ThIs EA evaluates the potential environmental impact of a DOE proposal that consists of three site development projects at the National Renewable Energy Laboratory’s (NREL) South Table Mountain (STM) site at Golden, Colorado: Construction of the Research Support Facilities (RSF), a new office building or multi-building office complex; Installation of Phase 1 of planned Site Infrastructure Improvements (Phase 1 of Full Site Development); Upgrades to the Thermochemical User Facility (TCUF), TCUF High Bay area, and addition of the Thermochemical Biorefinery Pilot Plant (TBPP).