S. 3591 would authorize the Army Corps of Engineers to construct projects to restore aquatic ecosystems, improve navigation and flood management, and mitigate storm and hurricane damage. The bill also would authorize the Corps to renegotiate the terms of deferred-payment agreements with nonfederal sponsors of eligible projects. Finally, the bill would authorize appropriations for the Environmental Protection Agency (EPA) to provide grants and loans to state and local governments, public water systems, nonprofit organizations, and other entities to support various water infrastructure projects and programs to improve water quality.