Hayford Bridge Road Site
The Hayford Bridge Road Superfund Site has been divided into three operable units by the United States Environmental Protection Agency (USEPA) and the Missouri Department of Natural Resources (Missouri DNR) :
• Operable Unit No. 1 – includes the soil and shallow groundwater contamination on the former Findett property
• Operable Unit No. 2 – includes the soil contamination on the former Cadmus property
• Operable Unit No. 3 – includes contaminated groundwater that has moved north and northeast of the Findett and Cadmus properties
1. Operable Unit No. 1
In 1992, a groundwater treatment system was installed on the Findett property to remove hazardous chemicals present in groundwater. The system has operated nearly continuously since it was installed. Additionally, a work plan for the treatment of contaminated soils was submitted in 1994, and within two years of construction of the biotreatment system in August 1999, the process had achieved an 80% reduction in hazardous chemical concentrations in soil. In 2003, the shallowest 5 -feet of soil beneath the Findett property was excavated and transported to a landfill for disposal following approval by the USEPA and the Missouri DNR.
2. Operable Unit No. 2
In 2001, nearly 2,000 tons of soil were removed from beneath the Cadmus property. In 2003, seventy-one additional truckloads of contaminated soil were removed from the Cadmus property. After which 18 -inches of clean soil was placed within the excavated areas on the property.
3. Operable Unit No. 3
An investigation was performed by Findett, Cadmus, and other responsible parties under the direction of the USEPA and Missouri DNR between 2002 and 2005 to define the extent of hazardous chemicals and consider options for cleaning up the groundwater in the Elm Point Wellfield. Hazardous chemicals in groundwater had moved beyond the limits of the Findett and Cadmus properties despite the nearly continuous operation of the groundwater treatment system since 1992. A Record of Decision was issued by the USEPA in September 2005, and a Consent Decree was agreed to by the USEPA and the responsible parties in 2007 for removing the remaining hazardous chemicals from groundwater that were released by Findett and Cadmus.
Four hazardous chemicals were identified in groundwater including:
• Vinyl chloride
The USEPA and Missouri DNR determined that no additional treatment was necessary to remove these four hazardous chemicals from groundwater. Findett, Cadmus, and the other parties responsible for the contamination simply needed to track the concentrations over time until the concentrations reached levels considered safe by the USEPA. These levels are called the Maximum Contaminant Levels or MCLs. Findett and Cadmus were also required to complete the following activities:
• Establishing practices that would prevent exposing workers from contaminated soil that remains on the former Findett and Cadmus properties, which was completed in May 2019.
• Establishing restrictions that prevent anyone from installing a drinking water well on the Findett or Cadmus properties, which was completed in May 2019.
• Upgrading the City of St. Charles drinking water treatment plant. While a design report was drafted in February 2011, these upgrades were never built by Findett, Cadmus, or the other responsible parties.
• Preparing contingency plans in the event that hazardous chemicals were found to be increasing or threatening the City of St. Charles drinking water wells. These plans were never prepared.