Most street vendor food and beverage carts would be regulated as Pushcarts by the ECDOH, and would be required to comply with NYS Sanitary Code Subpart 14-4.
Subpart 14-4.141 requires pushcarts to"...have handwashing facilities for the operator. This handwashing facility is to be a supply of clean, potable water, soap or detergent, a receptacle to hold waste water, and paper towels." This would be the only "sink" required to be on the pushcart.
However, the code (14-4.31(b)) also requires pushcarts to be operated in conjunction with a Mobile Food Service Establishment Commissary which "...is used as the base of operations for one or more...pushcarts, where such unit or units are serviced, cleaned, supplied, maintained, and where the equipment, utensils and facilities are serviced, cleaned and sanitized." This commissary is required to have additional sinks (such as a 3-basin sink for manual warewashing of pans, utensils, etc.) and other equipment/facilities (storage, bathrooms, etc.) that the pushcart operator would use before and after the pushcart was taken to the foodservice location.