United States Environmental Protection Agency is responsible for affairs concerning pollution abatement. The agency conducts research on a number of topics, such as land/sediments and waste management, land use and watershed protection. It offers a nationwide radiation monitoring system, RadNet, which continuously monitors the air quality and regularly monitors drinking water, milk and precipitation for environmental radiation in the United States. The agency also conducts research to protect human health and the environment in support of the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA).