Water-level data and selected field notes for aquifer-interval-isolation tests at and near the former Naval Air Warfare Center Warminster, Bucks County, Pennsylvania, 2018-19

The U.S. Geological Survey (USGS) conducted aquifer interval isolation (packer) tests of discrete water-bearing zones using straddle packers in 13 wells in Northampton, Warminster, and Warwick Townships and Ivyland Borough, Bucks County, Pennsylvania during 2018-19 to support detailed groundwater investigations at and near the former Naval Air Warfare Center (NAWC) Warminster, where groundwater contamination with per- and polyfluoroalkyl substances (PFAS) had become a concern since 2014. The area is underlain by the Triassic-age Stockton Formation, which forms a fractured-sedimentary-rock aquifer used for private, industrial, and public drinking-water supply. The packer tests were conducted in 7 former production wells ranging in depth from 160 to 604 feet (ft) near NAWC Warminster and 6 new monitoring wells drilled in 2018 to depths of about 600 ft. on NAWC Warminster. The tested intervals were selected using geophysical and video logs previously collected by USGS to characterize the boreholes and identify potential water-bearing fractures. During the packer tests, water levels in intervals above the upper packer, within the straddled (mid) interval, and below the lower packer were measured during packer inflation, pumping, recovery, and packer deflation. Pumping rates and sampling times were noted.