Which agency is responsible for ensuring safe drinking water under the Safe Drinking Water Act?

The agency responsible for ensuring safe drinking water under the Safe Drinking Water Act is the Environmental Protection Agency (EPA). This act was established to protect public health by regulating the nation's public drinking water supply. The EPA sets standards for water quality and oversees states, localities, and water suppliers to ensure compliance with these standards. This includes monitoring contaminants, enforcing regulations, and providing necessary guidance to maintain the safety and quality of drinking water.

Other agencies, although related to health and environmental regulation, have different primary responsibilities. The FDA is mainly focused on food safety and the regulation of food products, while the CDC is involved in public health and disease control but does not manage water quality standards directly. The USGS primarily conducts scientific research and provides data on natural resources, including the hydrology of the water supply, but it does not enforce drinking water regulations. Thus, the EPA is the correct agency for enforcing the provisions of the Safe Drinking Water Act.