The Weyerhaeuser Plymouth Mill facility (Mill) is an active wood and paper products manufacturing facility located on State Road 1565 in Martin County, North Carolina. Weyerhaeuser Paper Company has been the owner/operator of this facility since 1957, when the company merged with the Kieckhefer-Eddy Company, which began operations at the facility in 1937. The facility is situated on about 2,400 acres near the confluence of Welch Creek and the Roanoke River, about 1.5 miles from the Town of Plymouth and approximately 7 miles upstream from Albemarle Sound. The Site includes four Operable Units (OUs) adjacent to or on the Site: OU1, landfill #1; OU2, the Lower Roanoke River; OU3, the former chlorine plant; and OU4, Welch Creek. The landfill (OU1) and former chlorine plant (OU3) are located on the Site property and are currently undergoing remediation. Welch Creek (OU4), a tributary to the lower Roanoke River (OU2), flows through the eastern portion of the Site for approximately 4.1 miles. The Roanoke River is the northern boundary of the Site.

Since 1937, Welch Creek and the Roanoke River received wastes from the Site containing contamination including dioxins, furans, and mercury. As a result of contaminant discharges from this and other sites in the area, Welch Creek and the lower Roanoke River have had a State imposed fish consumption advisory due to dioxin since 1990. Western Albemarle Sound was added to this advisory in 1991. A fish consumption advisory for mercury was imposed for all State waters east of I-85 in 1997 and expanded to include all State waters in 2006.