Groundwork USA Trust Act of 2013 - Establishes the Groundwork USA Trust Program.
Authorizes the Secretary of the Interior to award grants to eligible nonprofit organizations to: (1) facilitate the inventory of brownfield sites, site assessments, remediation of brownfield sites, community involvement, or site preparation; (2) reclaim vacant and derelict lands; (3) cleanup and care for neglected areas; (4) return brownfields to productive use; (5) integrate environmental education, food security, health and fitness, resource management, and job training; (6) encourage and support business, local government, nonprofit, and community cooperation in sustainable environmental care and enhancement; (7) acquire, rehabilitate, and improve real property and buildings; and (8) develop programs that encourage partnering with other environmental organizations.