The U.S. Department of Energy (DOE) prepared an environmental assessment (EA) that evaluates the potential environmental impacts of upgrading the Stanford Positron-Electron Asymmetric Ring (SPEAR) at the Stanford Linear Accelerator Center (SLAC) (DOE/EA-1243). The proposed upgrade, called SPEAR3, would result in a substantial improvement in capabilities on all of the SPEAR experimental stations, or beamlines, and would have a significant positive impact on the current and future science and technology program of SLAC’s Stanford Synchrotron Radiation Laboratory (SSRL).