The CMC Heartland Lite Yard Site (Site) is located in Minneapolis, Minnesota at the northwest intersection of Hiawatha Avenue and 28th Street. The Site is approximately five acres in size. Records show that Reade Manufacturing Company, an arsenical pesticide manufacturer, had leased and operated on the Site for nearly twenty-five years, from early 1938 to 1963. US Borax sub-leased the land from 1963 to 1968, and stored product at the Site during that time. Contamination was discovered in 1994 during reconstruction of the Hiawatha Avenue corridor.
By 1996, the Site was covered with one to two feet of crushed asphalt and clean fill. The Site was vacant and the covering remained intact until the 2004 site cleanup was initiated. The cover kept dust from blowing off the Site until the cleanup was conducted.
The Agency for Toxic Substances and Disease Registry (ATSDR), in conjunction with the Minnesota Department of Health (MDH), provided two Health Consultations dated April 8, 1999 and May 17, 2001. These Health Consultations expressed a concern about the possibility of highly contaminated dust being windblown off the Site, and noted that no sampling had been done in the residential area located about fifty or more meters northwest of the Site.
In June 2001, MDA and MDH conducted a limited soil investigation in the residential yards west and northwest of the Site to determine if elevated levels of arsenic were present. A follow-up investigation, using EPA Data Quality Objectives, was conducted in September 2003. The results of these studies indicated that approximately 15 percent of the properties near the Site may have elevated levels of arsenic that could pose a health risk to children if ingested.
The Minnesota Department of Agriculture (MDA) asked the US Environmental Protection Agency (EPA) in January 2004 to review the data and address the issues in the Phillips neighborhood.
EPA has since conducted three additional soil sampling events in the surrounding neighborhoods beginning in 2004. By 2006 approximately 4000 properties had been sampled for arsenic within ¾ mile of the site, and in 2007 the Neighborhood Site was added to the National Priority List (NPL) of Superfund sites.
In 2004 the EPA initiated Removal Actions in the residential neighborhoods to address acute concentrations of arsenic (> 95 ppm). These actions will continue in 2008. In addition, the EPA is preparing to expand residential property cleanups to residential properties with < 95 ppm arsenic down to a lower concentration. For information on the EPA residential cleanups please go to CMC Heartland from Environmental Protection Agency.
Two remaining Responsible Parties for the Site, CMC Heartland Partners of Chicago, Illinois and U.S. Borax, performed investigations of both the Site soil and ground water from 1995 through 2006. The investigations defined the varying levels of arsenic in the soil on the Site. Surface samples ranged from background levels to 5200 mg/kg. Cleanup began in Fall of 2004 and was completed in 2005. Alternative 5 was chosen for the cleanup approach, which is detailed in the fact sheet entitled Proposed Plan for Cleanup at the CMC Heartland Lite Yard Site (PDF: 2.4MB / 8 pages). Approximately 62,000 cubic yards of arsenic contaminated soil and debris were excavated from the site. An office/warehouse was constructed on the site in 2005-2006. The current property owner is monitoring arsenic contamination in the ground water in the uppermost glacial and bedrock formations beneath and adjacent to the site.
Greg Hanson, Project Manager
Cathy Villas-Horns, Project Hydrogeologist
Pesticide & Fertilizer Management Division
Minnesota Department of Agriculture (MDA), 625 Robert Street N, St. Paul, MN 55155-2538, email@example.com