2.1.1 Narrative

Due to the presence of elevated levels of dioxin in soil at the Site, the EPA is conducting a time-critical removal action to reduce potential exposure to nearby human populations, animals and the food chain. Removal criteria is set by the site's Action Memorandum. Soils exceeding 820 parts per trillion (ppt) from 0 to12 inches below ground surface (bgs) will be removed. At depths equal to or greater than 12 inches bgs, removal of soils will continue until a residual dioxin concentration of less than three times the site-specific cleanup goal, or 2,460 ppt, is reached.

Samples collected at this Site are being submitted to a laboratory in North Carolina for dioxin analysis. Turn-around between the time a sample is received by the laboratory and the time results are made available is 72 hours.

Dioxin-contaminated waste generated at this site is being treated as F027 dioxin-bearing waste. The Universal Treatment Standard (UTS) for F027 dioxin-bearing waste is 1 ppb (40 CFR § 268.48). The alternative Land Disposal Restrictions (LDR) treatment standard (40 CFR § 268.49) states that treatment to achieve constituent concentrations less than ten times the UTS is not required. Dioxin-contaminated waste generated during the removal, up to concentrations of 10 ppb 2,3,7,8-TCDD, will be transported to an off-site RCRA-permitted hazardous waste facility located in Waynoka, Oklahoma, for proper management.

Dioxin-contaminated materials with an average concentration greater than the alternative LDR treatment standard for contaminated soil will be managed by a facility capable of meeting the UTS for F027 dioxin-bearing waste. 

Contaminated soil is being direct loaded into the red 25-cubic-yard roll-off boxes. Boxes are lined prior to filling and covered immediately after being loaded.

2.1.2 Response Actions to Date

August 8, 2014 through March 24, 2015

The last roll-off waste boxes of dioxin contaminated soil excavated during this action were shipped off-site on September 19, 2014.  

Restoration activities were complete at the site on 10/31/2014.  Restoration activities included removal of the access road constructed at the beginning of the project to access the work area.

Environmental covenants establishing land use restrictions for the extreme northeast corner of the property and encompassing the work zone were executed in March 2015 and will be on file with the St. Louis County Recorder of Deeds.  The covenants establish land use and soil restrictions for portions of the site with surface soil dioxin TEQ levels below the removal action level of 820 ppt.

Waste Box Summary Totals

Boxes up to concentrations of 10 ppb 2,3,7,8-TCDD that have been transported to the off-site RCRA-permitted hazardous waste facility located in Waynoka, Oklahoma, for proper management: 84 (1,278 tons)

Boxes exceeding concentrations of 10 ppb 2,3,7,8-TCDD that have been transported to the off-site hazardous waste facility located in Saint-Ambroise, Quebec, for treatment and disposal: 17 (267 tons)

Transportation and Disposal. Total dioxin contaminated soil shipped offsite: 1,545 tons in 101 roll-off boxes.

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)

Enforcement options are being evaluated. 

2.1.4 Progress Metrics

2.2.1.2 Next Steps

No additional steps planned. 

2.2.2 Issues

No issues to report during this operational period.