map showing the category with the highest probability within each well type.