Estuary Transit District, doing business as River Valley Transit, is the public transit provider for the Lower Connecticut River Valley region. ETD provides bus service through in the municipalities of Chester, Clinton, Durham, Deep River, East Haddam, Essex, Killingworth, Haddam, Lyme, Old Lyme, Old Saybrook, Westbrook, Middlefield, Middletown, and Madison. It was former in 2022 by the merger of the Estuary Transit District and Middletown Area Transit.

Chester is a town in Middlesex County, Connecticut, United States. The town is part of the Lower Connecticut River Valley Planning Region. The population was 3,749 at the 2020 census. The town center is defined by the U.S. Census Bureau as a census-designated place (CDP). The name is a transfer from Chester, in England.