Fast food facilities are known to create the most of which substance?

Fast food facilities are notably associated with the generation of fats, oils, and grease (F.O.G) due to the nature of their food preparation processes. These establishments typically fry foods and utilize various oils for cooking, which contributes to significant quantities of grease entering the waste stream. When these fats and oils are not managed properly, they can cause environmental and infrastructure issues, such as clogging sewer systems and increasing the risk of sewer overflows.

While hazardous waste, light oils, and solid food waste are indeed produced in food service operations, they do not reach the same levels as F.O.G in fast food facilities. Hazardous waste may arise but is generally more regulated and less prevalent than the significant volumes of F.O.G generated. Light oils also do not represent the predominant waste type; they might be noteworthy in other sectors like auto repair but are not primary in fast food. Solid food waste, while substantial, is not as distinctive as the F.O.G characteristic of fast food operations. Therefore, the largest concern and the substance most produced in these contexts is F.O.G, making it the correct answer.