Oversight support for the closure activities (RCRA units) at Pfizer Arecibo facility. A full time representative from the Puerto Rico licensed Engineer was provided for the oversight of the RCRA units dismantling and demolition activities to observe and document unit decontamination and waste management activities. Engineer-of-Record (EOR) Closure Certification that the facility has been closed in general accordance with the Final Revised RCRA Part B Closure Plan, as approved by the U.S. Environmental Protection Agency (EPA).