Abstract: At 5:28 p.m. on July 14, 2021, Employee #1 was preparing to enter the facility's external chlorine shed to clean up a broken light bulb. Upon opening the front door, the employee reported smelling chlorine but proceeded to enter and exited through the back door. The employee subsequently felt ill and contacted the facility's Wastewater Supervisor. At approximately 6:14 p.m., the supervisor transported Employee #1 to a hospital in Smyrna, Delaware, and the employee was later transferred and admitted to a hospital in Dover, Delaware. Employee #1 was treated for shortness of breath and released on July 16, 2021, returning to work without restrictions on July 18, 2021.