Healthy Drinking Water Affordability Act or the Healthy H2O Act This bill directs the Department of Agriculture (USDA) to establish a program under which USDA awards grants for improving the quality of drinking water in certain rural areas. Grants may be given to individuals or entities, such as home owners, renters, and licensed child-care facilities, that have demonstrated the presence of one or more health contaminants in their drinking water. Grants may also be given to nonprofit organizations to help individuals and entities test their water, analyze the results of the tests, and reduce the contamination.