Extensive remediation of superfund site - case study
The 80 acre site, formerly a minerals processing facility, was operated primarily to recover lithium and other rare-earth minerals from ores. Raw ores were imported to the site for processing. During one phase of its operations, the facility also processed uranium ores for the government. The site was listed as by the U.S. Environmental Protection Agency (EPA) as a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) site, commonly referred as Superfund.
Sustainable Resources Group, Inc. (SRG) provided various services for the remediation of this Superfund site. This project was unique in that all of the work through July 2008 was performed 'at risk' prior to the lodging of the Consent Decree and well over 80% of the field work had been completed before the Consent Decree was entered by the Court. SRG and the Engineer of Record maintained at least weekly dialogs with EPA and monthly dialogs with the local communities to expedite the remedial effort.
The completed work included the following:
- Program Management - SRG assisted in the selections of the Engineer of Record and the In-Situ Stabilization contractor, provided regulatory interface for all site activities, and managed the project costs & schedule to implement the remedy selected in the Record of Decision (ROD).
- Demolition – SRG demolished and disposed of over 30 processing buildings and associated concrete foundations, steel, and site features.
- In-situ Stabilization – SRG provided supervision, equipment, labor, and other support services for implementation of the ISS remedy.
- Excavation – SRG performed the excavation of chemically impacted soils, temporarily staged them on site pending completion of the ISS work, and then placed them in the quarries above the stabilized tailings.
- Sampling and Analysis – SRG developed the Sampling and Analysis Plan, performed the confirmatory sampling, subcontracted the analysis to an EPA approved lab, and maintained the database of sampling locations and laboratory results for use in preparation and submittal of cleaned area result summaries to EPA.
- Remediation of Naturally Occurring Radioactive Materials (NORM) – SRG developed the NORM investigation and remediation work plans, then implemented those plans to identify and remove over 13,500 tons of NORM impacted soils.
- Capping – Upon completion of consolidation of the chemically impacted soils into the quarries, SRG constructed a multi-layered, geo-synthetic cap.
As Program Manager, SRG represented the owner for the performance of the In-Situ Stabilization remedy. The on-site quarry was used for tailings disposal during the plant's operations. The ROD required that tailings which existed below the normal water table be stabilized to prevent migration of the mineral contaminants. As the remedial contractor SRG provided equipment and assistance for the stabilization of over 110,000 cubic yards of tailings.
SRG performed the delineation and excavation of contaminated soils. Areas of concern identified during the Remedial Investigation (RI) wereFED_cap_cover excavated, sampled, and expanded based upon post excavation sampling so that many of the ore storage areas and processing building footprints expanded from their original size or shape identified in the RI. A complication of the cleanup process was that the ROD clean up requirement was based upon direct contact and Human Health Risk Assessments derived from assumed values. SRG assisted in the preparation of EPA's Explanation of Significant Differences (ESD) to increase the allowable levels of some contaminants based upon site specific background conditions naturally occurring in the area.
Radiologically impacted soils resulted from uranium processing conducted during the 1940's. This Naturally Occurring Radioactive Material (NORM) was delineated and removed by SRG to a permitted off-site disposal facility. All work plans, including the Radiation Safety Plan and Final Status Survey Plans were developed by SRG with subcontracted health physics technicians to assist in the performance of this task.
During 2010, SRG managed cap design changes for the owner to permit future construction of a solar panel electric generating system on the site. The design was developed and constructed by SRG in close cooperation with the EOR and USEPA so that the project could be completed by the close of USEPA's FY 2010 in September 2010.