Portable hand sinks offer the convenience of hot and cold water for prep work, cleanup, and hand washing where plumbing isn't available. These self-contained, mobile carts are designed to either have removeable tanks for a fresh water supply and wastewater storage or hose-connections for an external supply of water. Some portable sink models require access to an external power supply. Models may include soap dispensers, paper towel holders, or a water heater to provide hot water. Portable hand sinks are commonly used in public spaces such as farmer's markets, festivals, and outdoor food vendors.