Which of the following is NOT a possible ground for closing a food service facility?

The correct answer is based on the understanding of health and safety regulations concerning food service facilities. Hot water availability is crucial for sanitation and food safety practices; without it, a facility cannot ensure proper cleaning of utensils, equipment, and hands, presenting a serious risk to public health. A food-borne illness outbreak is a significant threat that necessitates immediate closure to prevent further spread and protect consumers. Contaminated food is also a direct cause for closure, as serving such food can lead to health risks for customers.

In contrast, high customer ratings do not indicate any health or safety concerns. Positive feedback from customers signifies that the facility is performing well in terms of service, quality of food, and overall experience. Therefore, high customer ratings are not a valid reason to close a food service facility.