Metal Bank Superfund Site, Delaware River, Philadelphia, PA

A.44 Metal Bank Superfund Site, Delaware River, Philadelphia, PA

Metal Bank Superfund Site, Cottman Avenue, Philadelphia PA

A.44.1 Contacts

Regulatory Contact:

USEPA Region 3, Philadelphia PA / Remedial Project Manager: Sharon Fang / 215-814-3018 /[email protected]

Site Remediation Contact: Sevenson Environmental, Niagara Falls, NY

A.44.2 Summary

Environment:	Tidal River
Scale:	Full
Contaminants of Concern:	PCBs, SVOCs/PAHs/hydrocarbons, dioxins
Source Control Achieved Prior to Remedy Selection?	No; source controls were part of final remedy
Final Remedy:	Mechanical dredging/cappingTechnology which covers contaminated sediment with material to isolate the contaminants from the surrounding environment. of source-area soils and near-shore sediments, installation of sheet pile wall, long-term monitoring
Expected Recovery Time:	100 years
MNR viewed as a success?	N/A; remedial construction completed in late-2009

A.44.3 Site Description

Primary source(s): Utility transformer oils

The Metal Bank Superfund Site is a 10-acre site located in an industrial area of northeast Philadelphia, Pennsylvania, adjacent to the Delaware River. Site operations, conducted from 1968 to 1972, included reclaiming copper parts from utility transformers and processing transformer oil for local utility companies. In 1977, USEPA determined that the site was the source of periodic PCB-impacted oil slicks in the Delaware River adjacent to the site. A U.S. Coast Guard study determined that groundwater below the site contained over 20,000 gallons of PCB-impacted oil that continuously leaked into the Delaware River. In March 2006, USEPA and the responsible parties signed a Consent Decree; the Revised Remedial Action Plan was finalized in Feb. 2008. Remedial construction was conducted at the site from July 2008 through Dec. 2009; the Remedial Action Completion Report for the site was submitted in March 2010. Over 30 years of litigation preceded final remedial action.

CSM summary: Remediation of ongoing releases of PCB impacted oils from on-site source areas into the Delaware River was achieved through both source area controls and institutional controlsNon-engineered instruments, such as administrative and legal controls, that help minimize the potential for human exposure to contamination and/or protect the integrity of the remedy., with long-term remedial performance monitoring.

A.44.4 Remedial Objectives

Concerns for this case study include both ecological and human health risks associated with PCBs and hydrocarbon oils in on-site soils, groundwater, and near-shore sediments.

RAO(s)/Project objectives:

The sediment cleanup action objectives for the site focused on achieving compliance with PCB cleanup criteria of 25 mg/Kg for on-site soils and 1 mg/Kg for near-shore river sediments in the bioactive zone. The project RAOs are defined in the 2008 Revised Remedial Action Plan.

A.44.5 Remedial Approach

Final selected remedy: Excavation and capping of on-site source area soils and near-shore sediments; installation of a sheet-pile wall at the edge of the site adjacent to the Delaware River; long-term monitoring to ensure the effectiveness of the remedy.

The final remedy, implemented in July 2009, included: installation of 700 lf temporary steel sheet piling to control turbidity; mechanical dredging of 4,000 yd³of PCB-impacted sediments (with shallow and deep water excavation) using an environmental clam bucket and 270-ton crawler crane (shore-based); sediment stabilization and transfer of dredged material for off-site TCSA disposal; installation of 600 lf LNAPL collection trench; placement of 60,000 ft²Triton marine mattresses (outside the sediment excavation area) with barge-mounted crane and diver assistance; continuous turbidity monitoring with four real-time monitors; on-site soil excavation of hot-spots, site restoration with geotextile liner, 30,000 yd³ cover soil, seeding, mulching; and long-term remedy performance monitoring. The final remedy addressed both on-site source controlThose efforts that are taken to eliminate or reduce, to the extent practicable, the release of COCs from direct and indirect ongoing sources to the aquatic system being evaluated. and off-site migration of contaminants into the adjacent waterway through source controls, institutional controls, and long-term monitoring.

Why the remedy was selected: The final remedy addresses PCB-contaminated soil, sediment, surface water, and groundwater at the site, with both source controls and institutional controls. The final remedy was based on the PCB criteria of 25 ppm for on-site soils and 1 ppm for near-shore sediments. Long-term remedial performance monitoring of on-site/down-gradient groundwater, as well as shore/near-shore sediments, addresses total PCB aroclors, as well as PCB congeners, dioxins, and SVOCs.

Remedial alternatives were evaluated for:

Overall protectiveness
Performance
Long-term effectiveness
Short-term risk management
Implementability
Consideration of public concerns
Restoration time-frame
Probable cost

Expected recovery time: 50 years

Projected monitoring costs: (TBD)

A.44.6 Monitoring

Final Remedial Construction Completion Report submitted March 2010. Long-term monitoring program underway; monitoring data not yet available.

Monitoring elements: Groundwater monitoring will be conducted to evaluate the effectiveness of the upland source removal on reducing concentrations of PCBs, dioxin, and PAHs in groundwater. Shoreline and near-sore monitoring will be conducted to evaluate concentrations of PCBs, dioxin, and PAHs in sediments to ensure the remedy remains protective of the aquatic environment in the Delaware River adjacent to the site.

RAOs/project objectives achieved? Remedial construction was completed in late-2009. The first two years of the long-term monitoring program has been completed. Overall, the remedy is viewed as a success.

A.44.7 Costs

Source removal and capping, sediment excavation and capping, waste transport and disposal, site restoration, and long-term monitoring

A.44.8 Advantages and Limitations

Site Specific Challenges:

Regulatory—PRP litigation and bankruptcy slowed progress.
Technical—Excavation of soil below water table, shallow/deep excavation of sediments in tidal river, expedited construction schedule, weather delays.
Community—Concern over habitat destruction and contaminant release in river.

Acceptance: Final remedy was accepted by public and PRP group.

A.44.9 References

USEPA, Mid-Atlantic Superfund, Metal Bank. http://www.epa.gov/reg3hwmd/super/sites/PAD046557096/index.htm

Publication Date: August 2014

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