At the Santa Clara 3 site, the ground water extraction and treatment system was operated until mid-1993, at which time the trichloroethene (TCE) plume had been cleaned up to the extent technically feasible with this technology. The plume footprint remained stable and TCE concentrations slowly decreased after the ground water extraction and treatment system was shutdown. In 2006, Intel voluntarily injected RegenOx, a new oxidizing product, to further reduce the residual TCE at the site. The TCE drinking water standard and cleanup goal for the site is 5 ppb. In 2010, the EPA amended the site Record of Decision (ROD) to specify "Monitored Natural Attenuation" (MNA) as the remedy, indicating that natural processes are expected to restore ground water to drinking water standards within a timeframe that EPA considers reasonable. In attempts to accelerate attainment of drinking water standards, Intel performed targeted groundwater extraction in 2014-2015 and injected PlumeStop, an activated carbon product, in 2016-2017. Concentrations have been reduced to below the cleanup standard and confirmation monitoring is underway. EPA approval for site closure is expected by 2019.