The Gulf States Utilities (GSU)-North Ryan Street site service yard is located at 303 North Ryan Street, Lake Charles, Calcasieu Parish, Louisiana. The facility is situated on the east and west sides of North Ryan Street near the intersection of North Ryan Street and River Road. GSU-North Ryan Street consists of the west service yard (west of N. Ryan St.) and the east yard (east of N. Ryan St.) which total approximately 19 acres.

The GSU-North Ryan Street facility has been in operation since 1926. Prior to 1926, the property was occupied by the Lake Charles Gas Company. Coal gasification operations by the gas company resulted in an unknown quantity of coal tar which was deposited in the adjacent wetland area. After the property was purchased in 1926, GSU-North Ryan Street began to utilize the wetland area, then encompassing 6 acres, as a landfill for waste materials associated with the North Ryan Street facility's operation, such as for the disposal of electrical poles and equipment, debris, appliance carcasses and miscellaneous items. According to a former employee, used transformer oils and transformers were routinely dumped into the landfill area. By 1980, the landfill was filled to capacity and covered with shells and soil. In at least one area, the covering has subsided or been breached, and a tar seep covering approximately 64 square feet is present. This area was identified in 1988 during an inspection conducted by the Louisiana Department of Environmental Quality (LDEQ).

In September 1988, LDEQ issued a compliance order to GSU to conduct remedial activities at the GSU-North Ryan Street site. Studies were conducted by GSU beginning in December 1988 and continuing through October 1990. EPA conducted a site inspection (SI) at the site which included sampling activities during the week of October 1, 1990 and the completion of an SI report in September of 1992. Samples collected during SI field activities from Calcasieu River sediments revealed that contaminants attributable to the GSU-North Ryan Street facility were being released to the Calcasieu River. Specifically, the contaminants of concern to the surface water are polyaromatic hydrocarbons, copper, and lead.