Standardizing Data for a More Accurate Research Tool
Over the two and a half years it took to create the USGWD, Marston’s team worked with all 50 states and the federal government to comb through groundwater well data. The researchers met with several challenges – while most groundwater wells were created in the last 50-100 years, some records go as far back as the 18th century, and the earliest well in the database dates to 1763. Over the course of time and across state records, the researchers encountered inconsistencies, incompleteness of records and, due to the variety of sources, non-standardized data.
To standardize the records and attempt to fill gaps, the researchers cross-referenced state and county records to resolve discrepancies. They also defined and categorized attributes that were commonly reported across most of the states, pulling disparate yet related data into single groupings. The research included a quality control mechanism that ensured the reliability of the well locations and other critical data points.
To facilitate innovative research and better water management strategies, the database has two datasets: tabular, which includes well location, use and status; and geospatial, which contains location data that have been controlled for quality – excluding, for example, location information that is likely incorrect or incomplete.
Database statistics include:
- Nearly 60% of wells are used for domestic use, irrigation or groundwater monitoring.
- California has the most reported wells of all states (1,164,847), and New Hampshire has the least reported wells of all states (90), highlighting disparities in record keeping across states
- Seventy percent of active wells are in 11 states scattered across the country including California, Ohio, Wisconsin, Michigan, Texas, Florida, Colorado, Maryland, Minnesota and Pennsylvania.
- Well installations increased exponentially after WWII and peaked near 2000.
Scientific Publications
More details about the project can be found in the Nature article, A Database of Groundwater Wells in the United States.