Site background information can be found on Pollution Report #1 – Initial POLREP.
From 1956 until approximately 1976, Industrial Metal Alloy Company, operated a solder manufacturing company at the Site. Taracorp, Inc., and its predecessor corporations leased the Site to operate a solder manufacturing facility at the Site from 1976 through 1993. NK Holdings, LLC was formed in 2005 and is the corporate successor to Taracorp, Inc.
Slag with high levels of lead has been found in several locations around the IMACO property. Lead contaminated dust was also believed to have escaped through ventilation from the facility while it was in operation. Analytical results indicated that contamination occurs in the surface and subsurface soils above the removal action levels (RAL) for lead and arsenic of 400 ppm and 40 ppm, respectively. The maximum lead concentration detected in surface soils was 113,821 ppm, and the maximum arsenic concentration in surface soils was 430 ppm.
NK Holdings signed a consent agreement with EPA on September 20, 2006 to perform the removal work at the Site. The removal will involve excavation, treatment, and disposal of contaminated soils from the IMACO lot, the Colter Electric property located East of the lot, and three nearby residential yards. EPA will oversee the work done by NK Holdings over the course of this removal action.
On October 24, 2007, a conference call was conducted between EPA, HEPACO, and Brown & Caldwell to discuss sampling results and other Site-related issues prior to excavation. It was determined from the sampling results that no excavation would be necessary in the following grid locations: A6, A7, A8, B9, D7, D8, K21, L6, L19, L20, L21, M6, N2, N3, O3, O4, O6, O7, O8, O9, P2, P3, P4, P5, P6, and P7. Grids A9 and D6 had been cleared for no excavation due to sample results obtained by Brown & Caldwell (307ppm and 393ppm respectively), but EPA samples taken October 18 had shown that these grids exceeded the screening level (1040ppm and 470ppm respectively) and as a result these grids will be excavated. Grid O5 had been cleared for no excavation by EPA’s sampling results (358ppm), but results obtained by Brown & Caldwell in this location exceeded the screening level (523ppm) and as a result the grid will be excavated.
The conference call on October 24 also addressed the following issues:
- Potential recyclers will be immediately sought to address the Kettle Bottoms
- HEPACO and/or Brown & Caldwell will produce a written plan to address Slag Pieces during excavation
- Slag Pieces will be hand-picked when possible and recycled with Kettle Bottoms
- HEPACO and/or Brown & Caldwell will obtain a letter from NK Holdings to sign disposal manifests on their behalf
On October 29, HEPACO remobilized to the site to begin excavation. Triple Super-Phosphate fertilizer was added to grid cells: A9, A10, B10, B6, D6, C6, C7, and C8 prior to excavation at a volume of approximately 3% by weight. Soil is being excavated at 6” intervals, after which a sample is taken and analyzed with XRF. If the sample meets cleanup criteria, it is stored to be sent later for laboratory analysis. If the sample exceeds cleanup criteria, another 6” layer is removed and a new sample is taken. Per the language in the AOC, excavation will occur up to a depth of 24”.
On October 31, EPA met with HEPACO and Brown & Caldwell on-site to discuss sampling protocol and proper documentation to reflect activities at the Site. The following changes will be documented for future sampling:
- CONFIRMATION SAMPLES: a ¼ inch screen will be used; if slag is visually observed in the sample, another 6” will be excavated from the grid and a new sample will be collected.
- WASTE PILE SAMPLES: a ¼ inch screen will be used; samples will be crushed appropriately to fit through the ¼ inch screen prior to analysis.
CLEARED GRIDS:
- A9 at 6 inches (October 30)
- D6 at 6 inches (October 30)
- B6 at 24 inches (October 31)
- C6 at 6 inches (October 31)
- C7 at 6 inches (October 31)
- A10 at 12 inches (October 31)
- B10 at 12 inches (October 31)
- B8 at 6 inches (November 1)
- C8 at 6 inches (November 1)
- C9 at 6 inches (November 1)
- C10 at 6 inches (November 1)
- D10 at 6 inches (November 2)
- D9 at 24 inches (November 2)
- F9 at 18 inches (November 2)
- Sampling to determine the aerial and vertical extent of contamination on-site and on adjacent properties (COMPLETE)
- All soils and sediments on-site and on adjacent properties which are contaminated above RALs shall be excavated (ONGOING)
- All waste streams shall be disposed of by appropriate measures as determined by the disposal profile
- Restore areas which are disturbed by the removal action to their pre-removal state to the maximum extent practicable
Excavation will continue the week of November 5 with grid cells: G9, H9, I9, J9, K9, L9, M9, N9, O9, N1, N4, K6, L5, M5, N5, N6, N7, and O5.
An access agreement will need to be obtained for the property at 15 East Monmouth Street. The boundary for this property extends across to the north side of the creek. Although no excavation will take place at this location, it will be necessary to move equipment near or across the property, and remove vegetative debris from within the property.
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