Emergency Assistance for Rural Water Systems Act of 2021 This bill allows, and provides funds for, the Department of Agriculture (USDA) to provide grants and loans, as well as loan forgiveness, modification, and refinancing, to rural water, wastewater, or waste disposal facilities. Specifically, USDA may provide such assistance for purposes of ensuring public health, safety, and order and to address financial hardships, in particular those due to the COVID-19 (i.e., coronavirus disease 2019) public health emergency.