Significant Project Features
- Self-performed excavation, characterization, and T&D of >49K CY of soil impacted by hazardous contaminants, including VOCs, SVOCs, PCBs, pesticides, asbestos, and heavy metals
- Installation of 488 LF of steel sheeting to protect existing structures
- Demolition and disposal of 13 buildings (totaling 63K SF) impacted by asbestos and lead contaminants
- Managed and coordinated multiple hazardous and non-hazardous wastestreams, including >65K tons of non-hazardous soil and debris
- Designed, constructed, operated, and maintained a temporary on-site 150-GPM WWTP (treated and discharged >2.5M gallons of contaminated water)
- Completed >62K safe workhours without a lost-time incident
- Earned “VERY GOOD” project evaluation ratings on Interim CPARS
History & Location Details
Located in a heavily industrialized section of South Kearney, New Jersey, the 15-acre Syncon Resins Superfund Site facility formerly produced alkyd resin carriers for pigments, paints, and varnishes. The site consisted of reactor buildings, high-volume storage tanks, two unlined lagoons, USTs, and piping infrastructure. Waste disposal operations contaminated the site’s groundwater, soil, and buildings.
Prior to commencing remediation activities, Sevenson obtained permits; documented the site using photographs and video footage; staged, calibrated, and maintained four perimeter air monitoring stations; initiated a third-party land survey to mark out existing utilities/site infrastructure; and installed sediment and erosion controls, which included silt fencing and hay bales. Additionally, field crews set up temporary facilities and mobilized heavy equipment, including PC300 and PC400 excavators (with grapple and hoe-ram attachments), off-road dump trucks, front-end loaders, bulldozers, and a water truck. Field crews then performed clearing and grubbing to gain access to buildings flagged for demolition and designated excavation areas. All cleared organic and wood debris were chipped and disposed of on site.
Site preparation also included the construction of the stockpile containment area, which was constructed of quarry dust, 40-mil HDPE liner, and geotextile fabric that encompassed a 10K-SF area. Sevenson also installed concrete bin blocks along the stockpile containment area to hold excavated contaminated material.
Sheet Pile Installation
For sheet pile installation, Sevenson mobilized a PC300 excavator (equipped with a Robo-Vibe attachment) and a front-end loader. Crews installed 488 LF of sheeting to 28.5-ft. BGS. At the outset of the project, the original design required installing 350 LF of sheeting; however, during test pit excavation and waste characterization sampling, Sevenson anticipated that deep excavation within one area could progress into the shallow excavation of another. Following discussions with the USACE and the project team, Sevenson installed an additional 138 LF of sheeting to protect an existing slurry wall in case deep excavation expanded in that direction.
Before building demolition, field crews performed required pest and rodent abatement at each building. Additionally, Sevenson managed a specialty licensed subcontractor to inspect and abate asbestos- and lead-impacted materials within the buildings. For all buildings that were deemed unsafe to enter, crews performed demolition using an approved “wet” method to mitigate dust migration.
Following abatement activities, Sevenson demolished 13 buildings, totaling over 1,900 tons of debris. Demolition work also included moving, segregating, and stockpiling all contaminated concrete building slabs, aboveground utilities, aboveground storage tanks, railroad spurs, tank holders, and subsurface components. Concrete slabs/foundations and subsurface components were demolished using a PC300 excavator equipped with a hoe-ram attachment. Operators sized all concrete in accordance with disposal facility WAC. Sevenson coordinated the segregation and recycling of all steel material, which totaled over 590 tons of concrete debris and over 718 tons of scrap metal.
After demolition and prior to excavation activities, Sevenson conducted pre-excavation sampling under the concrete slabs of six buildings. Samples were collected from 24 soil boring locations. Sample analysis verified no existing contamination under the slabs. Sevenson excavated 49K CY of contaminated soil. Excavation depths ranged from 2-ft. to 12-ft. BGS. PC300 excavators loaded material into off-road haulers which then transferred material to the stockpile containment area. During primary excavation, field crews encountered considerably high volumes of dense oversized debris, such as concrete, wood, and steel cables. Sevenson removed, sized, segregated, and stockpiled all debris at the stockpile containment area. Concrete debris was sized using a hoe-ram attachment.
Field crews performed waste characterization on each 500-CY pile of material. All samples were collected in situ using test pit excavations. Based on analytical results, secondary excavations were performed when side walls and/or floor samples exceeded the cleanup criteria. Following additional confirmatory sampling that verified cleanup criteria were achieved, Sevenson began backfilling. In order to minimize open excavations, field crews sequenced work so that excavated areas were backfilled individually before an entire area was verified clean.
During excavation, Sevenson implemented a combination of Rusmar® foam and BioSolv solutions to mitigate odor and VOCs. The foam was used to cover open excavations, stockpiles, excavator buckets, and triaxles. BioSolv was used as a spray application to mitigate VOC emissions. Stockpiles and open excavations’ side walls/floors were also covered with poly sheeting. Excavation crews also handled water infiltration by using dewatering pumps and hoses. Water was transferred to the on-site 150-GPM WWTP, which treated over 2.5M gallons.
Waste Segregation and T&D
Sevenson managed multiple high-volume hazardous and non-hazardous wastestreams. Soil was segregated according to its characterization results. Soil classified as non-hazardous (Subtitle D) was stockpiled in a designated area and loaded for off-site T&D as it was excavated. Soils that were characterized as TSCA or RCRA were staged before off-site disposal. Crews coordinated all T&D activities, including manifest preparation and weight ticket documentation, for trucks transporting material for off-site disposal. Wastestreams prepared and sent off site for disposal include:
- Demolition debris: 93 truckloads, >1,900 tons
- Concrete debris (recycled): 26 truckloads, >591 tons
- Scrap metal (recycled): 57 truckloads, >718 tons
- Subtitle D soil material: 2,146 truckloads, >55,975 tons
- Construction & demolition: 300 truckloads, >5,759 tons
- Timber/wood debris: 99 tons
- Non-friable asbestos material: 177 truckloads, >3,400 tons
- RCRA lead material: 62 truckloads, >1,680 tons
- RCRA arsenic and cadmium material: 37 truckloads, >800 tons
- RCRA thermal treatment (low flash point and chromium material): 58 truckloads, >1,200 tons
- TSCA PCB material: 530 truckloads, >11,850 tons
- Fluorescent lighting (possibly contaminated with PCBs): 25 tons
- High-VOC drum residuals: 66 tons
Demobilization and Site Restoration
Demobilization involved demolishing and removing the temporary stockpile and WWTP areas. Sevenson also removed all temporary facilities and decontaminated all heavy construction equipment using power washers.
Backfill operations involved importing and placing over 52,700 CY of backfill material. Sevenson managed a NJ-licensed surveyor who verified fill depths of sub/final grades and collected final data for As-Built drawings. Field crews also reinstalled an extraction well and a portion of a collection trench that was removed during excavation activities. Additionally, Sevenson oversaw a subcontractor that installed 11 new monitoring wells across the site. Following restoration, Sevenson collected post-construction videos and photographs.
Health & Safety oversight was critical for this project due to the proximity of excavation operations to nearby office buildings and a municipal wastewater treatment plant. Of particular concern was monitoring and abating noxious odors and VOC emissions to ensure their migration did not impact the daily activities of these businesses and on-site personnel. H&S officers oversaw and tracked data provided by air monitoring stations to prevent potential perimeter action level exceedances. Sevenson’s air monitoring program monitored various odors and particulates, including dust, VOCs, benzene, lead, PCBs, BTEX, naphthalene, MEK, acetone, ethyl acetate, PAHs, and respirable silica dust. On-site personnel completed >62K safe workhours without a lost-time incident.