EFFECTIVE DIGITALIZATION OF WELL RECORDS TO CREATE A GROUNDWATER RESOURCE MANAGEMENT TOOL IN THE STATE OF CONNECTICUT

There are around 322,578 private residential wells in Connecticut. A well completion report is submitted to the state every time a new well is constructed or existing well is modified. Up to this year, the public well data repository consisted of scanned records in the form of TIF files for each well completion report dating back to the 1970s. However, these records cannot be queried. The files are organized by their township and the year they were filed, making it difficult to find information from a specific address or to compile a number of data points in an area of interest. In this study about 1,700 well completion reports from a Connecticut township were digitalized into a MS Access database. Among the 30+ fields that were digitalized from each form, most records contained information for the following: permit number, date of well completion, house number, street name, depth from ground surface to the bedrock, depth to water, geologic descriptions, well casing depth, total well depth, and well yield. For wells completed prior to street address assignments, lot numbers were typically indicated. After all records were entered and checked for errors, these fields were queried and imported into ArcGIS to develop a geodatabase for hydrogeologic assessments. Records with street addresses were geolocated to approximate the well coordinates. The township’s GIS parcel viewer was used to manually identify the address for records that only contained lot numbers. After coordinates were obtained for each record, spatial analyses could be performed on the dataset. Raster surfaces for potentiometric elevation, bedrock topography, overburden thickness, and groundwater flow boundaries were generated using the spatial analyst toolset. This study is a demonstration of how additional digitalization of historic well records throughout the entire state would be beneficial in assessing bedrock depth, bedrock recharge areas, groundwater depth and flow direction, and bedrock aquifer transmissivity. Such assessments would be helpful in dealing with water supply and contamination related issues.