A dataset describing well water metal/metalloid contamination of private wells in North Carolina, 1998-2019

Well water tests from October 19, 1998 to May 20, 2019 conducted by the NC Department of Health and Human Services (NC DHHS) State Laboratory for Public Health were compiled. These data underwent quality assessment and control protocols, and were geocoded resulting in a dataset of n=117,960 well water test reports, spanning all 100 counties and 89% of census tracts. County-level and census tract-level descriptive statistics and number (and percentage) of exceedances of federal and state standards were calculated for 28 different metals/metalloids. The included metals/metalloids are: aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, calcium, chromium, cobalt, copper, hexavalent chromium, iron, lead, magnesium, manganese, mercury, molybdenum, nickel, potassium, selenium, silver, sodium, strontium, thallium, uranium, vanadium, zinc. A total of three datasets are presented herein: Dataset #1: County-level distributions of the included 28 metals/metalloids as well as nitrites and nitrates derived from Dataset #1; Dataset #2: Census tract-level distributions of the included 28 metals/metalloids as well as nitrites and nitrates derived from Dataset #1; Dataset #3: Relevant standards and screening levels for metals/metalloids in NC groundwater as of July 2021. Each dataset is accompanied with a detailed codebook.