The Superfund program enters into agreements with a number of States, organizations and companies to help EPA fulfill its mission of cleaning up hazardous waste sites and responding to emergencies. Much of the work under Superfund is performed by private contractors. Through extramural funding agreements, which include contracts, grants, cooperative agreements, and interagency agreements, EPA ensures that all required Superfund cleanup work will be performed. Scopes of these agreements range from initial site assessments to remedy implementation both for Fund-lead, Federal Facility-Lead, and Potentially Responsible Party Lead actions. These agreements also support emergency response planning and preparedness and provide technical and construction assistance in emergencies of national significance. In Region 4, the Superfund Support Branch is responsible for the implementation of contracts for all Superfund programs.