Background
Work at this site was performed under an AOC between the client and USEPA Region III. PCBs were detected in soil, steel, sediment, concrete, and paint in multiple low and high occupancy locations throughout the facility. Therefore, AGES staff developed a remediation plan, negotiated with the USEPA, established the scope of work and oversaw the implementation of the project.
Remediation Project Work
Paint Removal and Encapsulation
Some areas on the operations level had grossly peeling paint with low PCB concentrations. All damaged paint was removed according to the client's specification, either by manual scraping, shot-blasting, brush-grinding or similar method. Following surface preparation, the areas were covered with a single coat of paint.
Additionally, some components were coated with PCB-impacted paint at levels that exceeded site-specific worker exposure levels. All damaged paint was removed from surfaces by manual scraping, shot-blasting, brush-grinding, or similar methods. After preparation, the surfaces were painted with two (2) layers of contrasting-colored paint, in general accordance with the continued use authorization under the regulations.
Building Demolition (Decontamination and Decommissioning)
Based on the extent of PCB impacts throughout one of the buildings, the client determined that demolition was preferable to extensive remedial actions. So, impacted equipment and materials were removed from the building and properly disposed of in accordance with 40 CFR 761. Then, asbestos windows were removed from the building, carefully wrapped in plastic and placed into asbestos roll off box. PCB-impacted roof panels and siding were then carefully removed to keep loose or failing paint intact. Finally, the remaining aboveground components and concrete floor slab were demolished and placed into roll off boxes. All building components were disposed of properly off-site.
Basement Concrete Remediation #1
Within the low-occupancy basement of another building, PCBs were detected in a limited area in concrete. AGES staff oversaw chemical cleaning treatments to extract the PCBs. After the application, the chemical extraction was vacuumed into 55-gallon drums and the concrete was re-tested. Based on both immunoassay kit testing and laboratory results, PCB concentrations were less than 25 mg/kg and no further action was required.
Basement Concrete Remediation #2
Within the low-occupancy basement a separate building, PCBs were detected in concrete. AGES staff oversaw scarification of the floor with a dustless scabbling system. Based on screening with immunoassay kits, PCB concentrations still exceeded the specified action level. Based on these results, a portion of the floor was removed with a jackhammer. Upon removal of the floor, the basement area was backfilled with gravel and covered with a concrete floor. The basement floor was then painted with two (2) contrasting colors in accordance with the regulations.
Roof Replacement
Based on the extent of PCB impacts and age, the client decided to remove and replace a building roof rather than conduct remedial actions. Ceiling tiles and rubber roof were removed from the building and all grossly peeling paint was scraped off by hand. Then, the structure was painted with a single coat and new ceiling tiles and rubber roof were installed.
Steel Drain lines Cleaning
PCBs were detected in wipe samples collected from a network consisting of hundreds of feet of buried steel drainlines at concentrations less than the low occupancy action level. However, because the drainlines discharged to a nearby river, the client opted for clean-up to the most stringent high occupancy standard. AGES staff oversaw cleaning of the drainlines via jet-washing, detergent cleaning and chemical cleaning. After multiple rounds of cleaning, wipe samples indicated that PCBs had been effectively removed from the lines.
Soil Excavation
AGES staff oversaw the excavation of over 150 cubic yards of PCB-affected soil from three (3) areas of the site. Laboratory samples were collected to confirm that applicable action levels had been achieved. In the field, AGES staff used immunoassay test kits to screen samples in the field resulting in rapid completion of field work with no re-mobilizations.
Temporary Water Treatment System
AGES developed a temporary system to re-rout and treat storm water prior to discharge into a nearby creek. The system included filters to remove sediment and multiple liquid-phase carbon units to strip any PCBs that may be present in the water. The system was serviced weekly and water samples were routinely collected and analyzed for PCBs to ensure that all components were operational and functioning as intended.
Special Project Features
1.) AGES used field immunoassay test kits to guide field work in both soil and concrete, which decreased the number of lab samples and eliminated costly re-mobilizations.
2.) By applying site-specific data, use-specific action levels were used; this limited the scope of remedial work that was required.
3.) In combination with the testing and data applications, AGES negotiated extensively with the USEPA and ensured that the project met regulatory requirements in a cost-effective manner.
