|Evaluation of Soil Amendment Technologies at the Crooksville/Roseville Pottery Area of Concern, STAR Organics Soil Rescue, Innovative Technology Evaluation Report |
SITE Technology Capsule (540/R-09/501a)
Star Organics, LLC, of Dallas, Texas, has developed Soil Rescue to treat soil contaminated with metals. Star Organics claims that Soil Rescue forms metal complexes that immobilize toxic metals, thereby reducing the risk to human health and the environment.
The Superfund Innovative Technology Evaluation Program evaluated an in situ application of the technology during a demonstration at two lead contamination sites in Roseville, Ohio, in September 1998. For the demonstration, Soil Rescue was applied to ten experimental units at a trailer park and one experimental unit at an inactive pottery factory.
The primary objective was to evaluate whether Soil Rescue could treat soil contaminated with lead to meet the Resource Conservation and Recovery Act (RCRA) and Hazardous and Solid Waste Amendments alternative universal treatment standards (UTS) for land disposal of soils contaminated with lead.
The alternative UTS for soil contaminated with lead is determined from the results of the toxicity characteristic leaching procedure (TCLP). The alternative UTS is met if the concentration of lead in the TCLP extract is no higher than one of the following:
Soils contaminated with TCLP lead concentrations below the alternative UTS meet the RCRA land disposal restrictions and are eligible for disposal in a land-based RCRA hazardous waste disposal unit. The alternative UTS is defined further under Title 40 of the Code of Federal Regulations, Chapter 1, Part 268.49. To meet that objective, soil samples were collected before and after the application of Soil Rescue. The untreated and treated soil samples were analyzed for TCLP lead concentrations to evaluate whether the technology met the primary objective.
Analysis of the data demonstrated Soil Rescue reduced the mean TCLP lead concentration at the inactive pottery factory from 403 mg/L to 3.3 mg/L, a reduction of more than 99 percent. Therefore, the treated soil meets the alternative UTS for soil at the inactive pottery factory.
Data from the trailer park were not analyzed against the primary objective because TCLP lead concentrations in all treated and untreated soil samples from this location were either at or slightly higher than the detection limit of 0.05 mg/L.
The second objective was to evaluate whether Soil Rescue could decrease the soil lead bioaccessibility by 25 percent or more, as defined by the Solubility Bioaccessibility Research Consortium's Simplified In Vitro Test Method (SVIM) for Determining Soil Lead and Arsenic Bioaccessibility. However, the EPA Lead Sites Workgroup and the Technical Review Workgroup for lead do not endorse an in vitro test for determining soil lead bioaccessibility.
To meet the second objective, soil samples were collected before and after the application of Soil Rescue. The soil samples were analyzed for soil lead bioaccessibility to evaluate whether the technology met the second objective.
Analysis of the data demonstrates that Soil Rescue reduced the soil lead bioaccessibility by approximately 2.9 percent, which is less than the project goal of at least a 25 percent reduction. However, it was recognized early on that meeting this goal would be difficult because the SIVM test procedure used in the demonstration involves a highly acidic sample digestion process (which may be revised in the future) because it may be exceeding the acid concentrations that would be expected in a human stomach.