The HoltraChem Site (also known as Acme Alkali) is comprised of approximately 24 acres and is located at 636 John L. Riegel Road in Riegelwood, Columbus County, North Carolina. It is surrounded on three sides by International Paper (IP), which is comprised of approximately 1,500 acres. Both HoltraChem and IP border the Cape Fear River. The surrounding area is a mixture of industrial, residential and commercial uses.
The area subject to this removal action includes neighboring IP’s North Bay treatment pond, also known as Cell #2. IP formerly accepted process water generated during chlorine production from the Holtra Chem facility. HoltraChem operated as a chlor-alkali facility using the mercury cell process from 1963 to 1999, when facility operations ceased. HoltraChem was originally constructed to provide chlorine gas, caustic soda, and bleach to the IP facility. Process water from the former HoltraChem facility was reportedly discharged to the northwest corner of Cell #2 via a 16-inch diameter, corrugated galvanized steel pipe from approximately 1963 to the late 1970s or early 1980s.
A time-critical removal action was conducted at the HoltraChem Site during 2003 – 2004, during which containerized hazardous waste and the former cell building were removed. In 2004, an Engineering Evaluation / Cost Analysis (EE/CA) investigation began at the Site. During the EE/CA, the primary contaminants of concern were identified as mercury and PCB Aroclor 1268. Sampling conducted by IP identified PCB Aroclor 1268 at concentrations up to 5,100 mg/kg in Cell #2. PCB contamination extends to a depth of approximately 12 feet below the ground surface. PCB contamination has been found in the adjacent Cape Fear River sediments. IP needs to utilize Cell #2 for the expansion of their landfill sooner than the EE/CA will be completed. Therefore, a Time-Critical Removal Action is being taken to excavate the contaminated Wastewater Treatment Solids (WWTS) from Cell #2 and place the WWTS with concentrations exceeding 50 mg/kg in temporary storage on the HoltraChem Site until the final cleanup plan is selected for HoltraChem. The estimated volume of this material is 6,500 cubic yards. The cleanup goal for this removal action is 11 mg/kg based on the Human Health Risk Assessment for the Holtra Chem Site. WWTS with concentrations between 11 mg/kg and 50 mg/kg will also be excavated, but will be placed in IP’s landfill Cell #1. The estimated volume WWTS with PCB concentrations between 1 mg/kg and 49 mg/kg is 93,500 cubic yards.
The Enforcement Action Memorandum for this time-critical removal action was signed on May 13, 2008. The Effective Date of the Administrative Order on Consent for this removal action was May 20, 2008.
The PRPs’ contractors, CH2M Hill and Shamrock Environmental, mobilized to the Site on Monday, May 19, 2008. Activities conducted on May 19th and May 20th included mobilization, safety training, equipment and materials delivery, site and office set-up, collection of water samples, surveying, and set-up of the water treatment system to be used in dewatering Cell #2.
On Wednesday, May 21, 2008, construction began on the stockpile containment system for the temporary storage of PCB-contaminated WWTS. The existing old cell building pad, which will be the location of the new stockpile, was inspected and large debris (i.e. broken concrete, rebar, metal, construction debris, trash, etc.) was removed. Road plates were placed over the drainage depression in the center of the old cell building pad which flows to the cell pit. The plates were then covered with geofabric. Construction began on the stockpile berm walls (northwest and southwest walls). Stockpile berm soils consisted of soil obtained from Grid M-10 (<50 mg/kg PCB) in IP’s Cell #2.
On Thursday, May 22, 2008, construction of the berm walls continued, as well as placement of clean soil on the base of the old cell building pad to a thickness of at least four inches. Dust control measures were implemented during construction activities. The stockpile liner was delivered, however, the product delivered was not the product ordered. The Work Plan called for 40-mil high density polyethelene (HDPE) liner. The product delivered was geofabric. The supplier does not have any 40-mil HDPE available but did have 60-mil HDPE that could be delivered the next day. CH2M Hill discussed the issue with EPA and NCDENR. Both agencies approved the change to 60-mil HDPE for the bottom liner since it is more durable than the 40-mil liner and can be obtained quickly.
Analytical Data was received on the fly ash and standing water samples that were collected on May 19, 2008. TCLP results of the fly ash indicated low levels of barium, cadmium and chromium, all below toxicity characteristics limits. Fly ash will be used to stabilize the WWTS prior to transport, if needed. Sample results from standing water currently located in Cell #2 indicated concentrations of 0.15 J µg/L and 0.13 J µg/L of Aroclor 1268. The Work Plan requires that water be treated to below 3 µg/L prior to discharge to IP’s water treatment system.
On Friday, May 23, 2008, CH2M Hill, Shamrock Environmental, and EFI continued construction activities. The new stockpile berm walls were completed. Approximately 546 cubic yards of soil from Grid M-10 of Cell #2 was used in the construction of the new stockpile berm walls and as covering for the old cell building pad prior to liner placement. EFI personnel lay out and began seaming the 60-mil liner sections for the stockpile.
There were no weather delays during this reporting period week. The days were sunny and warm with temperature ranges from 61oF to 85oF. David Mattison of North Carolina Department of Environment and Natural Resources (NCDENR) was at the Site this week providing oversight. No work was conducted at the Site Saturday through Monday, May 24-26, 2008 for observance of Memorial Day.
The PRPs’ contractors will return to the Site on Tuesday, May 27, 2008, to continue removal activities. EPA RPM Samantha Urquhart-Foster and Honeywell’s Project Manager, Prashant Gupta, will be on-site. Activities planned for May 27-31, 2008 include completion of seaming of the liner, construction of decontamination areas, and begin excavation of Cell #2.
Removal activities are planned through July 15, 2008, with demobilization scheduled for the first week of August 2008.
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