A variety of chemical, biological, and radiological contaminants may affect drinking water supplies. Children are especially vulnerable to the effects of contaminants in their water, because they drink more water, eat more food, and breathe more air relative to their size than do adults, and because their bodies are not fully developed and their growing organs can be more easily harmed. This paper describes how state laws and regulations across the U.S. address drinking water quality in child care facilities, which may be served by public water systems or by privately-owned water sources such as wells. The paper provides an overview of the drinking water quality provisions in four types of state policies that may apply to licensed child care facilities – drinking water regulations, food service codes, sanitation codes for child care facilities, and child care licensing laws and regulations.