The Rhode Island Sound Disposal Site (RISDS) was designated in December 2004. This 3.24 km2 (1 nautical mi2) site is centered at 41° 13.850' N, 71° 22.817' W (NAD 83) and lies approximately 21 km south of the entrance to Narragansett Bay, Rhode Island. It is situated within the Separation Zone for the Narragansett Bay Inbound and Outbound Traffic Lanes and lies within a topographic depression, with water depths from 36 to 39 m. Prior to its site designation, it was selected for temporary use and was employed during 2003-2004 for placement of over 3.4 million m3 (4.5 million yd3) of sediment from the Providence River (primarily from the Federal Navigation Project). The management strategy during the Providence project was to dispose at a carefully selected series of north-south-trending points in order to create a continuous ridge of sediment along the western edge of the site. This ridge created an artificial containment structure along the western boundary of the disposal site in order to minimize lateral spread of unconsolidated sediments deposited in the future. A total of 5,311,963 yd3 has been disposed of at this site since 2003.