The North East 2nd Street Superfund site in Happy, Texas, overlies a groundwater plume of primarily carbon tetrachloride (CT) that is contained within an upper transmissive zone of the High Plains aquifer system (hereinafter referred to as the "Ogallala aquifer"). The Ogallala aquifer is contained in Tertiary-age sediments of the Ogallala Formation in the study area, which are described by Nordstrom and Fallin (1989, p. 10) as "tan, yellow, and reddish-brown, silty to coarse-grained sand mixed or alternating with yellow to red silty clay and variable sized gravel." The plume originated from the application of fire-retardant chemicals (including CT) onto the ground surface during the extinguishing of a fire at a grain storage elevator in 1962. As of 2022, the plume was 60 years old and extended approximately two-thirds of a mile downgradient (northeast) from the site of the fire. No hydraulic controls or boundaries are evident at the leading edge of the plume to constrain its further transport, and center-pivot irrigated agriculture and concentrated animal feeding operations are immediately downgradient across Interstate Highway 27. Because minimal sampling data have been collected, the question of whether the plume has reached a state of equilibrium is unknown. Slug tests were performed in cooperation with the U.S. Environmental Protection Agency at 10 monitoring wells during January 7–8, 2025, including some of the newly-drilled wells in addition to some preexisting wells that had not been tested previously. Estimated hydraulic conductivities ranged from 0.05 to 410 feet per day (ft/day) in the 10 wells tested in 2025.
