(The photo associated with this POLREP is of excavation activities occurring in Cell #2.)
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 was 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 was 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.
David Mattison, NCDENR, provided oversight of removal activities during this reporting period (October 6 - 12, 2008), with RPM Samantha Urquhart-Foster coordinating from the office.
* Note: Cell #2 was divided into 100'x100' and 50'x50' grids during the investigation phase. Grids are labeled with a letter and a number. Grid locations can be found in a Figure in the Action Memo.
Activities conducted by the PRPs' contractors during this reporting period included:
Excavation Activities:
* Continued excavation/transportation of material with PCB Aroclor 1268 concentrations greater than 50 mg/kg. On October 10, 2008, approximately 120 cubic yards of soil was transported from IP Cell #2 to Engineered Stockpile (ES) #2. This material orginated from Grid G-6NE. This is expected to be the last amount of material with concentrations exceeding 50 mg/kg, however, several confirmation sample results are still pending.
* Continued excavation/transportation of material with PCB Aroclor 1268 concentrations less than 50 mg/kg. During October 6-10, 2008, approximately 3,540 cubic yards of soil was transported from IP Cell #2 to IP's landfill. This material orginated from Grids G-4, G-5, H-4, H-5, I-3, I-4, I-5, I-6NE, I-6SW, J-4, M-4, M-5, O-14, S-6, S-8, and S-10.
[Note: ES #1 is at capacity with approximately 8,000 cubic yards of material. The top and bottom liners have been seamed together. As of the end of this reporting period, ES #2 is estimated to contain 11,328 cubic yards.]
Dewatering Activities:
* Rain fell on the Site on two days during this reporting period, with amounts ranging from 0.15 to 1.55 inches per day.
* During October 7-11, 2008 approximately 126,400 gallons of water from Cell #2 was pumped, treated, and discharged to IP.
* The total volume of water treated since treatment operations began on June 18, 2008 is approximately 4,087,000 gallons.
Sampling Activities:
* Collected confirmation, water treatment, and wipe samples.
Analytical Data received during the reporting period:
* Confirmation sample data from grids G-6, G-8 and I-8 were received during this reporting period. All results were below the cleanup goal of 11 mg/kg for Aroclor 1268 with the following exceptions: the base of Grid G-6 NE and SE quadrants, and Grid I-8 NW quadrant (230 mg/kg, 31 mg/kg, and 18 mg/kg respectively). The PRPs are attempting to achieve remediation levels of less than 1 mg/kg. The bases of grids G-8SW, I-8SW, and I-8NE had concentrations between 2.3 and 3.2 mg/kg.
* Water treatment data from samples collected on 10/2 were 1.1 ug/L of Aroclor 1268 for the influent and undetected with a maximum detection limit of 0.63 ug/L for the effluent. (The treatment goal is <3 ug/L.)
David Mattison of NCDENR will provide oversight during the next reporting period, October 13-19, 2008. Activities planned for the next reporting period include:
* Continue water treatment system operations.
* Collect water treatment system samples.
* Continue excavation/transportation of <50 mg/kg material to IP's landfill.
* Collect confirmation samples from base and sidewalls of excavated grids.
* Scrape additional material from the base/sidewalls of grids where analytical results indicated exceedance of cleanup goals.
* Overexcavate the pipe trench.
* Begin installation of the top liner on ES#2.
* Investigate other decontamination methods for heavy equipment.
The schedule for the completion of the removal activities has been extended from October 23rd to November 6, 2008, due to confirmation sample results indicating material above the cleanup goal remaining in the bottom of some of the grids. The demobilization date is highly dependent upon sample results from bottom scrapes. Confirmation results from several grids are pending.
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