Background/ History
Sigma-Aldrich Inc.’s DeKalb facility is located on 7 acres at 3500 DeKalb St. in St. Louis. The operating portion of the site is approximately 3 acres. From 1895 to 1955, the property was owned by Medart Patent Pulley Co. and used to manufacture various steel and cast iron products such as steel rim, pulleys and couplings. In 1956, the property was acquired by Midwest Consultants Co., a predecessor to Sigma Chemical Co. Sigma manufactured biochemicals, cosmetics, shoe dressings, adhesives and inks for cardboard packaging, and corrosion resistant paints. These operations were discontinued in the late 1950’s when construction of I-55 claimed a building at the facility. Manufacturing, processing, packaging, storage, and labeling of research biochemicals expanded. The facility is currently operated by Sigma-Aldrich Manufacturing LLC, and owned by a related company.
A variety of hazardous wastes are produced as part of the facility operations. Sigma stored the hazardous waste in tanks and drums before shipping off-site for disposal. Sigma operated the hazardous waste storage area under a department-issued hazardous waste permit, effective Sept. 14, 1984. The facility no longer stores hazardous waste at the site for more than 90 days. The containers are managed under generator storage requirements in 10 CSR 25-5.
Cleanup Summary
Sigma closed the waste container and waste tank storage areas according to their department-approved closure plan. The department accepted Sigma’s closure certification for the hazardous waste storage areas in 1996. Sigma is not subject to the permitting requirements of the Missouri Hazardous Waste Management Law or federal Hazardous and Solid Waste Amendments for post-closure care because they “clean closed” the interim status hazardous waste areas.
According to applicable state and federal hazardous waste laws and regulations, Sigma is required to investigate and clean up releases of hazardous waste and hazardous constituents to the environment at their facility resulting from present and past hazardous waste handling practices. Sigma is subject to corrective action, but is not subject to issuance or reissuance of a hazardous waste permit, because their original permit was issued before the effective date of the federal Hazardous and Solid Waste Amendments and did not contain any corrective action conditions. Initial investigations in the mid-1990s identified several areas that required further investigation. Sigma conducted a RCRA Facility Investigation and a preliminary Corrective Measure Study to define the horizontal and vertical extent of any contamination. These reports were submitted in 1999 and 2000. A Deed Notice, signed by the City of St. Louis Recorder of Deeds in 1996, was placed on 4.67 acres of the site in order to inform potential future buyers of the property that these areas at the facility had residual contamination. In September 2007, the department and Sigma voluntarily entered into a Letter of Agreement, in an effort to simplify and streamline the corrective action process. Sigma is conducting a RCRA Facility Investigation to define the horizontal and vertical extent of any contamination. If any corrective action activities are necessary, they will be based on the investigation results.
