The former General Motors manufacturing complex known as Buick City in Flint, Mich., is undergoing a long-term EPA cleanup. The 452-acre facility at 902 Leith St. is divided into the Northend and Southend. Motors Liquidation Co. or MLC, the successor company to the bankrupt General Motors Corp., owns the site. The Buick City complex played a major role in American automotive history with vehicles and parts manufactured there from the 1890s to 1999.
Buick City contains soil and ground water (underground water supplies) contaminated with various petroleum products, chemicals and metals. Some of the ground water under Buick City contains free-floating petroleum product called “light non-aqueous phase liquid” or LNAPL, which is particularly difficult to remove. Parts of Buick City display elevated contamination levels that fail to meet EPA's cancer and noncancerous health standards. The goal of the cleanup projects on Buick City will be to reduce pollution or the exposure to the pollution so redevelopment can safely occur.
Local interest in redevelopment of the Southend prompted officials to focus cleanup efforts there first before the more heavily polluted Northend. In 2010 EPA selected an official cleanup plan for the Southend calling for maintaining parking lots and building slabs as an exposure shield to contaminated on-site soil. In addition, deed restrictions will be placed on the property to warn future construction workers where contamination may be located and to restrict the area to industrial uses. In one part of the Southend, contaminated soil was found off-site on the adjacent CSX Railroad property, and that area of contamination will be excavated. As of early 2011, MLC is negotiating with CSX to gain access to railroad property to begin soil excavation.
The LNAPL pollution remains a challenge. EPA originally believed steam injection would be the best technology to use but has tabled that plan. Instead, the Agency is requiring the responsible party, MLC, to test different innovative technologies to see what works best for each different LNAPL plume. Preliminary activities on these LNAPL recovery and treatment studies began in late 2010 and early 2011 with the collection of soil borings for laboratory tests. Also, in one area where the LNAPL is gasoline, a field test using a technology called multi-phase extraction was performed. At the present time, EPA is evaluating results of that test to see if a full-scale system makes sense.
EPA is currently reviewing a corrective measures proposal for the Northend submitted by MLC. A proposed plan containing EPA's recommended cleanup steps will be released for public comment and a public hearing in late spring/early summer 2011. Meanwhile, decommissioning and demolition of the Northend buildings has started.
Ground water monitoring continues over the entire property. At two storm sewer outlets called Outfalls 3 & 4 a new oil/water separator system has been installed and is operating as an interim measure in order to lessen oil sheens. Ineffective, temporary pollution recovery systems located on Buick City have also been shut down pending construction of long-term cleanup steps.