Endeavour Historical Photos Aerial view of the PEPCON facility near Henderson, Nevada. The facility operated from 1958-1988. Smoke rising from the former PEPCON plant site after a series of fires and explosions at the facility on May 4, 1988. The in situ bioremediation (ISB) system used for the treatment of perchlorate-impacted groundwater prior to implementation of the current groundwater treatment system. The ISB system was operated from 2006 through 2012 and removed more than 50,000 pounds of perchlorate from groundwater during that time period. Construction of Endeavour's current groundwater treatment system, which began operating in 2012. From left to right: sludge storage tank, clarified water tank, two dissolved air flotation tanks (DAFs), and one sand filter. An influent equalization tank is located behind the DAFs.