Approximately 5 million people utilize the Ohio River as its drinking water source. The Ohio River Valley Water Sanitation Commission (ORSANCO) as the pollution control agency for the Ohio River and its tributaries, works closely with more than 30 water utilities that utilize this great river as their drinking water supply. Five of these surface water utilities, including Greater Cincinnati Water Works (GCWW), are located in Ohio. In addition, many other groundwater utilities use the river as a source of recharge. The Ohio River serves as an abundant and reliable drinking water source for all of these utilities. However, as with many source waters in the United States, there are source water protection challenges such as chemical spills, on-going discharges, monitoring for regulated and unregulated chemicals, and developing new treatment techniques. At about 8:55 p.m. ET on February 3, 2023, a Norfolk Southern freight train derailed in East Palestine, Ohio, about a quarter-mile west of the Ohio-Pennsylvania state line. Norfolk Southern reported the incident to the National Response Center at 10:53 p.m. and emergency management officials arrived on-site by 2:00 a.m. on February 4. Of the 150 train cars, about 50 cars were affected by the derailment. Twenty of the affected cars contained hazardous materials, including vinyl chloride, ethylene glycol, ethylhexyl acrylate, butyl acrylate and isobutylene. Some cars caught fire. Some cars spilled their loads into an adjacent ditch that feeds Sulphur Run, a stream that joins Leslie Run, which eventually empties into the Ohio River. The spill remnants reached the Ohio River on February 6th at the confluence of the Little Beaver Creek and the Ohio River near the Ohio-Pennsylvania state line. This presentation will detail ORSANCO's successful emergency response efforts to the incident to mitigate the spill's impact on the Ohio River. ORSANCO in partnership with 30 drinking water utilities, Ohio River states, USEPA and numerous other emergency response agencies completed a complex response that included identifying, sampling, and quantifying concentrations of the spill remnant chemicals within the Ohio River. ORSANCO also worked closely with chemists from USEPA, Ohio EPA and the Agency for Toxic Substances and Disease Registry to communicate the health risks associated with these chemicals, quantify the concentrations of these chemicals, track the spill plume and communicate closely with the public. ORSANCO relied heavily on its Organics Detection System that includes 16 pieces of sophisticated laboratory instruments installed at drinking water utilities and industries along the Ohio River, its Ohio River Time of Travel model as well as its highly trained professional emergency response team to help facilitate this successful response. In addition, this presentation detail the public information challenges associated with this spill due to confusing and often incorrect information that was provided through various social media outlets. Lessons learned from this complex source water protection challenge will also be detailed.