Metal Bank Superfund Site

Philadelphia, Pennsylvania
Date of Execution: July 2009

Significant Project Features:

Installation of 700 lf temporary steel sheet piling to control turbidity.
Mechanical dredging of 4,000 cy PCB sediments utilizing an environmental clam bucket and crawler crane.
Stabilization of dredged sediments and transfer to stockpile area for characterization and off site T+D.
Installation of 600 lf of LNALP collection trench. TSCA material generated during trench installation transferred to stockpile for characterization and off site T+D.
Placement of 60,000 sf of Triton marine mattresses with a crane mounted on a barge and diver assistance.
Continuous turbidity monitoring with four (4) real time monitors.

History and Location of Project
The Metal Bank site occupies approximately ten acres along the Delaware River in an industrial section of northeast Philadelphia. From 1968 to 1972, Metal Bank of America, Inc. drained oil from used transformers to reclaim copper parts. Metal Bank's recycling operations released oil in various locations on the property. The company performed a limited cleanup to prevent further releases. However, oil continued to seep from the Site.

PCBs and various other hazardous substances have been detected in the surface and subsurface soils onsite and in Delaware River sediment. There is also the presence of oil on the surface of the groundwater, in subsurface soils, and river and mudflat sediments. The PCB-contaminated oil has moved into the Delaware River as a result of groundwater and tidal wave movements underneath the Site. PCB-contaminated sediments have been detected along the shoreline immediately adjacent to the property line.

Under the terms and conditions of a Consent Decree, a remedial design was submitted to EPA for approval. The final design was approved on February 28, 2008. Remediation began in July 2008 and ceased in January 2009 for the winter. Cleanup activities resumed in July 2009 and remediation was completed in December 2009.

Description of Work

After mobilization to the site a survey was performed to document existing site conditions as well as establish control points for site layout. Access roads, work zones and erosion control measures were installed. A 100 GPM temporary wastewater plant was erected to treat all water encountered during remediation. The treatment system included: 1 - 20,000 gallon wier tank; 1 – 20,000 gallon influent tank; 2 – 5 micron bag filters; 2 carbon vessels; a final .25 micron polishing filter; and 4 – 20,000 effluent tanks as required for batch treatment. To reinforce existing sheet piling, 46 tie backs were installed between the concrete deadmen and permanent sheet pile barrier wall. Turbidity curtains were installed around a 7 acre section of the project site outside of the existing sheet pile wall and adjacent to the installation of a temporary 700 linear feet king pile turbidity wall.
Both shallow and deep water excavation was performed using a shore based 270 ton crawler crane with a standard clam shell excavation bucket equipped with a Clam Vision GPS excavation system. Upon completion of the removal of 4,000+ cy of PCB contaminated sediment, an environmental dredging bucket was used to perform a final cleanup pass to ensure all of the excavation requirements have been achieved. When excavation was completed a bathymetric survey was performed to generate an as built of the excavation footprint for submittal with the final project report.
Sediments were placed in 500 cy stockpiles for characterization. Sediments containing <25 ppm="" pcbs="" were="" used="" as="" fill="" material="" back="" on="" the="" site="" sediments="">25 ppm PCBs were loaded out into dump trailers for final landfill disposition.
A 600 lf x 14 feet deep LNAPL trench was installed. The trench was lined with stone and contained 5 collection sumps with ancillary piping and controls.
Outside of the sediment excavation limits a 60,000 sf area was covered using Triton Marine mattresses. The 15 feet by 35 feet by 1 feet mattresses were lowered into place from a crane mounted on a barge with a heavy duty lifting bracket. Placement of the mats was assisted by underwater divers. Armor stone was used to key in the mattresses.
Site restoration included the placement of geotextile barrier fabric, approximately 30,000 cy of cover soil, and the installation of seeding and mulch.

Health and Safety Overview:

Unique Characteristics: This was a fast tracked marine construction project in a confined area that resulted in No lost time accidents or recordable injuries.
Over 25,000 safe field man hours logged.
PPE was modified Level D.
Health and safety facilities included decon pads, portable decon stations and decon facilities.
How 40-Hour Training Was Implemented: All Sevenson project management, field supervision were trained in-house; union labor was trained through their respective union organizations.

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