MODFLOW 6 and MODPATH 7 model data sets used to evaluate groundwater flow in the vicinity of Horsham and Warminster, Bucks and Montgomery Counties, Pennsylvania-Preliminary simulations for conditions in 1999, 2010, 2013, 2016, and 2017

In cooperation with the U.S. Navy, USGS developed and calibrated a numerical MODFLOW 6 model to simulate regional groundwater flow under selected conditions during 1999-2017 at and near the former Willow Grove Naval Air Station Joint Reserve Base in Horsham, Montgomery County and the former Naval Air Warfare Center Warminster in Bucks County, Pennsylvania. The model simulations provide information on regional groundwater-flow paths and groundwater/surface-water exchanges, in relation to changes in water supply pumping and recharge rates. Groundwater flow paths were simulated using MODPATH 7 from possible PFAS sources at the former bases under steady-state conditions for years 1999, 2010, 2013, 2016, and 2017. This USGS data release contains all of the input and output files for the model calibration and simulations described in the associated report https://doi.org/10.3133/ofr20191137.